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DISCUSSION PAPER
Report No.: ARTJ 42
Education, Experience and ImperfectProcessing of information in the Adoption
of Innovations
by
Alastair jT Fischer
Research UnitAgriculture and Rural Development Department
Operational ?olicy StaffWorld Bank
June 1985
111a Vicr.-F pn4ice;z,ed h&ar' are ?6j11 wassa of the authov(s) D znd tghey oTlhd niot!-T I-aas 1rece ae raffec g thooe off th l World Bank,
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The author is a member of the Department of Economics, University
of Adelaide and a consultant to the World Bank. The World Bank does notaccept responsibility for the views expressed herein which are those of theauthor and should not be attributed to the World Bank or to its affiliatedorganizations. The findings, interpretations and conclusions are in partthe results of research supported by the Bank (RPO 672-29); they do notnecessarily represent official policy of the Bank. The designations employedand the presentation of material in this document are solely for the convenienceof the reader and do not imply the expression of any opinion whatsoever on thepart of the World Bank or its affiliates concerning the legal status of anycountry, territory, city, area or of its authorities or concerning the
delimitation of its boundaries or national affiliation.
EDJCATICN, EXPERIENCE AND IMPERFECJ PI 3ESSING O INEOMAI(N
IN E ADOPrICN OF INNOVATIONS
A.J. Fischer
I. Introduction
Before a decision-maker decides whether or not to adopt a new
production technique, he must necessarily learn of its existence and
have some idea ot its properties. In particular, a risk-neutral
decision-maker will be unlikely to adopt the technique unless he
believes that its profitability exceeds that ot the existing technique.1
It is likely that his ideas will change as he learns more about the
technique. If he adopts eventually, at same stage his ideas will change
tran "do not adopt at this point" to "adopt". If the decision-maker
were a profit maximiser and a perfect processor of information, we could
characterise the decision-making process in Bayesian terms. The
decision-maker could be assumed to have uncertain prior beliefs
regarding innovation profitability, and would collect information which
would alter his prior view, weighting his prior beliefs and new
information optimally to obtain revised (posterior) beliefs.2
Department of Econanics, University of Adelaide. This paper wasdrafted while the author was on leave at the World Bank. Mheauthor gratetully acknowledges the support of the World Bank inproviding a cata set and its analysis: and aiso wishes toacknowledye the helpful ccmments of Gershon Feder, Melissa Gibbs,Hans binswanger and bob Lindner.
1 He may, however, trial-use a technique, of whose profitability heis uncertain, in order to generate intormation which is of value initself.
2 This set of assumptions follows the same lines as the approachtaken by U'Mara (1971), Lindner et al. (1979), Stoneman (1981), and
However, psychologists have tou.C that in the laboratory, people
are not particularly good at processing information. Most people
display a range of biases and inconsistencies and adopt a number of
simplifying heuristics for judging between alternatives.3 These
simplifications scmetimes result in nonoptimal decisions being
reached. While this implies that people do not act in conformity with
Bayes Theorem, it is argued in this paper that a quasi-Bayesian
optimizing framework may still be an appropriate characterisation of
behaviour.
In the context of the assimilation of new information into prior
beliets, psychologists have made two significant discoveries. b'irstly,
people are otten tound to be conservative in their incorporation ot new
intormation, "anch'oring" at the value of their prior beliets (' cwards,
1968). (That is, people put too yreat a weight on their prior beliefs
and too little on new intormation to be efficient in terms of bayes
Theorem).
Secondly, when the quality of the information that people receov:
is low or the information not perfectly relevant to their own
circunstances, they fail to recognise the data imperfections to a large
enough degree, and therefore incorporate imperfect information into
their beliefs to too great an extent, compared with their incorporation
of error-free infonmation (Gettys et al., 1973; Trope, 1978). In
behavioural decision theory, this is known as a problem in "ocascaded" or
eeder and u'Mara (1982),
-3 Kahnenan et al. (1982) yive a yeneral introduction to the area inpsychology devoted to work in the field, known as behaviouraldecision theory. Uther reviews of, and relevant work in, thisfield are Pitz and Sachs (1984), 1inhorn and Hogarth (1981), Siovicet al. (1977), Scholz (ed.), (1983) and Wallsten (ed.), (198U).
3.
"rmuitistaye" interence (Petersen, 1973; Schum, lU8U). Thus in the real
world, since data will not usually be pertectly relevant to the
decision-maker's own circumstances, this effect operates to sane degree
in a direction opposite to that of the conservatism noted by Edwards.
These things are incorporated into a model of the adoption of an
innovation later in this paper.
In the literature on the adoption of innovatic.is, it is known that
both education and experience are important determinants of adoption
speed (Rogers, 1983). If the timing of adoption depends on beliefs
about innovation profitability, the ways in which education and
experience can affect the timing of the adoption decision are via (a)
the rate of intormation collection, (b) the manents of the prior belief
distribution, and (c) the efficiency ot processing information. There
will also be a lag between the decision to adopt and the act of
adoption, which couid also depend on education and experience, but this
last aspect is not considerred further in the model to be developed.
We argue in this paper that, among decision-makers with the same
prior beliefs and faced with the same additional information, those who
have more education and/or experience should be more efficient
information processors because they are prone to make less-serious
mistakes in processing the information. For this reason, they usually
become earlier adopters of those innovations which turn out to be
profitable. We assume that the kinds of processing errors made are the
two which have been identified above.
This paper develops a simple model of the mean beliefs about the
profitability of an innovation, o,i the assumption that the decision-
maker is risk-neutral and acts as it hle were a bayesian processor of
4.
information. we then show how this framework must be modified to
incorporate impertect processing. In particular, we show that
conservatism in incorporating new intormation is a rational response of
a decision-maker who knows tran experience that he is not a perfect
processor of intormation. We also argue that uncertainty of data
quality, along with people's response to this uncertainty, is
understandable and not necessarily inconsistent with optimising
behaviour. Hence a Bayesian-like optimising framework can be justified.
Within this framework, a number of predictions are obtained. These
predictions are measured alongside empirical work and also against a
broad range of studies conducted mainly by sociologists (Rogers,
1983). Rogers groups the tindings from some hundreds of studies into anumber of "Generalisations". The predictions of the imodel are in
agreement with the majority tindings tor all relevant Generalisations.
Betore proceeding to the model proper, we discuss the results from
psychological research and the appropriateness of usiny an optimising
tramework.
II. Putting the Psychological Findings into an Optimising Eramewrk
Given that people do not act as efficient (Bayesian) processors of
information, it may appear unclear as to how such a situation may bemodelled. If people know from experience that they are imperfect
information-processors, it is plausible that they learn fram thisknowledge, and make adjustments to their behaviour accordingly. Thus,people who adjust their behaviour in the knowledge that they are poorprocessors of information will not usually act in accordance with bayesT'heorem. In tact, scme departure fran bayes Theorem, in this second-
5.
best situation, will be optimal.
Let us take a simple example to show that it will be optimal tor
imper-ect intormation-processors to be conservative in their use ot new
information. The numbers in the example may be generalised to symbols
it it is thought that this would add to its applicability.
Suppose that a risk-neutral4 decision-maker attemnpting to maximise
profit knows from past experience that only 40 per cent of innovations
in his area of operation are suitable tc his own circumstances. If a
particular innovation is in fact suitable and he adopts it, it results
in 10 units in extra profit compared with existing practice; if
unsuitable and he adopts, it is worth (-10). In advance, without any
extra information, he does not known whether a particular innovation
will be worth (+10) or (-10).
His payoff rnatrix is given by
State of Nature
Strategy Successtul Unsuccesstul
Adopt 10 -10
Do not adopt 0 0
If he adopts all innovations, his payoff equals
10(0.4) + (-10)(0.6) = -2
4 Risk-neutrality is assumed so that only the mean value ofprofitability needs to be considered, and not its variance oruncertainty with respect to the mean. Maximising profitability isa polar assumption, and given that the decision-maker is assumed(a) to maximise and (b) not to be concerned with maximising or evenconsidering anything but profit in his utility function, then theassumption of risk neutrality is merely another simplifying device.
.- ....
6.
If he adopts none, his payoff equals 0. If he adopts half of all
innovations (necessarily at random with respect to their profitability)
his payoff is (-1). Thus, without further information (other than the
knowledye of the existence ot certain innovations), he will not adopt
any such innovations. T'he tact that the payott is negative for
innovatiny without any intormation about the innovations should not be
surprising; it is one explanation ot the otten substantial lag between a
decision-maker's time of awareness of the innovation.and his tirst use
of it.5
Let us suppose in the next period the decision-maker is in receipt
of all available new information, which now allows some, but not total,
discrimination between innovations if it is used efficiently. Suppose
that the raximum effective Luse of inforrLation allows the decision-maker
to correctly categorise 70 per cent of what would be successful
innovations as successful. He adopts these innovations-. He- wrongly
cateyorises 30 per cent ot what would be successful innovations as
unsuccesstul, anO (wronyly) does not adopt these. Conversely, of the
innovations which would be unsuccessful, he wrongly categorises 30 per
cent as successtul and adopts them. (This tiyure ot 30 per cent does
not need to coincide with the previous tigure ot 3U per cent; it is done
5 Moreover, the fact that many innovations, probably the vastmajority of them, are never widely adopted, is also consistent witha negative value of prior beliefs about innovation profitabilitygenerally. Rogers (1983, pp. 92-3), referring to the pro-innovation bias of the literature, writes "Undoubtedly, hybrid cornwas profitable for each of the Iowa farmers in the Ryan and Gross(1943) study, but most other innovations that have been studied donot have this extremely high degree of relative advantage. Manyindividuals, for their own good, should not adopt them" (italics inthe original) and (on page 74) adds: "Only 1 idea in 540 resultsin a successful new product (Marting, 1964, p. 9). Only 8 per centof the approximately 6,000 new consumer items introduced each yearhave a life expectancy of even one year (Conner, 1964)",
7.
for simplicity only). The other 70 per cent he correctly recognises as
unsuccessful and does not adopt.
The payoff from the strategy of adopting 70 per cent of successful
and 30 per cent of unsuccesstul innovations is given by
10(U.7)(U.4) + (-10)(U.3)(U.6) = +1
which is preferable to doing nothiny.
However, if on beiny given this additional information, he is
unable to process it with maximum efficiency, he may well not make a
profit by adopting. If he cannot discriminate better than 60-40 in
favour of successful innovations, and better than 40-60 against
unsuccessful ones, his payoff from adoption will be negative.
The above analysis is equivalent to the use of Bayes Theorem with
prior probability of discovering a succesc.ul innovation of 0.4,
posterior probability of G.28 - = 0.61 with optimal use of theprobaility 0.28 + 0.18
information, and posterior probability of 1/2 with only 60-40 ability to
discriminate. rhe poor information processor in this situation (less
than 60-40 discrimination) will theretore require evern more information
betore he beyins to adopt any innovation at all. It will appear to an
observer who is unaware of the processor's imperfect processiny ability
that he has been overly conservative in his use of new information.
However, the processor has been rational in the knowledge of his
shortcomings, and not simply irrational. The difference is not merely.
semantic, in that rationality in the face of shortcomings can be
modelled in an optimising framework using a modified form of Bayes
Theorem. That is, we shall assume, when modelling the process more
generally, that the poor information processor acts like an efficient
8-
information processor who has less information.
The actions of the poor information processor in the example (lessthan 60)-40 discrimination, negative payoff to adoption) may becharacterised in other ways. We could (rather perversely) assume thatthis processor could process the information efficiently (even when wekncw he really can't) and that in order to generate a negative payoff,he lowers the mean ot his prior beliets (in the example, below (-2)).This alternative, however, appears. to be less plausible and less.consistent, as there is no reason to suppose that decision-makers shouldbe consistently downwardly biased regarding the proportion of successfulinnovations in the past. However, it is of course possible (perhaps
likely) that the poor information-processor may also be a poor utiliser:of innovations, and it is this which would lead him to a lower mean ofprior beliefs about innovation profitability. It is also likely that
the variance of prior beliefs is higher for poor information
processors: scmeone who cannot utilise information well, may also havea vaguer idea of the past than an efficient user of information. Thesehypotheses also form part of the model in the tollowing section.
This picture ot the poor intormation processor will be combinedwith that of the quality ot intormation in the model. It is aryued thatinformation is otten not ot pertect relevance to the aecision-maker's
own circumstances. Learning by looking at what someone else does willnot yenerate the same-information as learning by doing.
In the case of agriculture, the information given by an extensionofficer may relate to the performance of a plant variety in soils andconditions which pertain sane distance away, and which are not the sameas those which pertain to the local farmer. In the case of a f inn
9.
deciding whether to purchase a particular piece of new equipment, theinformation given by salesmen miyht accurately describe the equipment'sperformance in a samewhat different working environment.
Such information which is available to the decision-maker forceshim to make a two-stage inference: first, he must translate theinformation, generated scmewhere else, to his cwn circumstances,
generally with an error; second, he must then use the translatedinformation to decide whether the innovation will in the long term beworthwhile. Until now, most modelling has considered only the second ofthese problems, acting as if the first does not exist. Yet in the realworld, both torms ot uncertainty will generally be present. Consistentwith the results of the behavioural decision experiments mentionedearlier, we shall assume that pertect infoni-ation processors recogniseimperfect data and allow for it in terms of the correct amount ofincreased uncertainty, but that poorer processors tend not to recognisethe imperfections, and to underestimate the increased uncertainty thatthe imperfections add. The following discussion aims to 3haC that it isunderstandable for an inexperienced person to confuse the poor qualityof the data with his own imperfect processing abilities.
Let us suppose for a moment that a decision-maker is in possessionof scme information which is of perfect relevance to him: for example,it could relate to his trial use of a new piece of equi>xnent.Nonetheless, the information will very often be fragmentary: it mayrelate only to a short time-period and only limited environmentalconditions. Unlike theoretical exercises in which the fonm of thedistribution of the likelihood function is assumed to be known, as also(sametimes) is the variance of the distribution, generally in the realworld these things do not pertain. In particular, the frequency of
occurrence of outliers is unknown in the real work with much
uncertainty, in a variety of circumstances. Thus, when there is onij a
small amount of information available, the decision-maker's lack of
knowledge of the form of the distribution of the likelihood function is
likely to substantially increase the variance of his subjective
beliefs. On the other hand, if data is available in abundance, both
memory and people's ability to do calculations are limited. Again, Lhis
adds to the uncertainty of scmeone trying to make a decision.
On top or this, very otten people have to rely on information which
is not perfectly relevant to their own circumstances. It is otten very
ditricult to know, particularly in regard to something new, the extent
to which intormation trcm a tunctionally or geographically ditterent
area can be translated to a decision-maker's own circumstances. When a
decision-maker reviews the past, therefore, he often will not know
whether an error of judgment which he has made has been due to his poor
processing of perfectly relevant information, or the poor quality of the
infonmation itself. Those with experience of translating information
for related innovations may know better what allowances to make for this
first stage -¢ inference, but those without such experience, who do not
know how to distinguish between the error of sampling perfectly-relevant
information fram that of translatin,g imperfect infonmation, are more
likely to lump such errors together. However, while the error of
samlpling perfectly-relevant inrormation decLines with increasing sample
size, that ot translating it trcm another source often will not decline
with increasing sample size. As sample size increases, theretore, an
inexperienced decision-maker who has lumped the two errors together will
tend to decrease the error of imperfect information too much. He will
be misled by continuing (but essentially irrelevant) reports of the
protitability ot the innovation in circumstances clitterent tran his own.
To canplete the discussion regarding the link between education and
experience, and the speed of adoption, it is noted that we would expect
that each piece of information is worth more to an eff icient processor
of information, still in the process of evaluation of alternatives, than
is the corresponding piece of information to an inefficient processor.
Thus, since the information is likely to have higher marginal value to
an efficient user of it, such users will seek information sooner, and so
adopt protitable innovations sooner. This will not be universally true,
of course: tor example, once an erficient user ot information has made
a detinite decision to adopt, or alternatively, not to adopt (rather
than still be in the evaluative process), information gained beyond this
point ot time may be ot very little value. Inetficient users yet to
make a decision will yive this intormation more value. It will also be
untrue of intormation of little or no relevance: the etticient utiliser
will (by definition) recognise this and will not place much value on it.
There may also be other personal characteristics of decision-makers
which determine their speed of information-gathering and processing
ability. These may be incorporated into the framework proposed in the
model in the next section if so desired, but to do so in present
circumstances would add little to understanding for the price of rather
more lengthy algebra.
III. The Model
We assume that a decision-maker's prior knowledge ot the perceived
mean profitability of the application of the innovation (per unit of a
tixed resource) is given by6 N(yo, i ). we also assume that new
intornmation about innovation protitability is received in discrete
units, so that it can be sampled as the independently-distributed randcm
variable X - N(p, a where normality is again assumed for
convenience. p is assumed to be unknown to the decision-maker, but
(since the innovation is assumed to be profitable) p > a, where a is the
known mean of the existing technique. As for the example, a > yo. We
assume that y , 52 and a2 are known, and that the decision-maker is
risk-neutral.
In this formulation, X is assumed to be of perfect relevance to the
decision-maker, and to be generated as X. = + sit where co D N(0, a
h(£ i£3) = 0. It the decision-maker is also a pertect intormation
processor, the mean value ot the decision-maker's beliets regarding 1.,
given a sample ot m pieces ot intormation, will be yiven by bayes
Theorem as
6 The distribution N(y0, 62) may be seen as a sort of generalisationof the discrete prior distribution in the example in Section II,with normality imposed. The example had values (-10, 10) withprobabilities (0.6, 0.4) respectively; its mean is -2 and itsvariance is 96, given that the values and probabilities are knownwith certainty. These values (-2, 96) characterise the first twomcmnerts of the prior distribution of the mean of a sample of oneinnovation. More yenerally, when the prior may take many possiblevalues, and not just two of them, and when their orobabilities areUncertain, the distribution of the prior perceived mean ofprofitability can be given by N(y , 62), where normality is assumedfor convenience. A significant difference between the model inthis section and the numerical example in the last section is thatthe model in this section deals only with an innovation which weknow is to be successful. In order to yet the result in theexample it was necessary to postulate innovations of which aportion are unsuccesstul. The proposition which is illustrated bythe example is then used in the model ot this section as anassumption: decision-makers act as if they were using a moditieaBayes Theorem in an attempt to optimise returns.
13.
YO XMyo~m
60 a,/m -m
Y where X = Xim 1
6c a/rn0
=y + (1 ) Xm, say. (1)
If X is generated from a single source of imperfect relevance to the
decision-maker, such that
Xi + B + ei, where si - N(O, a )2 E(eiej) = 0
and 7 where B - N((, a2 2 E(eiB) = °
in this case, Y will be given by
y
o 2 26 a /m + a
m 162 +2 ;260 a/m+al+a13
This again assumes perfect information processing.
2Note that the magnitude of a will depend on how relevant the
decision-maker perceives the information fran an imperfect source to
be. If the source is close geographically in the case of agriculture,
2or close functionally in the case of an industrial firm, a will be
smal2L otherwise it may be large. More information fran the single
source will reduce the effect of a in equation (2) but not that of
7 B has been given a mean of U without loss of generality. Should anonzero mean for b be chosen, we may define a new j' and B', whereB' has zero mean, and the mean of B has been absorbed into .', withsimilar properties to p.
14.
aB e The eftect of ab will decline in (2) it a new source of
information is tapped, which is either "close" to the decision-maker
(geographically or tunctionally) or it the new source is not completely
correlated with the original source.
Finally, we introduce the ettect ot ditterent i.nformation-
processing skills (into-skills tor short). Let k = into-skill, where k
depends on experience and education (and probably other personal
variables as well - but these latter are ignored).
Fran the discussion in Section II, we assume the following
regarding the components of equation (2).
2 2(a) m = a
wlhere m(k) has the tollowing properties: m(0) 0, m(X) = m, m'(k)
> U, m'(k) < U.
FIGURES l(a) and 1 (b)
(,-gh) B.
m(U) 0 implies that those with zero info-skill cannot
assimilate any information at all: they act only by
innate prior beLiefs or instinct.
15.
m(X) - m: those witih much education and experience can process
all new information efficiently. (This formulation also
captures the assumption that those with more into-skill
actually gather more information at a given time, as well
as being capable of using it more efficiently).
See Figure l(a) for the relationship between m(k) and k.
(b) a2 = C2(k)
2where a(aB)/ak -aB > 0; aEB < 0.
This implies that those with greater info-skill recognise
imperfections in information more efficiently. The relationshipbetween a2(k) and k is shown in Figure l(b).
() 52 2(c) 60 =do(k),
a 62(k)where 0k - 6' < U, and d" > U.ak
Peowle with more info-skill have samewhat less vague priors
based on experience.
(d) y = y (k)
a yo(k)where ak y > O.
Those with more info-skill have also had better experiencewith innovations (on average) in the past than those without.
16.
The model now beccnes
'Yo (k )i
do(k) a2 /m(k)4+ a:(k)Ym(8,k) =- - ( 3)
2 2-d0(k) a /m(k) + a (k)
since the decision-maker (being risk-neutral) will adouL the innovation
as soon as ym(8,k) exceeds , we see that the speed ot adoption depends
on how soon y (ii,k) (called simply y hereafter) reaches a. In turn,
adoption speed depends on how tast ym is growing. we wish to find out
how y responds to changes in k, the level of education ard experience.
2Putting - + a2 + 62 = A, we obtain, replacing Xm by )i for
simplicity,
ay O (m + ) aym ( y) 622a2 2 an2 20A M A
aym ( 2 2 2 = aand a m a /m___Ii 0
and soay (t3,k) - y iam ay aa2 ay a62 ayay-
M M am + M aM a=k = am 2 aak Caa3 ad 0
0a 2
22 + ( ( 2)6] +2 ½ (k) + - a+ ((+) 0+ --)- (+) -
(4)
17.
In (4), ignoring for the mcment the last term in square brackets, we see
that ay is conposed of two terms of opposite signs within the brackets
and a positive term, probably small, outside of them. When information2is perfectly relevant (i.e., when a2 = 0) the middle term in square
brackets disappears and - > 0. Thus, when information is perfectly
relevant, those who are info-skilled will be the tirst to adcpt the
innovation. The only exception likely here is where the third term in
square brackets is important: this would be where more inf&-skilled
people were relatively-more dogmatic in their beliefs that i nnovations
were unprofitable, presumably from some bad past experience. In this
case it may require an unskilled information processor, mindless of his
peers, to begin the adoption process.
On the other hand, when both m and aB are large (that is, there is
a lot of information, but all of it fran scme distant geographic or
functional area), the first term in square brackets becomesay
insignificant and if the final term is small, -m- < 0. That is, when
there is a lot of intormation, all of dubious quality, the most info-
skilled will not be the first to adopt, as they have correctly noted
that a is large, and have properly discounted the low quality
information. However, those not so skilled are (in the nodel) inclined
to treat information of whatever quality in much the s&-ne way, so that
should anyone adopt the innovation, it will be saneone trom among those
who are not the best information processors. once the performance of
ahhis innovation has been observed by others belonging to the same
functional or geographic area as the maverick earliest adopter, however,
tFli value for a2 will fall, and if the innovation performs well in the
nore relevant circumstances, it will be adopted more generally, the
initial adoption being followed by those who are most skilled in
information gathering and processing.
If the final term is large, however, it is possible that this term
may dcaninate. This would say that decision-makers with less education
and experience, having learned that innovations have not been as
profitable tor them as for others with more education and experience,
are so "pessiXnistic" as a result, that they will not be the tirst to
innovate, despite the encouraging signals (tram near and/or tar) which
try to entice them with samething else that is new.
IV. E&irical Results
Can the time lag between the appearance of the innovation on the
market and its adoption by decision-makers be explained by their
different infonmation processing abilities, and in particular, by their
education and experience? We note that this lag should be inversely
related (as a linear transformation) to ym(B,k), the perceived
profitability of the innovation compared with that of the existing
technique.
The time to adoption (TIMALXPT) will therefore be a function both
of prior beliefs of protitability (at time of awareness) together with
the content ot the information obtained subsequently, modified by
differing processing abilities. We shall call the information modified
by processing ability, the "perceived-intonmation" ot the processor.
Fran the model of Section III, the mean of prior beliefs (y0), the
variance of prior beliefs (3 ) and the variance of perceived-information2 0+ a2) are determined by education and experience, as well as by a
hfamber of other variables.
Thus,
y (k) PRIuMEAN = f1 (EDUJCAT, EXPER, OTHER) (5)
19.
62(k) 2 PRIORVAR = f2 (EDUCAT, EXPER, OTHER) (6)
2 INFOMEAN = f3 (OTHER) (7)
+ a(k) - INFOVAR - f (EDUCAT, EXPER, OTHER) (8)
k'ran this,
TIMALXJP =( () = y (PRIUME:AN, PRIORVAR, INVOMEAN, INtUVAR)
= y (EDUCAT, EXPER, OrHER) (9)
The effect of education and experience on the mean and variance of
prior beliefs may be tested fran equations (5) and (6), if prior mean
and variance can be measured. We have attempted to do this for a sample
of South Australian farmers. These farmers were interviewed about some
potential innovations, including elicitation of the mean and variance of
their beliefs about innovation profitability soon after their awareness
of them. There are two problems surrounding the elicitation of prior
beliefs. one is that the elicitation process itself may be faulty:
what farmers say their beliefs are, may not be what they really
believe. Different elicitation methods in such circumstances may lead
to different statements of befiets. Second, additional information
usually acccmpanies the announcement of a new process or technique.
Farmers will not usually receive exactly the same additional information
at this time, but even if they do, their own differing circumstances
will be such that they will interpret the information differently so
that the prior beliefs at time of awareness will inevitably containvarying (nonzero) amounts of specific information about the innovation.
20.
Unfortunately, the elicitation of prior beliefs has provedexceedingly difficult. At this stage, no worthwhile relationships
between prior beliefs and processing abilities have been found, but itis clear that whether an underlying relationship existed or not, theelicitation process has given answers for individual farmers which have
been internally inconsistent and so overconfident (in terms of lowvariance of Prior beliefs) as to render the particular data meaningless
for the task of finding a relationship. Since the links betweeneducation and experience on the one hand, and prior mean and priorvariance on the other, are likely to be tenuous, for this paper it isassumed that no such relationship exists, and that in equation (9),education and experience effect TIMAD though their effects on processing
skills (i.e., through INEOVAR in the unobservable equation (8)), and notindirectly via prior beliefs.
That is, in our model in the previous section, we assume that thelast terni in square brackets in (4) and the term outside of them, aresmall or insignficant. Since the system of equations is recursive, it
is appropriate to use O.LL.S to estimate (9) (see Pindyck and Rubinfeld,
Chapter 11). Some indirect evidence of the additional value ofeducation and experience between the tilm of awareness and the time ofadoption has been obtained tram a data set of wheat farmers in Haryana
State, India. F'or the most part, the results of this data set confirmthe model's predictions.
Idi 1983, a. sample of 323 farmers tran Karnal district and a sample
of 569 farmers fran Jind district were asked (i) whether they had heardabut 10 different techniques, and (ii) whether they had adopted them,within the last three years, or more than three years ago. For three ofthe techniques in both districts, knowledge and adoption were almost
ccmplete, so no meaningful analysis to distinguish adopters frannonadopters was possible. Of the remaining seven techniques, a logit
regression was run separately for Karnal and Jind farmers, giving 14
equations in all for both time of awareness and time of adop.tion. Since
one of these techniques (zinc sulphate) had not diffused in Jind to a
great -nough extent, the logit regression did not have enough
observations to be meaningful, and only 13 equations converged and were
estimable. The two sets of loyit regressions had dependent variables,
respectively, of TIMDWUPT taking the value of 1 if the farmer adopted
more than three years ayo, U otherwise; and TIMAWAMIs, takiny the value
ot 1 if the farmer was aware of the technique more than three years ago,
U otherwise. F'or all regressions, there were nine independent
variables, four related to education and experience and five related to
other factors.
The four variables related to education and experience were:
EDUAGR: Binary variable equal to 1 if the farmer had ever
participated in any short-term training in agriculture.
EIDUHEAD: The number of years of schooling of the head of the
household.
LNAGE: Loyarithm of age of the tarmer.
M1M5GUVT: binary variable equal to 1 if the farmer hol-ds a
position in village government, cooperative society or
block committee. (This variable is likely to be related
to status and respect and not necessarily reflect either
education or experience, though it has been used as a
proxy for the latter two variables in this instance).
The signs on these variables could be expected to be positive.Alternative regressions in which EDU(HEAD was replaced by a variablerelating to the number of years of schooling of the most educated memberof the household gave similar results, and are not included. The othervariables included in the regressions were:
CASTE: Equal to 1 if the farmer is a Jat.
CREDIT: Equals 1 if the farmer is likely to have a credit problem.IRRIG: Equals 1 if the farmer uses irriyation.
LNOPLAND: Logarithn of land operated.
TENANT: Equals 1 if tne tarmer rents 10% or more of operated land.
*T'heir expected signs were: CASTE - no preconceived ideas, CREDITnegative, IRRIG - positive., LNOPLAND - positive, ThNANT - probablynegative.
The results of the logit regressions are sunmarised in thefollowing table, which shows the number of regressions in which thecoefficients of each variable are positive and the number which arenegative, tie number of times that the t value is greater than 2 inabsolute value, the number of times between 1.5 and 2, ancl thearithmetic average t value over the 13 equatins.
At this stage, scinething should be said about the use of theaverage value of t. There was a high degree of concurrence betweEn theanswers yiven by any one farmer to the questions about the seventechniques: it a farmer said he was aware of one technique more than 3years previously., it was likely that he would be aware of each of theother techniques more than 3 years previously, and similarly foradoption. Conversely, if a farmer said he was unaware of one technique,
23.
Aipticn AwarensSs
Variable S. d! Ties Significance NO. of Ti1es S4ificance
b3 (-) jtj>2 1.5<ltl<2 Ave t (+) (-) Itt>2 1.5Cltl<2 Ame t
CASTE 5 8 l-1l* 1,-2 -0.3 2 11 1,-4 1r-l -1.1
CREDIT 4 9 1 1 0.1 5 8 1,-1 1 -0.1
ECXAPR 5 8 -1 -2 -0.6 2 11 -2 -1 -0.9
EtJHEAD 12 1 3 2 1.0 10 3 1 1 0.6
IRRIG 11 2 5 2 2.3 10 3 5 1 2.0
LNXE 11 2 0 2 0.8 11. 2 1 1 0.7
LNZIPLAND 4 9 1,-i 1'-i -0.4 4 9 2,-i 0 -0.1
MihPE83 13 ( 5 2 1.7 13 0 5 1 1.7
T.NANr 6 7 1 2 0.3 7 6 1 2 0.3
* Ihis denotes that t > 2 on one occasion and t < -2 on one occasion outot the 13 regressions.
it was relatively irore likely he would give the same answer for each of
the other techniques. Thus for Karnal, the 7 equations for adoption
mostly had similar magnitudes for the t values for each variable, as did
those for awareness. Ditto for Jind, but with 6 equations. Thus, for
Karnal, there are not as many as 7 independent t-values for each
variable, but the equivalent of more than one. For the thirteen
equations taken t?ogether, those from Jind are independent of those for
Karnal, so that there are in excess of two independent t values. The
average value of t is used as a summary measure, because apart from
IRRIG, the t-values tor Jind and Karnal did not differ a great deal from
the average, either within areas or between.
In detail, we aeal firstly with the time of adoption. Results for
Karnal and Jind were similar overall, except for IRRIG, because in
24.
Karnal almost all farms were irrigated, and there were not enough
nenirrigated observations to give a signif icant results t values for
this variable were small and erratic for Karnal, but were high and
positive for Jind, where a large minority of farms did not use
irrigation. If caste had an effect, the effect differed in sign for
different practices in both Karnal and Jind; overall, therefore, caste
had no pervasive effect in a single direction. Credit constraints,
amount --f land operated and renting land were not significant overall,
leaving the four variables most closely related to education or
experience. Of these, MEMBGOVr was the most important explanator of the
time of adoption, all thirteen regressions shcwing the expected sign,
and an average t-value of 1.7, of similar magnitude in both Jind and
Karnal. Since tarmers who have adopted one technique are very likely to
have adopted others, it cannot be argued that the MEMI3GOVT coefficient
in either Jind or Karnal, over the 6 or 7 equations taken together, is
necessarily significant. However, since the set of seven Karnal
equations is independent of the six Jind equations, high t-values for
both areas, taken together, makes MEMBGOVT a significant variable
overall (the probability that two independent observations of t are both
greater than 1.7 is .002). EDUHEAD is probably also significant overall
(the probability that two independent observations of t are both greater
than unity is .025), although the effect is not as strong as that of
MEMBGOVr. LNAGE may also be significant, though the effect is weaker
again (the probability that two independent observations of t are both
greater L,.an 0.8 is .049). EDlUAGR, on the other hand, is in the wrong
direction, and may be significantly so, its etFect being a little less
than that of LNAGE in tenns of absolute t-values (the probability thattwo independent observations of t are both less than -U.6 is U075). If
this result is significant, it is possible either. that short
25.
agricultural courses are a waste of time and money, or that courses were
designed primarily for the least-torward looking tarmers, or tor tarmers
frau the most backward villages.
Therefore, tor explaining the time of adoption, after allowing for
variables as diverse as farm size, credit constraints, tenure, caste and
irrigation (of which onl.y irrigation was important) it is found that,
taken together, education and experience variables play a significant
role in the predicted direction.
We now turn to the time of awareness. Basically the same results
still apply for the variables not concerned with education and
experience. The results suggest, though not very strongly, that
education and experience are not as important in determining time of
awareness as they ara for time of adoption, for the following reasons.
In the first place, EDUHEAD has the expected sign less often, is
significant less often, and has a lower average t-value for awareness
than it had tor adoption. Next, LNA(.E has a marginally lower average t-
value for awareness than for adoption; next, EDUAGR has the expected
sign in only 2 out of 13 equations tor awareness ccmpared with 5 out of
13 for adoption, and an average t-value of -0.9 rather than -0.6.
Finally, the average explanatory power of the regretsions is not as
great for awareness as for adoption. The 13 logit regressions for
adoption correctly categorize on average 67 per cent of cases, ranging
fram 57 per cent for sowing depth in Karnal to 85 per cent for
application of potash in Jind, whilp the same regressions for awareness
as dependent variable explain 65 per cent of cases overall, ranging frcm
5S per cent for potash in Karnal to 82 per cent for potash in Jind.
None of these pieces of evidence is individually very strong, .. in
total they suyyest that education and experience, inasmuch as they are
26.
less of a detenminant of the time of awareness than the time of
adoption, help farmers to process information in reaching a decision to
adopt. This explanation, however, does not rule out the possibility
that education and experience influence farmers' prior beliefs and their
rate of information collection along with the influence on processing-
ability. The implication from the regression which suggests that
TIMMARE is related to education and experience (as postulated) is that
in the early stages of information collection, the more educated and
experienced farmers collect information at a faster rate.
The model's predictions are also consistent with the general tenor
of the sociological literature on innovation diffusion, as given by the
following "Generalisations" due to Rogers (1983). The number of studies
(supporting, not supporting) of the Generalisation are included in
parentheses in each case.
(1) Earlier knowers of an innovation:
(a) have more education than later knowers (17-7).
(b) have more exposure to all forms of communication: mass media
(18-11), interpersonal channels (16-2), change agent contact
(13-3), social participation (11-2) and cosmopoliteness (5-O))
(2) JMass media channels are relatively more imaportant at the awareness
stage, and interpersonal channels are relatively more important at
the persuasion stage (18-2).
(3) Mass media channels are relatively more important than
interpersonal channels for earlier adopters than for later adopters
(8-2) .
27.
(4) Cosmpolite channels are relatively more important than localite
channels for earlier adopters than wor later adopters (9-0).
(Note: Generalisations 2, 3 and 4 are broadly consistent with the
theory of Section II on the quality of information, "interpersonal"
and "localite" channels being regarded as "higher quality").
(5) The rate of awareness is more rapid than the rate of adoption
(2-0); earlier adopters have a shorter awareness to adoption lag
than later adopters (5-1).
(Note: This is consistent with the mnore "innovative" tarmers
those with more education and experience, ceteris paribus - seeking
information faster and evaluating it faster.)
(6) The relative advantage of an innovation, as perceived by members of
a social system, is positively related to its rate of adoption
(29-14).
(Note: In our admittedly narrow context, (. - a)r the relative
profitability of the innovation, is our measure of "relative
advantage".)
(7) Earlier adopters have:
(a) more years of education (203-72)
(b) greater literacy (24-14)
(c) a yreater ability to deal with abstractions (5-3)
(d) yreater rationality (use of the most effective means to reach a
given end) (11-3)
(e) greater intelligence (5-0)
(f) more favourable attitude to change (43-14)
(g) more exposure to all forms of mass ccmmunication: mass media
(80-21); interpersonal channels (46-14); change agent contact
(135-21); social participation (109-40); cosmpoliteness (132-42)
28.
(h) greater khowledge (61-19)
(W) seek more information (12-2).
(Note: Generalisation (7) (f) is as close as Rcgers' Generalisa-
tions go towards discussion of what we have labelled "prior
beliefs").
All 25 yeneralisations above show a majority ot stuaies consistent withthe predictions ot the model.
V. Discussion and 11EEar
This paper integrates several major findings by behavioural
decision psychologists into a business decision model, the development
of which has been mainly within the economics discipline. It shows thatcertain aspects of the behaviour of people who make decisions underuncertainty can, in qualitative terms, be captured by a model whichallows them to be poor processors of information. The model stayswithin the mainstream of econcnics by assuning that decision-makers areattempting to optimize returns, subject to the constraint of being
imperfect intormation processors. The conclusion reached by means of anexample is that poor intormation processors who are aware of theirlimitations will act as if they were using Bayes Ttheorem, but utilizing
a smaller quantity of intormation than is actually available to them.This conclusion has also been reached empirically in experiments done by
behavioural decision psychologists. A defense is therefore provided ofthe use of an optimizing framework and of a modified form of BayesTheorem to describe the actions of decision-makers when they adapt tonew circumstances in their environment.
29.
One criticism of the paper is that the analysis, particularly inSection II, is not rigorous. However, given that it is not really knownhow it is that scme people make better decisions than others when giventhe same information, a more rigorous approach is probably not
justified.
Another criticism that could be leveled at the approach is that thereasoning could be circular. It could be sugyested that if we observesomeone departing tram bayes Theorem even more than usual, we simplycall him an even poorer information-processor who nevertheless is stilloptimizing, rather than admit that neither an optimizing tramework norbayes Theorem are appropriate descriptions of his behaviour. Tb some
degree this criticism may have validity, to the extent that the
distinction between "departures from Bayes Theorem" and "poorinformation-processor" has not been drawn out. However, the framework
oi the paper is useful in that it does predict conservative behaviour inthe incorporation of new infonmation, which is also the experimentallyobserved result; this cannot be the result of circularity in reasoning,as the prediction could have been in the other direction. Thecircularity arises from not being able to predict independently theextent ot the conservatism. beyond this, the optimizing model has givenrise to other predictions which also are in the same direction asbeiLaviour observed in the real world. The weakness ot the model is that
inlik,- the unmodified 8ayes Theorem, which gives exact predictions, wecan nOw do 1no wore than state the direction of changes.
Cn ths second strand xdken fran behavioural decision theory, thecascading of inferences (or in the language of this paper, the qualityof information) the results of behaviour observed in the laboratory havebeen taken as given, with the suggestion that it is likely that people
30.
confuse the quality of information and the quality of information-
processing. To paraphrase the earlier discussion about this, using the
symbols of the model used in Section III, when m pieces of imperfect
information are available frcm the single source, the actual variance of2 2
estimated mean profitability, R., is given by m- + a2. It would e easya + anfor an inexperienced decision-maker to act as if this were
mexcept that this will understate variance, especially if a2 is large
Bccmpared with a2. To avoid this, someone with general experience, but
no, expexience specif'ic to the innovation, may mocify the variance toaF + a
*- m* , where m* < m, to compensate for the underestimation. The
formulation in the model is a yeneralised tomn ot the last expression.
The formal model used in Section III goes one step further back,
and suggests that decision-makers' personal characteristics such as
experience and education should affect the rate of information-
gathering, prior beliefs about innovation profitability, and
information-processing skills. Given the kinds of deviation from
perfect information-processing described above, it is suggested that
better information gatherers and processors (those with more education
and experience) will deviate less from perfect information-processing
(i.e., fran Bayes Theorem) than will poor processors.
The prediction from the- model is that, tor the most part, these
factors make better-educated and experienced decis-mn-makers earlier
adopters ot innovations which turn out to be profitable. The main
exceptions are where the only information available (of which there may
be a lot) is fram a distant geographic or functional area believed to be
of marginal relevance to decision-makers, or in those places where most
decision-makers are dogmatic in their beliefs that innovations are never
profitable. In the former case; it will pay the best-informed to wait
until scieone close to them (and with less experience) who has mistaken
the poor-quality information for that of higher-quality decides to
adopt. The best-informed will follow suit only when it is clearer that
the innovation will in fact be profitable. In the latter case, the
"best-informed18 , who are dogmatic about all innovations being
unprofitable, are in fact wrong.
A criticisn of this part of the model is that it is assumed that
the "mistakes" which info-skilled decision-makers are better at avoiding
are those that the behavioural decision psychologists have identified
and are included in this model (or at least, which operate in the same
direction as those identified torms ot error). It is possible that
skill in intormation processing is determined in the main by other
factors, and that the identified shortcomings modelled here are not very
important. This aspect cannot be answered in this paper, as it depends
on behavioural decision experiments, few of which are likely to have
been done.
That a number of predictions of this model are shown to be in
qualitative agreement with a range of studies in the adoption of
innovations indicates utility in integrating psychological and economic
approaches. It is likely that further work in this area, as well as in
the wider areas of beliefs, anticipations, adjustments and forecasts,
will also benefit fram a closer relationship of these disciplines. More
general incorporation into economic models at findings about the way
people actually behave rather than how they "ought" to behave should
lead to better models and predictions.
,.
32.
RFERENCES
Conner, J.Te, (1964), "Progress Reshapes Canpetition", Printers' Ink,
Edwards, We, (1968), "Conservatisw in Human Information Processing", in B&Kleinmuntz (ed.), Fornal Representations of Human Judgment, NewYork: Wiley, 17-52.
Einhorn, H.J. and R.M. Hogarth, (1981), "Behavioral Decision Theory-Processes of Judgment and Choice", Annual Rev. Psychology, 32?53-88.
Feder, G. and G.T. O'Mara, (1982), "On Information and Innovation,Diffussion: A Bayesian Approach", Pmerican Journal ofAgricultural Economics, 64, 145-147.
Gettys, C.F., Kelly, C. III and C.R. Peterson, (1973), "The best-GuessHypothesis in Multistage Inference", urganisational behavior andHuman Pertormance, 10, 3b4-373.
Kahneman, D., Slovic, P. and A. Tversky, (1982), Judgment UnderUncertainty: Heuristics and Biases, Cambridge University Press.
Lindner, R., Fischer, A. and P. Pardey, (1979), "The Time to Adoption",Economic Letters, 2, 187-190.
Marting, E., (1964), New Products, New Profits, New York. AmericanManagement Associates.
O'Mara, G., (1971), "A Decision-Theoretic View of Microeconcmics ofTechnique Diffusion in a Developing Country", (unpublished Ph.DOThesis, Stanford University).
Peterson, C.R. (ed.), (1973), "Special Issue: Cascaded Inference",organisational Behavior and Human Performance, 10, 315 onwards.
Pindyck, R.S. and D.L. Rubinfeld, (1981), Econometric Models and EconomicEorecasts, (2nd edition), McGraw-Hill.
Pitz, G,.F. and J. Sachs, (1984), "Judgment and Decision: Theory andApplication", Annual Rev. Psychology, 35, 139-163.
Rogers, E.M., (1983), Dittusion of Innovations, (3rd edition), New York:I`ree Press/MacMillan.
Scholz, R.W. (ed.), (1983), Decision-Making Under Uncertainty, ElsevierScience Publishers B.V., (North Holland).
Sc4un, D., (1980), "Current Developnents in Research on Cascaded InferenceProcesses", in T. Wallsten (ed.), Cognitive Processes in Choiceand Decision Behaviour, New Jersey: Erlbaum.
Slovic, P., Fischhoff, B. and S. Lichtenstein, (1977), "BehavioralDecision Theory", Annual Rev. Psychology, 28, 1-39.
33.
Stoneman, P., (1981), "Intra-FiLim Ditfusion, Bayesian Learning andProfitability", Econcnic Journal, 91, 375-388.
Wallsten, T. (ed.), (1980), Cojnitive Processes in Choice and Decisionbehavior, New Jersey: Laurence ErlbaLn.
DtzcSCUSSN ?A?E?.SAGR/Research Uni t
Reoort 'No. ARU IAgricultural Mechanization: A Comparative Historical Perspective
by Hans P. Binswanger, October 30, 1982.
Report No.: ARU 2The Acquisition of Information and the Adoption of New Technology
by Gershoni Fader and Roger Slade, September 1982.
Report No.: ARU 3Selectelkng Contact Farmers for Agricultural Extension: The Training and,
Visit System in Haryana, Indiaby Gershon Feder and Roger Slade, August 1982.
Report No. : ARU 4The Impact of Attitudes Toward Risk on Agricultural Decisions in Rural
India.by Hans P. Binswanger, Dayanatha Jha, T. Balaramaiah and Donald A. SillersMay 1982.
Report No.: ARU 5Behavioral and Material Determinants of Production Relations in Agricultureby Hans P. Binswanger and Mark R. Rosenzweig, June 1982, Revised 10/5/83.
Recort No.: ARRU 6The Demand for Food and Foodgrain Quality in India
by Hans P. Binswanger, Jaime B. Quizon and Gurushri Swamy, November 1982.
Recort No.: ARU 7Policy Implications of Research on Energy Intake and Activity Levels with
Reference to the Debate of che Energy Adequacy of Existing Diets inDevelopment Countriesby Shlomo Reutlinger, May 1983.
Reoort No.: ARU 8"fore Effective Aid to the World's Poor and Hungry: A Fresh Look at
Uniced States Public Law 480, Title II Food Aidby Shlamo Reutlinger, June 1983.
Renort No.: ARL 9Factor Gains and Losses in the Indian Semi-Arid Tropics:
A Didactic Approach to Modeling the Agricultural Sectorby Jaime B. Quizon and Hans °. Binswanger, Sepcem.ber L983, Revised May 1984.
teoart No.: ARU 10The Distribucion of lacome in India's Northern Wheat Region
by Jaime B. Quizon, Hans P. Binswanger and Devendra Gupta, Auxusc 1993.Revised June 1984.
Report No.: ARU 11Population Density, Farming Intensity, Patterns of Labor-Use and Mechanization
by Prabhu L. Pingali and Hans P. Binswanger, September 1983.
Reoort No.: ARU 12The Nutritional Impact of Food Aidi Criteria for the Selection of
Cost-Effective Foodsby Shlomo Reuclinger and Judit Katona-Apte, September 1983.
Oiscussion Papers (Cont'd.)
Report Yo.: ARU 13Project Food Aid and Equitable Growth: rtncom*e-T:ansfer Efficiency First!by Shlomo Reutlirger, August 1983.
er No. .RU 14lutritional Lmpact of Agricultural Projects: A Conceptual, Framework forModifying the Design and Implementation of Proj ects
by Shlomo ReuClinger, August 2, 1983.
Report Mo,: ARU 15Pacterns of Agricultural Protection by H{ans P. Sinswanger and Pasquale L.Scandizzo, .ovember 1l, 1983.
Report No.: ARU 16Factor Costs, racome and Supply Shares in tndian Agriculture
by Uanjan Pal and Jaime Quizon,, December 1983.
Reoort No.: ARU 17Behaviaral and Material Decerminants of Production Relations in Land Abundant
t.r3oical Agricultureby Hans P. Binswanger and John Mcrnaire, January 1984.
Report NJo.: ARU 18The Relatioa 3etween Far= Size and Farm Productivicy: The Role of Family
Labor, Supervision and Credit Conscraints*by Gershon Feder, December 1.983.
Revort No. : A.RU 19.A Comparacive Analysis oe Some Aspects of the Trai.aing and Visic System ofAgricultural Extension Lai India
by Gershon Feder and Roger Slade, F.ebruary 1984.
Reort No.: ART 2 0Distributional Consequences of Alternative Food Policies in Indiaby Hans P. Binswanger and Jaime B. Quizon, August 31, 1984.
Report .o.: ARU 21Income Distribution in India: The Impact of Policies and Growth in the AgricuutaalSector, by Jaime B: Quizon and Hans P. Binswanger, November 1984.
Report NTo.: 4RL ?22Population Density and Agricultural Intensification: A Study of the Evolution oQTechnologies in Tropical Agriculture, by Prabhu L. Pingali and Hans P. BinswangeK,October 17, 1984.
Report No.: ARU 23The EvoLution of Farmining Systems and Agricultural Technology in Sub-Saharan Africa,by Hans P. Binswanger and Prabhu L. Pingali, October 1984.
N .: ARU 24Poplaton ensty nd armng ystMs - The Clzanaing Locus of Innovations andTechnical Change, by Prabhu L. Pingali and Hans', Binswanger, October 1984.
,epor No.: G eH25TheTrinig nd Visit Extension System: An Analysis of Operations andffects, bY G. Feder, R.H. Slade and A.K. Sundaram, November 1984.
Reprt o.:ARU 26Tne Role of Public Policy in the Diffusion of New Agricultural Technology,
by Gershon Feder and Roger Slade, October 1984.
Report : ARU 2Fertilizer Subsidies: A Review of Policy Issues with Special Emphasison Western Africa, by Haim Shalit and Hans P. Binawanger, November 1984.
Repo,rt No.: ARU 28From Land-Abundance to Land-Scarcity: The Effects of Population Growthon Production Relations in Agrarian Economies, by Mark R. Rosenzweig,Hans P. Binswanger, and John Mecncire, November 1984.
Report No.: ARU 29The Impact of Rural Electrification and Infraseructure on Agricultural
Changes in India, 1966-1980, by Douglas F. Barnes and Hans P. Binswanger,December 1984.
Report No.: ARU 30Public Tractor Hire and Equipment Hire Schemes in Developing Countries
(with Special Emphasis on Africa). A 3tudy prepared by the OverseasDivision, National Institute of Agricultural Engineering (OD/NIAE), byP.J. Seager and R.S. Fieldson, November 1984.
Report No.: ARU 31Evaluating Research System Performance and Targeting Research in LandAbundant Areas of Sub-Saharan Africa, by Hans P. Binswanger, January 1985.
Report No.: ARU 32On the Provision of Extension Services in Third World Agriculture, byAlastair J. Fischer (Consultant), January 1985.
Report No.: ARU 33An Economic Appraisal of Withdrawing Fertilizer Subsidies in India, by
Jaime B. Quizon, April 1985.
Report No.: AR7 34The Impact of Agricultural Extension: A Case Study of the Training and VisitMethod (T&V) in Haryana, India, Gershon Feder, Lawrence J. Lau andE;rger H. Slade, March 1985.
Report No.: ARU 35Managing Water Managers: Deterring Expropriation, or, Equity as a Control
Mechanism, by Robert Wade, April 1985.
Report No.: ARU 36Common Property Resource Management in South Indian Villages, by RobertWade, April 1985.
Report No.: ARU 37On the Sociology of Irrigation: How de we Know the Truth about Canal Performance?
by Robert Wade, May 1985.
Report No.:, ARU 38Some Organizations concerned with Animal Traction Research and Development
in Sub-Saharan Africa, by Paul Starkey, April 1985.
Raeort No.: ARU 39The Economic Consequences of an Open Trade Policy for Rice in India,
by Jaim Quizon and Jaes Barbieri, June 1985e
Report No.: ARUY 49,Agricultural Mechanization and the Evolution of Farming Systems in
Sub-Saharan Africa, by Prabhu 'L Pingali, Yves Bigot and Hans PGBinswanger, May 1985.
eReort No.: ARU? 41Eastasian Financial Systems as a Challenge to Economics: The Advantages
of 'Rigidity', with particular reference to Taiwan, by Robert Wade,June 1985.