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Canadian Public Policy Differential Grading Standards and Student Incentives Author(s): B. Curtis Eaton and Mukesh Eswaran Source: Canadian Public Policy / Analyse de Politiques, Vol. 34, No. 2 (Jun., 2008), pp. 215-236 Published by: University of Toronto Press on behalf of Canadian Public Policy Stable URL: http://www.jstor.org/stable/25463608 . Accessed: 15/06/2014 02:11 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. . University of Toronto Press and Canadian Public Policy are collaborating with JSTOR to digitize, preserve and extend access to Canadian Public Policy / Analyse de Politiques. http://www.jstor.org This content downloaded from 195.34.79.20 on Sun, 15 Jun 2014 02:11:30 AM All use subject to JSTOR Terms and Conditions

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Page 1: Differential Grading Standards and Student Incentives

Canadian Public Policy

Differential Grading Standards and Student IncentivesAuthor(s): B. Curtis Eaton and Mukesh EswaranSource: Canadian Public Policy / Analyse de Politiques, Vol. 34, No. 2 (Jun., 2008), pp. 215-236Published by: University of Toronto Press on behalf of Canadian Public PolicyStable URL: http://www.jstor.org/stable/25463608 .

Accessed: 15/06/2014 02:11

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact [email protected].

.

University of Toronto Press and Canadian Public Policy are collaborating with JSTOR to digitize, preserveand extend access to Canadian Public Policy / Analyse de Politiques.

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Page 2: Differential Grading Standards and Student Incentives

Differential Grading Standards and

Student Incentives

B. Curtis Eaton

University of Calgary, Alberta

MUKESH ESWARAN

University of British Columbia, Vancouver

Dans cette etude, nous avons examine les rSsultats scolaires des etudiants de trois university canadiennes. Ces donn?es montrent que les normes de notation varient de fa9on importante, a l'int6rieur d'une meme

university, selon les disciplines, et que, par consequent, on ne peut pas comparer de f&qon concluante les

moyennes ponder6es cumulatives (MPC) des etudiants qui suivent des cours de difterentes disciplines. II

n'est done pas equitable d'utiliser les MPC pour ^valuer le degre de r^ussite de ces Etudiants. Or, e'est

precis6ment de cette fac^on que Ton utilise la MPC, e'est-a-dire dans l'attribution des bourses, des distinctions et des diplomes, ainsi que dans la fixation de entires limitant l'acc&s a des cours, a des programmes ou a

des emplois. Ces variations de normes de notation soulfcvent, selon nous, une question fondamentale, celle de l'intSgrite' des university. Nous avons done cr?e un module de capital humain simple qui permet d'^valuer certaines distorsions dues a la variation des normes de notation, et nous montrons que, grace a des fa9ons

simples et non intrusives, il est possible de solutionner ce probleme.

Mots cles : normes de notation, capital humain, programmes comportant des cours de diverses disciplines, preselection, education

We present data on grades from three Canadian universities. These data suggest that grading standards differ significantly across disciplines within universities. To the extent that grading standards are not uniform across disciplines, the grade point averages (GPAs) of students with different course mixes cannot be

meaningfully compared, and therefore their GPAs cannot legitimately be used to assess their relative achievement. Yet GPAs are used in precisely this way?to award scholarships, honours and degrees, and to ration access to courses, academic programs, and jobs. Hence, we think differential standards raise a fundamental issue of integrity for universities. We develop a simple human capital model to assess some of the distortions arising from differential standards and suggest some non-intrusive ways to rectify the problem.

Keywords: grading standards, human capital, pooling, screening, education

Introduction

We examine some recent time-series data on

grades awarded by discipline in three Cana

dian universities. In these data, there are persistent and

significant differences across disciplines in both the

percentage of students who get high grades and in the

average grade awarded. Lamentably, it appears to be

the case that a very substantial portion of these differ ences is attributable to differences in grading standards.

To the extent that grading standards are not uni

form across disciplines, the grade point averages

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Page 3: Differential Grading Standards and Student Incentives

276 B. Curtis Eaton and Mukesh Eswaran

(GPAs) of students with different mixes of courses

across disciplines cannot be meaningfully compared, and therefore their GPAs cannot legitimately be used

to assess their relative achievements. Yet, both within

universities and to a lesser extent outside them, GPAs are used in precisely this way?to award

scholarships, honours and degrees, and to ration

access to courses, academic programs, and jobs. So

we think differential standards call into question the

integrity of the mechanisms that are used to assess

and report achievement in these three universities.

We have seen fragmentary data for a number of other

universities that are consistent with what we see in

the data for these three, which leads us to suspect that there is a grading standards problem in many,

perhaps most, Canadian universities.

We develop a human capital model to articulate

the ways in which differential grading standards

distort the decisions that students make. We show

that differential standards distort students' incentives

with respect to program choice, leading some stu

dents to choose the wrong program. In addition, we

show that differential standards distort students' in

centives to acquire human capital within their chosen

program, leading virtually all students to either

underinvest or overinvest in human capital.

In the concluding section we argue that it is pos

sible, in fact relatively easy, to use the very extensive

data that universities routinely collect to assess the

extent of the problem. We also offer some propos als for reform. They are non-intrusive in that they involve nothing other than alternative ways of ag

gregating the grades that individual instructors

routinely report. The proposed reforms blunt or even

reverse some of the incentives that produce differ

ential standards and grade inflation. And they are

easily implemented.

We are, of course, not the first to raise issues

concerning grading standards. It is useful to distin

guish two issues: grade inflation and differential

standards. The classic study in the economics lit

erature is Sabot and Wakeman-Linn (1991), which

presents data on grades received by students in a

number of disciplines for eight American colleges and universities for the academic years 1962-63 and

1985-86. In the earlier year, within a university or

college, there was a remarkable similarity in both

the averages and the distributions of grades across

different disciplines. Twenty-three years later, in

most disciplines grades were significantly inflated, and the degree of inflation was far from constant, with the result that in 1985-86 the authors could

readily identify, at a particular school, high grading and low grading departments. Anglin and Meng (2000) present similar results for universities in

Ontario. They look at grades in introductory courses

in 12 disciplines in seven universities for the aca

demic years 1973-74 and 1993-94, and they also

find evidence of significant grade inflation and sig nificant divergence in grades across departments

during this 20-year period. They report that in 1993

94, in the three softest grading departments (English, French, and Music), more than 60 percent of all stu

dents received an A or a B, and less than 13 percent received a D or an F, while in the three hardest grad

ing departments (Chemistry, Mathematics, and

Economics), fewer than 45 percent of all students

received an A or a B, and more than 30 percent re

ceived a D or an F.

Various explanations for grade inflation have

been suggested. Anglin and Meng (2000) offer the

hypothesis that grade inflation is the consequence of competition among departments for students.

Freeman (1999) offers a variation on this theme,

namely, that departments manage their enrolments

by adopting grading standards commensurate with

the market benefits of their courses, and he presents

supporting evidence. Siegfried and Fels (1979) and

Nelson and Lynch (1984) examine the hypothesis that grade inflation results from the attempts of in

structors to improve their teaching evaluations by

offering students higher grades, and they conclude

that there is some evidence to support the hypoth esis. Zangenehzadeh (1998) offers further evidence

in support of this hypothesis and suggests a solu

tion.

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Page 4: Differential Grading Standards and Student Incentives

Differential Grading Standards and Student Incentives 217

In addition, there has been some discussion of

the distortions that may be associated with differ

ential grading standards and grade inflation. Sabot

and Wakeman-Linn (1991) examine student re

sponses to differential grades and conclude that, in

choosing their courses, students clearly do respond, and in the expected way. Both Sabot and Wakeman

Linn (1991) and Anglin and Meng (2000) discuss

the distorted incentives that arise when grading standards differ across departments.

Much of the literature in this area has sought to

document grade inflation and differential grading standards. It has also examined the incentives that

may exist for these practices. Our paper examines

the implications of differential grading standards.

While some of this examination has been done by other researchers, notably Sabot and Wakeman-Linn

(1991), we provide a formal model that generates

qualitative predictions. We demonstrate how differ

ential grading standards distort students' choice of

program and their incentives to invest in human

capital.

Grades Data for Three Universities

We have extensive grades data for three Canadian

universities.1 For all three the data allow us to iden

tify differences in grades awarded by discipline. The

differences are quite large, and we call attention to

this phenomenon. Because we have better data for

University 3, we discuss results for this university

separately.

Universities 1 and 2

For Universities 1 and 2, we report on grades awarded by discipline in junior- and senior-level

courses over a number of recent years. To exclude

very small departments, we used the data for any

department at either level only if the department

assigned at least 500 grades in at least one year. Fit

ting a simple time trend to the university average

grades reveals that there has been statistically sig nificant grade inflation in both universities. The

inflation was substantial in University 2, especially at the junior level.2

As a convenient way of summarizing the data for

Universities 1 and 2, we ran a number of OLS (or

dinary least squares) regressions of the following sort:

?,, =?./>,+?? (1)

where / denotes the discipline, and t denotes time.

The left-hand side variable, yit, is the deviation in

period / from the corresponding university mean of

a measure that captures the grades awarded by

discipline /.

We use two different measures of grades: (a) the

percentage of high grades (As) awarded by the dis

cipline, and (b) the average grade awarded by the

discipline. The average grade is measured on a 4

point scale in University 1 and on a 9-point scale in

University 2. On the right-hand side of equation 1,

Dt is a dummy variable for discipline / (that is,

Dj = * #7,7 pertains to discipline /, and Di

= 0 other

wise), and ejt is a normally distributed error term

with mean zero. The coefficient fy estimates the ex

tent to which our measure of the grades in discipline / deviates from the university average. In an ideal

world, this coefficient would reflect differences in

student achievement across disciplines; however, it

may also reflect differences in grading standards.

In general, we expect that the coefficient conflates

both these effects. Since time and discipline grades are the only two sources of variability in yu, we do

not invoke the above regression to "explain" the vari

ance in grades. Rather, we run the regression merely

to obtain ^-statistics on the coefficients of the disci

pline dummies.

The regression results for the percentage of high

grades are presented in the second and third col

umns of Tables 1 through 4, while results for the

average grade awarded by discipline are presented in the fourth and fifth columns. The adjusted R

squared statistics are reported in the second-last line

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Page 5: Differential Grading Standards and Student Incentives

218 B. Curtis Eaton and Mukesh Eswaran

of each table. It is apparent from these tables that

grades differ significantly, in some cases dramati

cally, across disciplines in both universities.

In discussing differences in grades across disci

plines, we focus on the percentage of high grades

(As) awarded: for University 1 the percentage of

grades that are either A+, A, or A-; for University 2

the percentage of A+ grades awarded, because that

is the only available index of high grades for this

university. The patterns are similar for average

grades.

Results for University 1 are reported in Table 1

for senior-level courses and in Table 2 for junior level courses. The regression coefficient in the

second (fourth) column measures the divergence in

the percentage of As (average grade) given in that

discipline from the university mean for all disci

plines combined. The third and fifth columns give the corresponding ^-statistics. In the tables, the dis

ciplines are ranked from lowest to highest

percentage of As, and disciplines are somewhat ar

bitrarily grouped into low, medium, and high marks

groups. In the Low Marks group, the percentage of

As is no larger than 75 percent of the average for all

disciplines; in the High Marks group, the percent

age of As is no smaller than 125 percent of the

average; the remainder are in the Medium Marks

group. The asterisks in the tables indicate discipline dummies that are significantly different from 0 at

the 5 percent level of significance.

The university mean of the percentage of As

awarded in senior-level courses in University 1, call

this average PA , is 31.6 percent.3 Denote the av

erage percentage of As awarded in discipline i by

PAr At one extreme, in French this percentage is

13.8 percentage points lower than the university

average. At the other extreme, in Engineering Sci

ence this percentage is 21.5 percentage points

higher. Notice that for 11 of the 27 disciplines PA.

is less than PA at the 5 percent level of signifi cance, and that for 9 of 27 disciplines PAf is greater

than PA at the 5 percent level of significance. No

tice also that for 4 of the 27 disciplines PA.< 0.75 PA, and that for 4 of 27 disciplines PA. > 1.25; by this

criterion, nearly one-third of all disciplines have

grades that are either anomalously high or low.

As regards high grades given in senior-level

courses at University 1, the picture that emerges from Table 1 is one of disparity across disciplines.

The picture is much the same when one focuses on

the average grade given. The university average

(over all the disciplines) is 3.01 on a 4-point scale, the range over disciplines extends from 2.54 to 3.39,

and for 21 of the 27 disciplines the average grade is

significantly different from 3.01 at the 5 percent level of significance. The picture is similar, though not quite so dramatic, for junior-level courses at this

university (Table 2). The reader can peruse Tables 3

and 4 for University 2 to see that disparity over dis

ciplines dominates the grades picture at this

university as well.

Clearly, students' grades measure their achieve

ment in their courses. It is widely presumed that one

can meaningfully aggregate or average students'

achievements and compare these averages. Other

wise, we would not routinely report GPAs on

transcripts, and we would not use GPAs internally in the ways that we do?to award financial aid, to

identify the students whom we want to honour for

their achievements, to determine who will be ad

mitted to various programs and who will be rejected, and to determine who can continue their studies and

who must withdraw.

Given the very significant disparities that we see

in the grades data, we must ask whether they reflect

differences in achievement or differences in grad

ing standards. This is an important question. To the

extent that the variation across disciplines in grades is due not to differences in achievement but to dif

ferences in standards, we are awarding scarce

financial aid to the some of the wrong students, hon

ouring some of the wrong students, admitting some

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Differential Grading Standards and Student Incentives 219

Table 1 Senior Level: University 1

Disciplines Deviation of Percentage A Deviation of Percentage Grade from Univ. Mean (31.6%) from Univ. Mean (3.01/4.0)

Beta t-Stat. Beta t-Stat.

Low Marks

French -13.81* -11.60 -0.11* -3.98

Math & Computer Science -9.99* -8.39 -0.47* -16.69 Economics -9.74* -8.18 -0.27* -9.47

History -9.59* -8.05 -0.13* -4.58

Medium Marks

Business Administration -7.63* -6.41 -0.08* -2.96 Statistics -7.51* -6.31 -0.33* -11.76

Sociology -6.19* -5.20 -0.03 -1.06

Geography -6.03* -5.06 -0.05 -1.69 Mathematics -4.62* -3.88 -0.29* -10.14

Computer Science -3.80* -3.19 -0.07* -2.39

Psychology -2.93* -2.46 -0.14* -4.82

Philosophy -2.21 -1.86 -0.15* -5.39

Linguistics -1.67 -1.40 -0.10* -3.66

Biological Sciences -0.62 -0.52 -0.05 -1.90

English -0.49 -0.41 0.07* 2.43

Chemistry 0.36 0.30 -0.07* -2.61

Criminology 0.71 0.60 0.11* 3.77 Political Science 0.74 0.62 -0.01 -0.42 Mol. Biology & Biochem. 4.60* 2.73 0.06 1.49 Communication 4.65* 3.91 0.17* 5.95

Kinesiology 4.78* 4.01 0.09* 3.17

Archaeology 6.16* 5.17 0.12* 4.15

Physics 7.11* 5.97 0.02 0.70

High Marks

Humanities 8.62* 7.24 0.20* 6.90

Contemporary Arts 18.05* 15.16 0.35* 12.46 Education 20.91* 17.56 0.38* 13.34

Engineering Science 21.48* 18.04 0.38* 13.41

Adjusted R-Square 0.85 0.84

Number of observations 265 265

Note: *

Denotes significance at 5% level.

Source: Authors' compilation.

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Page 7: Differential Grading Standards and Student Incentives

220 B. Curtis Eaton and Mukesh Eswaran

Table 2 Junior Level: University 1

Disciplines Deviation of Percentage A Deviation of Average Grade from Univ. Mean (20.3%) from Univ. Mean (2.68/4.0)

Beta t-Stat Beta t-Stat

Low Marks

Business Administration -8.03* -8.23 -0.14* -5.51

Economics -5.47* -5.61 -0.25* -9.51

Criminology -5.24* -5.37 0.05 1.81

History -5.07* -5.20 -0.02 -0.85

Medium Marks

Philosophy -4.57* -4.68 -0.23* -8.78

Sociology -4.03* -4.13 0.13* 4.89

Psychology -3.73* -3.82 -0.06* -2.46

Communication -3.10* -3.18 0.14* 5.20

English -2.03* -2.08 0.18* 6.78

Geography -1.83 -1.88 0.05 1.77

Biological Sciences -1.75 -1.79 -0.18* -6.97

Mathematics -1.58 -1.62 -0.30* -11.48 French -1.20 -1.23 0.16* 6.28

Statistics -1.18 -1.21 -0.22* -8.55

Chemistry -0.66 -0.68 -0.05* -2.04 Math & Computer Science -0.39 -0.40 -0.22* -8.55

Linguistics -0.06 -0.06 0.10* 4.01

Political Science 0.12 0.12 0.02 0.69 Moi. Biology & Biochem. 0.26 0.19 -0.20* -5.39

Physics 2.55* 2.61 -0.03 -1.27

Archaeology 2.82* 2.89 0.10* 3.89

Computer Science 4.83* 4.95 -0.04 -1.39

High Marks

Kinesiology 5.31* 5.44 0.08* 3.24 Education 10.39* 10.65 0.28* 10.86

Humanities 13.35* 13.68 0.39* 14.98

Contemporary Arts 13.71* 14.05 0.48* 18.68

Engineering Science 28.48* 29.19 0.60* 23.03

Adjusted R-Square 0.86 0.88

Number of observations 265 265

Note: *

Denotes significance at 5% level.

Source: Authors' compilation.

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Differential Grading Standards and Student Incentives 221

Table 3 400-Level Courses: University 2

Disciplines Deviation of Percentage A Deviation of Average Grade from Univ. Mean (9.6%) from Univ. Mean (6.42/9.0)

Beta t-Stat Beta t-SM.

Low Marks

History -8.21* -5.96 -0.86* -8.86

English -6.70* -4.86 -0.64* -6.60

Business -6.30* -4.57 -0.26* -2.69

Philosophy -5.80* -4.21 -0.81* -8.29 Creative Writing -5.26* -3.81 0.06 0.59 Political Science -4.26* -3.09 -0.41* -4.25

French -2.97* -2.15 -0.47* -4.80

Medium Marks Economics -1.27 -0.92 -1.16* -11.93

Sociology -1.00 -0.73 -0.21* -2.20

Child and Youth Care -0.54 -0.39 0.32* 3.25

Education -0.16 -0.11 0.46* 4.68

Chemistry 0.01 0.01 -0.39* -3.98

Biochemistry and Microbiology 0.04 0.03 -0.45* -4.63 Public Administration 0.26 0.19 0.27* 2.77

Social Work 0.34 0.25 0.43* 4.45 Mechanical Engineering 0.61 0.45 -0.36* -3.73

Geography 0.91 0.66 0.37* 3.76 Anthropology 1.21 0.88 -0.45* -4.66

Biology 1.23 0.89 -0.06 -0.59

History in Arts 1.23 0.89 0.15 1.58

High Marks Nursing 3.74* 2.71 0.49* 5.04 Physics 3.77* 2.74 -0.73* -7.50 General Engineering 4.56* 3.30 -0.47* -4.77

Linguistics 5.03* 3.65 -0.01 -0.13 Theatre 5.34* 3.87 0.81* 8.30

Psychology 7.31* 5.30 0.34* 3.51

Eletrical and Computer Engineering 8.43* 6.11 -0.05 -0.56

Computer Science 10.17* 7.38 -0.09 -0.95

Music 13.71* 9.95 0.68* 6.94

Mathematics 22.23* 16.12 0.38* 3,86

Adjusted R-Square 0.75 0.78

Number of observations 210 210

Note: *

Denotes significance at 5% level.

Source: Authors' compilation.

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222 B. Curtis Eaton and Mukesh Eswaran

Table 4 200-Level Courses: University 2

Disciplines Deviation of Percentage A Deviation of Average Grade from Univ. Mean (5.6%) from Univ. Mean (5.14/9.0)

Beta t-Stat Beta t-Stat

Low Marks

History -4.64* -4.89 -0.35* -3.04

English -4.01* -4.23 0.15 1.28 Political Science -3.34* -3.52 -0.18 -1.53

Education -3.03* -3.19 0.70* 6.10 Creative Writing -2.37* -2.50 0.99* 8.67

Business -2.29* -2.41 -0.05 -0.40

Biochemistry -2.14* -2.26 -0.79* -6.88

Biology -1.61 -1.70 -0.15 -1.31

Medium Marks

French -1.16 -1.22 0.06 0.50

History in Arts -1.16 -1.22 0.45* 3.91

Anthropology -1.13 -1.19 0.31* 2.69 Social Work -1.13 -1.19 0.80* 6.96

Sociology -0.70 -0.74 0.34* 2.98

Geography -0.34 -0.36 0.52* 4.55 Economics -0.14 -0.15 -0.55* -4.78

Chemistry -0.11 -0.12 -0.76* -6.59

Psychology 0.39 0.41 -0.08 -0.72 Theatre 0.46 0.48 1.08* 9.40 General Engineering 0.74 0.78 0.25* 2.17

Philosophy 1.01 1.07 -0.07 -0.61

High Marks Computer Science 1.73 1.82 -0.12 -1.03

Physics 1.83 1.93 -0.33* -2.91 Mathematics 2.09* 2.20 -1.10* -9.59

Linguistics 3.26* 3.43 0.54* 4.72 Mechanical Engineering 3.99* 4.20 -0.16 -1.43 Child and Youth Care 4.40* 4.64 0.99* 8.63 Music 5.00* 5.27 0.96* 8.37 Electrical and Computer Engineering 5.87* 6.19 0.27* 2.39

Adjusted R-Square 0.50 0.78

Number off observations 196 196

Note: *

Denotes significance at 5% level.

Source: Authors' compilation.

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Differential Grading Standards and Student Incentives 223

of the wrong students to our programs, and encour

aging some of the wrong students to continue their

studies. More subtly, we are inducing students to

enrol in the wrong programs, to take the wrong courses, and to allocate their time in socially ineffi

cient ways.

Given the data, it is not possible to discern the

extent to which standards vary. However, drawing on impressions formed over many years in a number

of universities, it seems to us that differences in

standards are an important part of the story. For

University 1 we have some recent data on grades by

faculty that lend support to this view.

Table 5 presents grades data pertaining to five

faculties: Applied Science (APSC), Arts & Social

Science (FASS), Business (BUS), Education

(EDUC), and Science (SCI). The first column re

ports the percentage of As in all courses offered in

the five faculties in 2005, and the second column

reports the percentage of As received by students

who were registered in these faculties in 2005. The

ordinal rankings along the columns of these percent

ages are given in parentheses. Notice that students

registered in the Faculty of Education (EDUC) re

ceived the highest proportion of As (58.3 percent), and that the highest proportion of As are given in

courses offered in this faculty (48.8 percent). Both

proportions are far higher than in the other facul

ties. Similarly, students registered in the Applied Science Faculty (APSC) get more As (30.0 percent) than do students in any faculty other than Educa

tion, and more As are given in courses offered in

this faculty (29.7 percent) than in any faculty other

than Education.

Given the data in the first two columns of Table

5, we might be tempted to conclude that students in

the Education and Applied Science faculties are

somewhat better than students in the other faculties

of this university. The fourth through eighth columns

of the table point to quite a different conclusion.

These columns report data on the percentage of As

awarded to students registered in each of the facul

ties listed in the third column in courses they have

taken in different faculties. So 22.8 percent of the

students registered in Applied Science (APSC), for

example, received As in courses offered by the Fac

ulty of Arts & Social Science (FASS), while they

Table 5 Grade Comparisons within and across Faculties (University 1)

Within Faculties Across Faculties

% As for % As for Faculty APSC FASS BUS EDUC SCI Courses Students within Registered Faculty in Faculty

29.7(2) 30.0(2) APSC 33.4(2) 22.8(4) 19.8(3) 33.3(5) 23.4(3) 23.6(3) 22.5(5) FASS 17.2(4) 23.5(3) 14.8(4) 37.2(3) 14.7(5) 20.9(5) 26.5(3) BUS 35.2(1) 29.1(1) 23.8(1) 45.0(2) 32.0(1) 48.8(1) 58.3(1) EDUC 16.7(5) 28.6(2) 65.8(1) 18.2(4) 22.7(4) 24.0(4) SCI 25.7(3) 20.8(5) 20.6(2) 33.7(4) 24.8(2)

Notes: APSC = Applied Science. FASS = Arts & Social Science. BUS = Business. EDUC = Education. SCI = Science. The numbers in parentheses are ordinal rankings. Source: Authors' compilation.

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Page 11: Differential Grading Standards and Student Incentives

224 B. Curtis Eaton and Mukesh Eswaran

received As in 33.4 percent of the courses offered

by their own faculty. In terms of ordinal ranking out

of five, students registered in the Faculty of Educa

tion are near the bottom of the heap in the courses

they take in Science (SCI) and in Applied Science

(APSC), where they rank fourth and fifth, respec

tively, and although they do relatively well in the

courses they take in the Faculty of Arts and Social

Science (FASS), the percentage of As they get in

these courses (28.6 percent) is far below the per

centage they get in courses taken in their own faculty

(65.8 percent). It looks like Education students get a lot of As mostly because they take a lot courses in

the Faculty of Education where lots of As are

awarded. Similarly, it looks like the high percent

age of As received by students in Applied Science

is largely attributable to the fact that they take a lot

of courses in Applied Science where many As are

awarded.

Looking only at the second column of Table 5,

one would conclude that students in the Faculty of

Business are modest achievers, in the middle of the

pack. But when we look at the cross-faculty com

parisons, it is apparent that these students as a group are very high achievers, and the fact that they finish

in the middle of the pack in column 2 is apparently attributable to the relatively high standards in the

Business Faculty.

University 3

For University 3, we have more detailed data. For a

three-year period, we have every grade awarded at

the undergraduate level in this university. For each

grade we know the discipline, the level of the course

(junior or senior), and the student who received the

grade.

For 78 percent of students, we also have an in

dex of ability. These are the students who were

admitted to university directly from high schools in

the province in which the university is located. The

index of ability is the student's average grade in the

best five of ten core high school courses. We restrict

attention to grades in senior-level courses received

by these students. Results for junior-level courses

are similar.

A cursory examination of the data reveals that

differences across disciplines in grades in this uni

versity cannot be explained by differences in ability. In fact, in these data it is the case that disciplines in

which average student ability is low tend to award

higher grades than do disciplines in which average student ability is high. Across the 48 disciplines in

the data, the correlation coefficient of average grade and average ability is negative, -0.29. So in this

university, it appears to be the case that the real dif

ferences across disciplines in grading standards are

larger than the apparent differences.

To estimate differences in standards across de

partments, we ran the following OLS regression:

gu^a + yAi +

ppj+ey. (2)

The left-hand side variable, g.., is a grade received

by student i in some senior-level course in disci

pline j, A{ is the student's ability, and D. is a

departmental dummy variable. BUS 1 is the disci

pline that is left out, so fl. is an estimate of the

difference in grading standards between discipline

j and BUS 1 (see Table 6).

Were we to name the 48 disciplines, the identity of the university would be obvious to many. To pre serve anonymity, we have grouped disciplines into

six broad categories, and within those categories

assigned numbers to disciplines. The categories are

science (SCI), business (BUS), humanities and the

fine arts (HUFA), social science (SOCS), engineer

ing (ENG), and professional faculties (PROF).

Regression coefficients are reported in column 2

of Table 6, /-statistics in column 3, and the 95 per cent confidence intervals in columns 3 and 4. We

have reported confidence intervals to make it easy

to compare grading standards across arbitrary pairs of

disciplines. Naturally, the coefficient associated with

student ability is positive, and highly significant. The

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Differential Grading Standards and Student Incentives 225

Table 6 Regression of Grades against Ability and Discipline Dummy Variables

Regression Coefficients t-Statistic 95% Confidence Interval

Constant 0.05 1.011 -0.05 0.15

Ability 0.03* 60.99 0.0336 0.0359 SC110 -0.50* -12.31 -0.58 -0.42 SC112 -0.15* -4.05 -0.22 -0.08

SCI1 -0.09 -1.99 -0.18 0.00 SCI 3 -0.08* -2.17 -0.16 -0.01

SCI 5 -0.08* -2.25 -0.15 -0.01 SCI 4 -0.07 -2.08 -0.13 0.00

SC111 0.02 0.46 -0.07 0.11 SC113 0.09* 2.61 0.02 0.16 SCI 7 0.12* 4.27 0.06 0.18 SCI 6 0.13* 3.55 0.06 0.20 SCI 8 0.27* 8.98 0.21 0.33 SCI 2 0.36* 9.77 0.29 0.43 SCI 9 0.49* 16.84 0.44 0.55 BUS 2 0.16* 5.96 0.11 0.22 BUS 5 0.35* 14.48 0.30 0.39 BUS 8 0.35* 13.07 0.30 0.40

BUS 7 0.41* 15.24 0.36 0.46 BUS 3 0.44* 16.36 0.38 0.49 BUS 6 0.44* 16.69 0.38 0.49 BUS 4 0.64* 24.98 0.59 0.69

HUFA5 0.06 1.69 -0.01 0.14 HUFA10 0.06 1.80 -0.01 0.13

HUFA4 0.29* 9.61 0.23 0.34 HUFA1 0.30* 8.14 0.23 0.37 HUFA7 0.39* 11.11 0.33 0.46 HUFA9 0.45* 15.12 0.39 0.51 HUFA8 0.46* 15.58 0.40 0.52 HUFA6 0.51* 17.48 0.45 0.57 HUFA2 0.60* 20.28 0.54 0.65 HUFA3 0.61* 22.68 0.55 0.66 S0CS3 0.13* 4.53 0.07 0.19 S0CS6 0.18* 3.88 0.09 0.27 S0CS5 0.29* 10.15 0.23 0.34

S0CS1 0.29* 9.82 0.24 0.35 S0CS2 0.31* 8.91 0.25 0.38

S0CS7 0.34* 11.74 0.29 0.40 S0CS9 0.39* 14.22 0.34 0.45 S0CS4 0.43* 15.84 0.38 0.48 S0CS8 0.45* 17.03 0.40 0.50

ENG4 -0.02 -0.55 -0.08 0.04 ENG1 0.00 -0.04 -0.08 0.08

ENG3 0.11* 3.11 0.04 0.18

... continued

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Page 13: Differential Grading Standards and Student Incentives

226 B. Curtis Eaton and Mukesh Eswaran

Table 6 (Continued)

Regression Coefficients t-Statistic 95% Confidence Interval

ENG6 0.18* 5.69 0.12 0.25

ENG5 0.25* 5.93 0.17 0.34

ENG2 0.27* 7.36 0.20 0.34

PROF 2 0.73* 24.75 0.67 0.79

PR0F1 0.77* 29.15 0.72 0.82

fl-Squared .1546

No. observations 135,581

Notes: SCI = Science. BUS = Business. HUFA = Humanities and the Fine Arts. SOCS = Social Science.

ENG = Engineering. PROF = Professional Faculties. *

Denotes significance at the 5% level.

Source: Authors' compilation.

point estimate is 0.03, so a difference of 10 points in student ability (measured on a 100-point scale)

is associated with an increase in the student's grade of 0.3 (on a 4-point scale).

The coefficients for the discipline dummy vari

ables are grouped in the six categories described

above, and within each category they are ordered

from lowest to highest. Across all disciplines, the

smallest and largest coefficients are -0.50 for SCI

10 and 0.77 for PROF 1. Since only about 5 percent of all grades at the senior level in this university are

Ds and Fs, it is probably better to think in terms of

a 3-point scale rather than a 4-point scale. So the

difference in standards between SCI 10 and PROF

1, 1.27 points on a 3-point scale, is quite large and

clearly statistically significant. The story is similar

though not quite as dramatic within five of the six

disciplinary groupings. The range of the differences

in disciplinary coefficients is 0.99 in SCI, 0.64 in

BUS (since the omitted discipline is BUS 1), 0.55

in HUFA, 0.32 in SOCS, and 0.29 in ENG. Differ

ences in the coefficients for an arbitrary pair of

disciplines that are larger than about 0.08 are statis

tically significant at the .05 level. Notice also that

if the difference in the coefficients of two disciplines is larger than about 0.15, there is no overlap in the

corresponding confidence intervals. There is no

question then that within these disciplinary group

ings, there are significant differences in standards.

Although the grading standards in PROF 1 and

PROF 2 are not significantly different, in both the

standards are out of line with respect to all but one

of the other 46 disciplines?the only overlap in con

fidence intervals is between BUS 4 and PROF 2.

Similarly, the standards in the two disciplines with

the highest standards (lowest coefficients), SCI 10

and SCI 12, are clearly out of line with respect to

the other 46 disciplines.

Given the way that grades are used, particularly in the universities themselves, these differences in

standards are, we believe, significant in more than

just a dry statistical sense. Consider, for example, the honour of graduating with distinction. In Table

6, all of the BUS disciplines are in the same faculty, as are all of the SOCS disciplines, and all of the

ENG disciplines. In these faculties, a GPA of 3.6 in

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Page 14: Differential Grading Standards and Student Incentives

Differential Grading Standards and Student Incentives 227

courses taken in the last two years of the undergradu ate program is necessary to achieve this honour.4 It

seems clear that in the competition for the honour

of graduating with distinction, within each of these

faculties students in disciplines with the highest standards (lowest coefficients) are disadvantaged

with respect to students in disciplines with the low

est standards (highest coefficients). The GPA

window for this honour is just 0.4 points wide, and

relative to the size of this window the differences in

disciplinary coefficients are large. In ENG and

SOCS the ranges of the differences in disciplinary coefficients are approximately three-quarters of the

width of the with distinction window, and in BUS

the range is more than 1.5 the width of the window.

A more detailed comparison of SOCS 3 and

SOCS 8, the Social Science disciplines with the

highest and lowest standards, is enlightening be

cause both graduate large numbers of students, and

the average ability of students majoring in these dis

ciplines is similar. Over this three-year period, 504

students received a Bachelor of Arts in SOCS 3 and

436 received a degree in SOCS 8. The average abili

ties of students in third year or higher of their

program, who declared a major in one these disci

plines, was 76.1 in SOCS 3 and 78.4 in SOCS 8. Of

the students graduating in SOCS 3 and SOCS 8, 4

percent and 22 percent, respectively, graduated with

distinction. Because the average ability of students

in SOCS 8 is somewhat higher that it is SOCS 3, one would expect to see a higher proportion of stu

dents graduating with distinction in SOCS 8, but the

results in Table 6 suggest that most of the difference

in the proportion of students who achieve this honour

is attributable to differences in grading standards.

The 3.6 GPA is a useful benchmark for the com

petition for financial aid as well. The bulk of the

financial aid available to undergraduates in this uni

versity is awarded in an open competition, based

largely on relative academic merit. Academic merit

is, of course, measured by GPA, and the cut-off GPA

is usually somewhere in the neighbourhood of 3.6.

It appears to be the case that, in the lives of the stu

dents in this university, the differences in discipli

nary standards seen in Table 6 have very significant

consequences for the allocation of academic hon

ours and financial aid. In the following section, we

use the human capital model to examine some of

the ways in which differential standards distort stu

dents' incentives and choices.

A Simple Human Capital Model

Our model is in the tradition of economic models of

grading standards (Becker 1975; Becker and Rosen

1992; Betts 1998; Costrell 1994; Dickson 1984;

McKenzie 1975), but our concerns are different. We

focus on differential grading standards and their effects.

We treat the university as an intermediary in the

market for human capital. It provides the opportu

nity for students to develop their human capital, observes their realized human capital, and assigns

grades that reflect their achievements. Assigned

grades are then used by employers to assess students'

human capital. With suitable reinterpretation, how

ever, our model also applies to students who are

competing for admission into graduate programs,

scholarships, and so forth.

Students' preferences are identical and defined

over the present value of lifetime income, v, and the

effort expended, e, to develop their human capital.

They are captured in the following utility function:

U(y,e) =

y--e2. (3)

The present value of the earnings generated by a

unit of human capital is equal to /}. The cost incurred

in training a student is y, which is independent of

the effort exerted by the student, the student's po tential, and the program chosen by the student. This

cost is borne by the student.

There is a university that offers two programs,

Program 1 and Program 2. Each student is described

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Page 15: Differential Grading Standards and Student Incentives

228 B. Curtis Eaton and Mukesh Eswaran

by an innate aptitude, or ability-pair (ap a2), where

a{ is her aptitude for Program 1 and a2 is that for

Program 2. We shall also refer to a, and o^ as Apti tude 1 and Aptitude 2, respectively. The density function describing the distribution of aptitudes

among potential students is

f(al9a2)>0 a{>0 t*2>0.

In the university, students expend effort to de

velop their human capital. Human capital, h{{e), as

a function of student effort in Program i is given by

/*,(<?,) =

a,e/. (4)

A given effort generates more human capital for stu

dents with higher aptitudes. There is an outside

option (which we dub Program 0) that is available

to all students and offers a lifetime utility equal to (0.

Optimality The cost-benefit optimal allocation maximizes the

sum of realized utility over all students. Because

there is no interaction among individuals, we can

characterize the optimal allocation by maximizing the utility of each student. This, of course, implies that cost-benefit optimal allocation is Pareto

optimal. If student a is assigned to university

Program /, her utility is just

Ui(ehai) =

(fafii-y)-^ei2. (5)

The first term on the right, (fiai?i -

y), is lifetime

income net of the cost of her education, and the sec

1 2 ond term,

? e{ , is the utility cost of her effort. The

effort level that maximizes total utility is

*>,) =/to,. (6)

the optimal quantity of human capital is

*>,) =

#*?, (7)

and maximized utility is

tf>,) =

{/*2a,2-r. (8)

Optimal effort, human capital, and maximized util

ity from either program are increasing functions of

the student's aptitude for that program. This is be

cause the returns to effort are higher for students

with greater aptitude.

The outside option (Program 0) will dominate uni

versity Program / if (O > U{ (at), or if

ai < a, where a = A/2(y

+ o>)/j3. (9)

The optimal assignment of students to programs is illustrated in Figure 1, which displays the apti tude pairs (av a2) of students. The ray OA is the

45? line. Students below the line have better abilities

for Program 1, students above OA for Program 2,

Figure 1 The Optimal Assignment of Students in Programs

| Aptitude 2

A

/ /

/ /

PROGRAM 2

D-^c / j

J / j

PROGRAM 0 PROGRAM 1

/ j /

0 B Aptitude 1

Source: Authors' compilation.

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Page 16: Differential Grading Standards and Student Incentives

Differential Grading Standards and Student Incentives 229

and students along OA have equal abilities for both

programs. Students with low abilities, however, can

not generate sufficient human capital to justify

foregoing their outside option. Those with ax less

than OB (= a) would be better off with their out

side option compared to enrolling in Program 1.

Likewise, students with a2 less than OD (=00 would be better off with their outside option com

pared to enrolling in Program 2. Thus it is optimal for students with ability pairs in the square OBCD

to not enrol in university. It is optimal for students

with ability pairs to the right of BC and below CA

to enrol in Program 1, and for those with ability pairs above DC and CA to enrol in Program 2. Among students enrolled in either of the university pro

grams, the achieved level of human capital will be

increasing in their aptitude for that program.

Equilibrium In this framework, the grading standards in Programs 1 and 2 are, in essence, the price system that guides students' choices. The informational assumptions in

our model are the following. Prior to enrolment, the

university knows nothing about the students, and it

accepts all students who choose to enrol. The uni

versity observes the realized human capital of

students when they complete their programs, but not

their true aptitudes, and it assigns grades that re

flect these achievements. Students know their own

aptitudes, the utility of the outside option (co), the

present values of their worth per unit of human capi tal (/}), and the cost of a university education (f).

Employers cannot observe human capital and instead

rely on assigned grades to assess students' human

capital. That employers never observe the human

capital achievements of their employees is, obvi

ously, a strong assumption, but it will be apparent that none of the qualitative features of the distor

tions that we highlight are driven by it as long as

employers cannot immediately assess their new

hires.

In addition, we assume that students pay the cost

of their university education, and that the labour

market is competitive, so that students in aggregate

capture as earnings all that they produce.

The role of the university is then to educate stu

dents, observe their human capital achievements,

and assign grades. The questions we ask concern

the university's grading standards. What are the

properties of optimal standards? What distortions

arise when non-optimal standards are used?

Grading Standards. A grading standard for program / is a mapping from the realized human capital, A., of a student who has completed the program to a

grade or mark, m^h). A student's grade in Program / is a linear function of her human capital:

mi(hi)=eihi 0,>1. (10)

The parameter 0, is an inverse measure of the grad

ing standard in Program i. We assume that Program 2 has the lower standard and, since it is differences in standards that distort student incentives (as we

shall see), we fix the standard in Program 1. Ac

cordingly, we assume that 6X = 1. Notice that in

Program 1, a student's grade is identical to her hu

man capital. Relative to Program 1, standards in

Program 2 are possibly diluted (02 > 1). In particu

lar, except in the case where 62 =

1, a student's

grade in Program 2 is less than her human capital.

In this environment, differential grading stand

ards distort student incentives in that students are

induced to manage their grades instead of their hu

man capital.

Equilibrium Choices

Since firms cannot observe human capital, they rely on the grades provided by the university to infer the

human capital of students whom they hire. Hence, in the labour market students are pooled by their

grades. And, if programs use different grading stand

ards, students in the same grade pool will have

different amounts of human capital. Pooling across

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Page 17: Differential Grading Standards and Student Incentives

230 B. Curtis Eaton and Mukesh Eswaran

different disciplines, especially for students with

only a Bachelor's degree, is a very reasonable sce

nario. An entry-level job in the banking sector, for

example, requires generic skills that could be satis

fied by students with degrees in economics,

psychology, mathematics, English, physics, or busi

ness, to name just a few disciplines.5

Some circumstantial evidence can be brought to

bear on our claim that students are pooled in the

labour market. Sabot and Wakeman-Linn (1991) have examined the effect of a high grade in an in

troductory course on the probability of subsequent enrolment by the student in that discipline's courses.

They find that a high grade in a particular course

induces students to choose subsequent courses in

that discipline with higher probability even after

students account for the comparative advantage in

formation contained in the grade (by evaluating students' relative position in that course in compari son to the relative ranking of their overall GPA).

The inducement offered by the absolute grade sug

gests that students expect that potential employers cannot glean full information about their achieve

ments through their transcript?presumably because

of pooling.

Let h(m) denote the average human capital ac

quired by the students who receive grade m. Then, since firms pool students with identical grades, life

time earnings of a student who receives grade m will

be Ph(m). To achieve grade m in Program /, a stu

m dent must acquire ~7T units of human capital, which

m

requires that she expend , ~ . units of effort.

Hence, the typical student's maximization problem is to choose a program / (7 = 7,2), and a grade m, to

maximize her utility:

max fh(m)-y-\[^

. (11)

A student can get grade m in either program and, since earnings net of the cost of an education,

(Ph(m) -

y), are independent of the program cho

sen, a student will be indifferent between getting

grade m in Program 1 or in Program 2 if the effort

required to get grade m is identical in the two pro

grams, that is, if

m _ m

ccx a202'

Hence, the locus of indifference is

ax

?2=^. (12)

This locus is represented in Figure 2 as dashed

ray OE, which has a slope less than 1 if 92 > 1. Let

us isolate on this ray a student, represented by point

F, with the aptitude pair a = (ax,a2) such that the

grade m solves her maximization problem. She is

indifferent between getting grade m in Program 1

and getting grade m in Program 2. Students

as(a,,a2) on the horizontal line segment HF

(with d2 =a2, dx<ax) are just as able as stu

dent F in Program 2 but less able in Program 1.

Consequently, all these students will choose to get

grade m in Program 2. In other words, if opting for

grade m in Program 2 solves the maximization prob lem for student a, it also solves the maximization

problem for every student d=(dx,d2) with

d2 =a2, dx<ax. Analogously, since grade m

also solves the maximization problem for student a

in Program 1 (because, by assumption, she is indif

ferent between the two programs), this program will

also solve the maximization problem of every stu

dent d = (dx,d2) with dx =ax, d2 <a2. These

students have aptitude pairs lying on the vertical line

GF.

The grade pool m will comprise all the students

with ability pairs on the lines GF and HF. All

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Differential Grading Standards and Student Incentives 231

students on GF have aptitude a{ for the program

they have enrolled in (Program 1), while on HF all

ax students have aptitude ~T" for the program they have

^2

enrolled in (Program 2). By integrating the density

function f(ax,d2) over the line segments FG and

HF in Figure 2, we can compute the proportions of

students from Programs 1 and 2, Px(ax,02) and

P2(ax,02), respectively, in grade pool m.6

Figure 2 The Pooling of Students with a Given Grade

I Aptitude 2

PROGRAM 2

E s

s s

H .y{

^' ? PROGRAM 1

* '

* \

k,_!_ 0 G Aptitude 1

Source: Authors' compilation.

We can now determine the average level of hu

man capital in any grade pool. To earn grade m, a

student in Program 1 must acquire m units of hu

man capital, and a student in Program 2 must acquire

m/02 units. So the average human capital of stu

dents in grade pool m is

h(m) = mPx(ax,92) +

(m/02)P2(ax,02)

or

h(m) = mD(ax,e2), (13)

where

D(aI,fl2)i/,1(a?82) + (l/fl2)/,2(a1,fl2). (14)

Note that, since 62 > 1, D(ax,62)<\. Further

more, D(ax,02) = 1 if 92

= 1 and is declining in

62. Consequently, the average amount of human

capital in grade pool m is less than or equal to m. If

there is dilution of grading standards in Program 2

(92 >1), this average is strictly less than m because

the human capital that students from Program 2 have

is less than m.

There is a continuum of students, so no individual

student contributes a measurable amount to the hu

man capital in any grade pool. Consequently, in

choosing their grade pool m, each student will take

the proportions Px(ax,02) and P2(ax,02), and

hence D(ax ,02), as given. Therefore, from the per

spective of an individual student, the rate of change of lifetime earnings with respect to grade m is

Using this, the first order condition with respect to

m for a student who enrols in Program 1 is just

0D(al9O2)~ =

O9 ax

which can be written as

m=a?l3D(ax,e2)- (15)

This equation identifies the grade m that solves

the maximization problem of students who enrol in

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Page 19: Differential Grading Standards and Student Incentives

232 B. Curtis Eaton and Mukesh Eswaran

Program 1 in terms of their aptitude for that pro

gram. By substituting ax =

a202 in the above

equation, we obtain the grade m that solves the

maximization problem of the students enrolling in

Program 2 in terms of their aptitude for that pro

gram as

m = (a202)2/SD(a202,02). (16)

The locus OE in Figure 3 partitions the (ax>a2)

space into students who prefer Program 1 to Pro

gram 2 and vice versa. Equations 15 and 16 pin down

the grade m achieved by students in terms of their

aptitude for the program they enrol in. This grade,

naturally, is increasing in the aptitude for the pro

gram in which the student is enrolled.

We can use Figure 3 to identify the equilibrium allocation of students to programs and compare this

outcome with the optimum. In the figure as drawn,

Figure 3 Comparison of the Optimal and Equilibrium Allocations of Students to Programs

Aptitude 2

A /

/

j / /

/ PROGRAM 2 '

/ E

/ *x^ I PROGRAM 1

/ PROGRAM 0 j ;

\iS^_I i_ 0 b I Aptitude 1

Source: Authors' compilation.

we are assuming that standards in Program 2 are

diluted; that is, that 02 > 1. We have seen that in

the optimum, students with ability less than OB

would opt for their outside option rather than enrol

in Program 1. In equilibrium, students in Program 1

earn lower returns on their human capital since they are pooled with students from Program 2, which has

lower standards for the grades of its students. Con

sequently, the ability cut-off for students to forego their outside option in order to enrol in Program 1

is higher in equilibrium than in the optimum and is

denoted by 01 in Figure 3. Students in Program 2

are pooled with Program 1 students, who have higher human capital. Thus students in Program 2 receive

a higher return from enrolling in Program 2 than is

warranted by their human capital. Consequently, the

ability cut-off in equilibrium (denoted by OK) for

students to forego their outside option in order to

enrol in Program 2 is lower than that in the opti mum (OD). In equilibrium, students with aptitude

pairs falling in the rectangle OIJK will opt for Pro

gram 0 (their outside option). Students with aptitude

pairs falling in the region to the right of IJ and be

low JE will enrol in Program 1; those with aptitude

pairs lying above KJ and JE will enrol in Program 2.

Equilibrium versus Optimum

Many authors, including Sabot and Wakeman-Linn

(1991) and Anglin and Meng (2000), have argued that identical grading standards are, in some sense,

optimal. In our model, identical grading standards

(02 =

1) will lead to the optimal allocation. We see

from equation 12 that ray OE will coincide with ray

OA in Figure 3 when 02 = 1. Also, we see from

equation 14 that D(a{, 1) = 1, and so equation 13

says that the average human capital embodied in a

grade pool coincides with the grade. Further, when

02 =

1, rectangle OIJK coincides with rectangle OBCD. Even though students from different pro

grams are pooled, their grade is a perfect indicator

of their productivity.

Various authors have commented on the distor

tions with respect to program choice one should

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Differential Grading Standards and Student Incentives 233

expect to see when grading standards differ (see

especially the discussion in Anglin and Meng 2000).

Three sorts of distortion are apparent from Figure 3:

1. Optimality dictates that students in area KLCD

stay out of university (Program 0), but in equi librium they choose Program 2. By choosing

Program 2 instead of their outside option, these

students are pooled with others from Program 1

who acquire more human capital than they do.

Hence there is an implicit cross-subsidy that is

sufficient to induce these students to choose Pro

gram 2 instead of Program 0.

2. Optimality dictates that students in area BIJL be

allocated to Program 1, but in equilibrium they choose Program 0. The story here is the reverse

of the one told above. If these individuals were

to choose Program 1, they would be pooled with

others from Program 2 who would acquire less

human capital than they would, and the burden

of the cross-subsidization that they would have

to bear is so large that they are better off choos

ing their outside option instead of Program 1.

3. Optimality dictates that students in area ACLJE

be allocated to Program 1, but in equilibrium

they choose Program 2 instead. Once again the

implicit cross-subsidy from pooling is driving the misallocation.

So, in this model, differential grading standards

clearly distort student incentives with respect to pro

gram choice. In addition, with differential grading standards students' incentives to acquire human

capital within their chosen program are distorted, because the returns to effort are reduced for students

in Program 1 and raised for those in Program 2. Thus

students in Program 1 will underachieve in equilib rium relative to their optimal achievement, whereas

those in Program 2 will overachieve. The cross

subsidization makes students of Program 1 worse

off in equilibrium and students of Program 2 better

off. All these distortions are due to the wedge that

is created by differential grading standards between

true human capital and signalled human capital.

Clearly, the only way in which these misallocations

in equilibrium can be eliminated is by having iden

tical grading standards, that is, by setting 02 = 1.

In the formal analysis above, we have taken the

grading standards as given. It would be possible to

construct a model in which these standards are

endogenized. Disciplines might be interested in in

creasing the number of students enrolled in their

programs, since funding depends on the student-to

faculty ratio and departments see research

advantages to having more faculty members. As a

first cut one might reasonably attribute to each dis

cipline an objective function that is the difference

between this enrolment-dependent funding and the

costs of managing the program. Student enrolment

depends on the grading schemes used in the two

programs, as analyzed above. Such a model would

predict that, if the standards in the two programs were chosen under Nash conjectures, the equilib rium level would entail a dilution of grading standards in both. This would rationalize an infor

mal observation made by Shea (1994). He reports

that, after the publication of Sabot and Wakeman

Linn's (1991) study documenting differential

grading practices in Williams College, one did not

subsequently see stricter grading in the easy grad

ing disciplines of this college. Rather, what

transpired was an easing up of grading in mathemat

ics and science (the traditionally hard grading

disciplines). Grade inflation in these disciplines af

ter 1985-86 (the last year for which Sabot and

Wakeman-Linn presented data) was 9 percent, while

that in arts and languages (the traditionally easy

grading disciplines) was 5 percent.

If different departments in a university make de

centralized decisions about their grade distributions, there is thus reason to believe that dilution of grad

ing standards will obtain. This is because such a

grading policy is individually rational for each dis

cipline. By luring away potential students, each

department inflicts a negative externality on others

that it does not take into account. An adverse

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Page 21: Differential Grading Standards and Student Incentives

234 B. Curtis Eaton and Mukesh Eswaran

consequence of this pattern is that, at each grade

level, a student embodies less human capital.7 Therefore, there are grounds for the university ad

ministration to step in with measures that would

internalize these externalities and prevent a race to

the bottom. As discussed below, these measures need

not be as draconian as imposing strict, common

guidelines for grade distributions in all disciplines.

Conclusions

We analyzed here recent time-series data on grades awarded in three Canadian universities. We see very substantial and persistent differences across disci

plines in both the average grade awarded and in the

number of high grades awarded. It appears to us that

much?perhaps most?of the differences in grades across disciplines within each of these universities

are attributable to differences in grading standards.

We have seen fragmentary data for a number of other

Canadian universities that support the same conclu

sion. Further, differential grading standards are

apparent in various studies of grade inflation (see

especially Anglin and Meng 2000; and Sabot and

Wakeman-Linn 1991). It appears to us that substan

tial differences in grading standards across

disciplines are the norm in our universities.

If this assessment is correct, we have a serious

problem: to the extent that grading standards differ

across disciplines, grades are not a legitimate unit

of account as regards the academic achievement of

students, and they cannot be legitimately used to

award scholarships, honours and degrees, nor to ra

tion access to courses, academic programs, and jobs.

Where do we go from here? It might be argued that what is done in different disciplines is so dif

ferent that comparisons of achievement across them

are simply impossible. If this argument were ac

cepted, then it would seem that we ought to abandon

the pretense of comparability; that is, we ought to

abandon the practice of requiring different disci

plines to report students' achievements to the

registrar using the same set of grades. This, we think, would cause more problems than it would solve. If

users of transcripts are to compare the transcripts of different students, they require some index of

aggregate achievement, and if the university does

not supply the index, the users themselves will. At

least implicitly, users will devise their own aggre

gate indices of achievement. This would be

unfortunate, because universities have far more in

formation at their disposal on matters pertaining to

the measurement and comparison of student achieve

ment than do typical users of transcripts.

It seems to us that the first thing that needs to be

done is to actually decompose differences in grades awarded across different disciplines into a compo nent attributable to differences in standards and a

component attributable to differences in achieve

ment. Only then will we actually grasp the extent of

the problem. Only then will we have the informa

tion necessary to reform our grading practices.

Importantly, universities have in their data banks the

necessary information.

Given the way universities operate, it would be

difficult to impose uniform grading standards. But

it is not necessary that grading standards actually be uniform. If it is possible to estimate grading standards by discipline, and we think it is, then it is

possible to construct for each student a Standards

Adjusted Grade Point Average (SAGPA)?an aggre

gate index of achievement that is purged of the biases

associated with grading standards that differ across

disciplines.8 Universities ought to be calculating

SAGPA, and they ought to be reporting it on

transcripts.9

In the meantime, until the details of calculating SAGPA are worked out, we would argue that univer

sities ought to calculate and report for each student

the student's average relative performance (ARP), and

that ARP ought to be given the same prominence that

is now given to GPA on transcripts. This could be as

simple as reporting an average of the student's per

centile ranking in each of her courses. Users could

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Differential Grading Standards and Student Incentives 235

then at least spot students who have a high (low) GPA,

not because their achievement is at the high (low) end

of the distribution of achievement in the classes that

they take, but because they are enrolled in courses

where everyone gets a high (low) mark.

There is something to be said in favour of calcu

lating and reporting on transcripts all three indices:

GPA, SAGPA, and ARP. Users of transcripts would

then have the opportunity to choose among and/or

combine the indices for their own purposes. In our

opinion, there is nothing to be said in favour of con

tinuing to report GPA as the only index of aggregate achievement.

It is also worth noting that the use of these alter

native measures of aggregate performance would

blunt and even reverse many of the incentives that

have given rise to differential standards and grade inflation. If users of transcripts were paying atten

tion to SAGPA and/or ARP, disciplines would not

to be able to attract students by diluting their standards,

and able students who are strategically managing their aggregate performance for whatever reason

would not find it attractive to take courses in disci

plines with low standards. Adopting these measures

of aggregate performance would, we think, go some

way toward halting and even reversing the grade in

flation we have seen in our universities over the past three or four decades.

Finally, we note that in the model of this paper, we assumed that students know their innate abili

ties. In reality, few university students (especially

undergraduates) have this degree of self-knowledge.

They go to university to take a variety of courses

and learn what they are good at. Then they choose a

major. They implicitly expect their professors to

inform them of their strengths through the grades

they assign. Differential grading standards, by pro

viding misinformation, betray that expectation. The

resulting misallocation within universities has been

discussed at length here. The greater tragedy of mis

matched careers and missed callings perpetrated by this misinformation can only be imagined.

Notes

We would like to thank two referees and an associate edi

tor of this journal for helpful comments. We are deeply

indebted to Chris Auld for his input. We would also like

to thank Herb Emery, Richard Lipsey, Lasheng Yuan, and

J.F. Wen for thoughtful comments on an earlier draft. Paul

Anglin's unpublished work on grade inflation inspired our

interest in the subject. We thank Sarah Eaton and Subrata

Sarker for research assistance.

1 In this paper we raise what we think are serious and

widespread issues concerning grading practices in Cana

dian universities. Our objective is to raise the issues, not

to single out offending universities. So we prefer not to

publicly disclose the names of the three universities con

sidered in this section. We have, however, communicated

their names in confidence to this journal's editor.

2 The average grade point at the junior level has been in

creasing by 0.053 per year on a 9-point scale at University 2.

3 The average percentage of As awarded in senior-level

(junior-level) courses for University 1 is 31.6 percent

(20.3 percent). The average percentage of A+s awarded

in senior-level (junior-level) courses for University 2 is

9.6 percent (5.6 percent). For University 1, the average

grade awarded in senior-level (junior-level) courses over

the period for which we have data is 3.01 (2.68) on a 4

point scale. For University 2, the average grade in the

senior-level (junior-level) courses is 6.42 (5.14) on a 9

point scale.

4 In SOCS the relevant courses are the last 15 full courses taken, in ENG they are the last 10 full courses

taken within the ENG faculty, and in BUS they are the

last 10 full courses taken within the BUS faculty.

5 In jobs that require only high school graduates, the

pooling is even coarser. Bishop (1988) argues that em

ployers look for information only on years of schooling,

area of specialization, and certification; they do not seek

to identify competence or level of achievement (by ask

ing for transcripts or references).

6 These proportions are given by

r I e* f(aud2)da2

PM,62) = ?-*

f > f(aud2)da2 +

f' /(?? %-)dax J0 "0 u2

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Page 23: Differential Grading Standards and Student Incentives

236 B. Curtis Eaton and Mukesh Eswaran

7 This outcome would be true even if the standards

end up being identical in the Nash equilibrium, as long as there is pooling in the labour market of students from

different universities with differing standards. Using data

from high schools in Florida, Figlio and Lucas (2004) have shown empirically that higher grading standards lead to better performance in state-wide test scores. Therefore,

inferior standards do lead to worse outcomes in terms of

human capital.

8 One could use the ps that we estimated for Univer

sity 3 for this purpose. We mention this as simply an

example, since it should be possible to estimate better

adjustment factors, given full access to university data

banks.

9 In espousing this view we agree with Dickson (1984), who argues that GPAs should be standardized by disci

pline.

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