Pergamon

World Development, Vol. 24, No. 8, pp. 1373-1378,1996 Copyright 0 1996 Elsevier Science Ltd

Printed in Great Britain. All rights reserved 030.5-750x/96 $15.00 + 0.00

SO305750X(%)00036-8

Productivity of Public and Private Investment in

Developing Countries: A Broad International

Perspective

RAT1 RAM” Illinois State University, Normal, Illinois, U.S.A.

Summary. - Using reasonably good data for 1973-80, 1980-85 and 1985-90 for 53 developing coun- tries, fairly standard growth models are estimated to compare the productivity of public investment with that of private investment. The main point noted is that public investment appears more productive than private investment in at least as many instances as suggest the opposite. Much caution is, therefore, urged in making strong claims about the productivity of private investment in developing countries being higher than that of public investment. Copyright 0 1996 Elsevier Science Ltd

1. INTRODUCTION

The relative productivities of public and private investments in less-developed countries (LDCs) is obviously an important issue. Although the question is important and topical, very few studies have investi- gated the empirical evidence on the subject.’ One rea- son for the paucity of empirical research in this area might be the lack of good data on public and private components of investment for sizable multicountry samples. The careful work by Khan and Reinhart ( 1990), which is based on annual data for 1970-79 and covers a sample of 24 LDCs, is one of the few examples of the efforts to obtain empirical evidence on the sub- ject.* The present study extends the earlier research in three directions. First, a much broader crosscountry sample of 53 LDCs is used. Second, the position is assessed for the 1980s as well as the 1970s. For that purpose, three fairly homogeneous periods am consid- ered separately and also in pooled samples. Third, data on labor-force growth are used instead of the usual practice of taking population growth as a proxy for the growth of labor force. The main conclusion is that the parametric structure seems to differ substantially across the 1970s and the 1980s and public investment is seen to be more productive than private investment in at least as many cases as suggest the opposite.

2. MODEL, DATA, AND THE MAIN RESULTS

Following the common practice and the reasoning explained by Khan and Reinhart (1990, pp. 20-22), a

Solow-type “neoclassical” growth model is used, which may be written as

t, = a, + a,& + a, (PUBUY), + a,(PRVIIY), + u,g, + ui

(1)

where pi denotes the (annual) rate of growth of real GDP in country i during the period studied, i, stands for the rate of growth of labor force in that country and period, PUBIIY and PRVIIY stand for the shares (per- centage) of public and private investments in GDP, X, is the rate of growth of exports, and ui is the stochastic term. The specification, which is essentially the same as Khan and Reinhart’s (1990, p. 21) equation (5a), is quite standard except that most studies have used the sum (Z/Y) of public and private investment shares in GDP. The interpretation of the parameters is also straightforward. The coefficient a, is the elasticity of output with respect to labor; a, and ug are the marginal products of public and private investment respec- tively, and approximate the rates of return to these components; and a, is the output elasticity of exports, and the variable reflects the degree of “openness” of the country and constitutes a kind of “input” in the production function.3 As done by Khan and Reinhart (1990, p. 21) in equation (5b), estimates of equation (1) are also obtained after replacingXi by M, which is the annual rate of increase of imports. Although some

*Two anonymous referees of this journal gave useful com- ments on an earlier version of the paper. Haidong Ji provided helpful research assistance. The usual caveat, however, applies. Final revision accepted: February 27, 1996.

1373

1374 WORLD DEVELOPMENT

other variables can also be considered for inclusion and the model can be set up in several different ways, equation (1) seems to be a fairly standard specification and has the advantage of direct comparability with Khan and Reinhart (1990) and other similar studies.

The main source of data on the public and private components of aggregate investment is the compila- tion by Miller and Sumlinski (1994) who reported the numbers for 46 countries. This has been supplemented by the information for 10 West African countries, for which complete data are not available in the Miller- Sumlinksi compilation, that are included in the dataset kindly supplied by Mohsin Khan through a private communication. Information on the rates of growth of real GDP, labor force, exports, and imports is taken directly from World Bank (1991, 1993). Three fairly well-defined homogeneous periods are considered. One is the seven-year period 1973-80, which repre- sents the first post-oil-shock era; second is 1980-85, which can be regarded as the period after the (second) oil shock of 1979; and the third is the more recent era of 1985-90. World Bank (1991, 1993) constitutes a good direct source for the rates of growth for each of these periods. Since available data on public and pri- vate components of investment start with 1970 or 1971, it is not possible to work with any sizable period prior to the first oil shock of 1973. All data are entered in the form of annual averages for each period so that the effect of random factors does not dominate the esti- mates. The number of countries for which complete information is available for at least one period is 53. The actual sample size, however, varies with the period. Appendix A is a list of the sample countries.

Table 1 reports estimates of equation (1) for vari- ous periods witbX and M as alternative proxies for openness4 To judge the position for the entire decade of the 1980s and the entire sample period (in addition to that for each subperiod), estimates are also included for (a) averaged data for the lo-year period 1980-90, (b) pooled samples of 1980-85 and 1985-90, and (c) pooled samples for 1973-80.1980-85 and 1985-90.

It is easy to see that the regression fit is reasonable and the estimates generally show a plausible pattern. For instance, the labor parameter is not statistically significant in any of the models, which is a fairly typ- ical scenario in the estimates of such growth equations for the LDCs. In addition, as is commonly observed, the exports-growth and the imports-growth parame- ters show high statistical significance and are positive in all cases.5

Relative to the parameters of primary interest, if the estimates for 1973-80 are considered, a picture similar to that reported by Khan and Reinhart (1990, p. 22) is observed. The productivity of private invest- ment is large and positive and shows strong statistical significance, but that of public investment is much lower and statistically insignificant. This similarity with the Khan-Reinhart (1990) study is interesting

since the 41-country sample for 1973-80 in Table 1 is quite different from their 24-country dataset, and the periods are not quite the same.6

When the estimates for the 1980s are considered, the scenario undergoes a substantial change. To be sure about the sturdiness of the estimates, the position for the 1980s is studied fairly extensively by considering the data for the entire decade (198090) in addition to those for the subperiods 1980-85 and 1985-90 and the pooled observations for the two subperiods. It can be seen that in seven of the eight sets of estimates for the 198Os, the public investment parameters is positive, large and statistically significant, but the private invest- ment parameter is small and statistically insignificant at any sensible level.’ The pattern for 1980-85 is particu- larly dramatic and indicates an almost total reversal of the structure for the 1970s relative to the productivity of public and private investment.*

If the observations for the three periods are pooled to obtain an overall picture for the entire period that includes the 1970s and the 1980s the parameters for public and private investment reflect an “averaged” structure.9 The private investment parameters are now lower than those for the 197Os, but larger than those for the 1980s (with one exception). On the other hand, the public investment parameters are much higher than for the 197Os, but lower than most of the esti- mates for the 1980s. On the whole, the public invest- ment parameter is somewhat larger than the private investment coefficient, but both are statistically sig- nificant and roughly of the same order.

3. SOME METHODOLOGICAL EXPLORATIONS, AND SPECULATIVE

THOUGHTS ON THE OBSERVED PARAMETRIC STRUCTURE

Since cross-section models of the kind specified in equation (1) assume identical parameters for the sample countries, it is reasonable to have some uneasiness about the parametric stringency of such models. When pooled observations for several periods (“panel data”) are used, it is possible to improve the situation some- what by specifying a “fixed effects” model that permits the constant term to vary across the countries by includ- ing country-specific “intercept dummy variables.” The 141-observation sample based on pooled data for 1973-80, 1980-85 and 1985-90 was, therefore, reesti- mated after including 52 country-specific intercept dummy variables. The extended model, however, shows a lower explanatory power than equation (1) in terms of adjusted-R2, and the dummy variables are not jointly significant.1o This is an interesting methodologi- cal point, which suggests that the countries may be char- acterized by a fair degree of structural homogeneity, and, therefore, inclusion of country-specific intercept dummy variables represents an “overspecification.”

PRODUCTIVITY OF PUBLIC AND PRIVATE INVESTMENT 1375

Table 1. Comparingproducrivity ofpublic andprivare investment in LLXs: Estimates of equation (I) of the text (t-sratisrics are in parenhses)

Coefficient of

Period constant i PUBIIY PRVIIY t D R2 N

1973-80 0.714 (0.48) 1.125

(0.80)

0.042 (0.13) 0.178

(0.58)

0.071 (0.89) a.01 1

(-0.13)

0.253* (3.23) 0.213*

(2.74)

1980-85 -1.450 (-0.80)

0.100 (0.05)

0.028 (0.05) 0.035

(0.06)

0.299* (3.50) 0.211*

(2.44)

0.023 (0.26) 0.047

(0.59)

1985-90 -0.163 (-0.11)

1.149 (0.82)

-0.055 (-0.11) -0.271

(-0.58)

0.066 (0.81) 0.182*

(2.36)

0.167* (2.41)

,::;

1980-90 -0.448 (4.40)

0.943 (0.84)

0.005 (0.01) -0.129

(-0.37)

0.172* (2.81) 0.141*

(2.38)

0.068 (1.15) 0.064

(1.14)

Pooled 1980-85 & 1985-90

-0.034 (-0.03)

0.821 (0.79)

-0.199 (4.5 1) -0.138

(-0.40)

0.168* (2.86) 0.184*

(3.54)

0.086 (1.52) 0.054

(1.05)

Pooled -0.380 0.012 0.150* 0.136* 1973-80, (-0.41) (0.04) (3.00) (2.78) 1980-85 & 0.383 0.104 0.120* 0.105* 1985-90 (0.47) (0.42) (2.73) (2.45)

0.096t (1.69)

0.141* (2.49)

0.232* (4.05)

0.260* (4.77)

0.207* (5.51)

0.195* (5.86)

0.136* (2.53)

0.191* (3.62)

0.240* (4.98)

0.254* (5.43)

0.218* (7.94)

0.212* (9.29)

0.33 41

0.38 41

0.39 49

0.46 49

0.41 51

0.48 51

0.54 48

0.58 48

0.37

0.50

0.34

0.49

100

100

141

141

*Statistically significant at least at the 5% level. tStatistically significant at the 10% level.

Since this study basically uses Khan and Reinhart’s (1990) single-equation models, and the specification does not include several variables that have been considered by other researchers, it is useful to see whether there is any “bias” in the estimates due to some of the “omitted” variables being correlated with the included regressors, or due to there being a “feedback” from the dependent variable to some of the regressors.” One reasonable procedure for investigat- ing such a possibility is to conduct Ramsey’s specifi- cation-error test (RESET), which has been explained

by Ramsey and Schmidt (1976) and has been used by several researchers, including Goel and Ram (1994, p. 407). In its simplest form, the procedure consists of running a “test regression” in which the square of the predicted value of the dependent variable from the original regression is included as an additional regres- sor. If the estimated coefficient of the additional regressor in the test regression is not statistically sig- nificant, the hypothesis of “no specification error” is maintained. The test was conducted for each of the

first eight models included in Table 1. In no case was the t-statistic for the estimated coefficient of the square of the predicted-GDP-growth term in the test regression statistically significant at the conventional 5% level; at the 10% level, it was significant only in the 1985-90 equation with imports growth. Therefore, it seems unlikely that there is a major problem with the specifications used in the study.**

Although models specified in this study have been widely used, and Khan and Reinhart (1990, p. 20) have described such models as being the most popu- lar, some scholars have worked with growth of real GDP per capita as the dependent variable (which is equivalent to taking growth of aggregate real GDP as the dependent variable and having population-growth as a regressor), and have included initial GDP per capita also as a regressor by appealing to the “conver- gence hypothesis” or something similar. Appendix B reports a comparison of the estimates, for each of the four periods, with and without the logarithm of the ini- tial-year real GDP per capita (LRYO), which is taken

1376 WORLD DEVELOPMENT

from a recent update (PWT 5.5) of Summers and Heston (1991). It may be noted that the LRYO term is statistically significant at the 5% level in only two of the eight models, and the case for its inclusion is even empirically weak.13 Moreover, while the addition of the LRYO term lowers somewhat the estimated public investment parameters (and raises the private invest- ment coefficients), the broad pattern remains unchanged, and the contrast between the 1970s and 1980s is only slightly diminished.

The scenarios discussed so far are based on a direct and intuitive comparison of the point estimates of the parameters of public and private components of aggre- gate investment. It is also possible to conduct a formal test of the significance of the difference between the estimated parameters in each case. Although details are omitted here, the standard test for the equality of the coefficients of the public and the private invest- ment variables shows a significant difference at the 5% level in two cases in Table 1. In the model for 1973-80 with exports growth, the relevant F-statistic (1,35) is 4.77, showing that the private investment parameter is significantly larger than the public investment parame- ter; and in the model for 198G-85 with exports growth, the relevant F-statistic (1,44) is 4.92, indicating that the public-investment parameter is larger than the private investment parameter. I4 In al other cases one cannot reject the hypothesis of the equality of the public and the private investment parameters. Thus the formal tests, while reflecting the contrast between 1973-80 and 1980-85 fairly sharply, suggest that several seem- ingly sizable differences are not statistically significant at the conventional levels, and that in most cases one cannot reject the hypothesis that public and private investments are equally productive.

Last, some conjectures about the possible reasons for the difference in the scenarios for the 1970s and the 1980s may be in order. The difference is appar- ently not due to any major shifts in the relative magni- tudes of the public and private components of invest- ment. Considering 1973-80 and 1980-85, for which the contrast seems to be the sharpest, the (unweighted) sample means for the two components are quite simi- lar for the two periods: the means for public invest- ment rates are 9.5% and 9.6% in 1973-80 and 1980-85 respectively; the means for private invest- ment in the two subperiods are 11.9% and 11.3%.

Apart from the thought that the model specifications are fairly standard, the specification-error tests do not indicate any major problem, and the position has been compared for exactly the same models, it appears unlikely that the main reason may lie in the models used, An illustration of that view is provided in Appendix B, which indicates that the scenarios are fairly similar whether initial-year real GDP per capita is included or excluded. Moreover, although such esti- mates are usually sensitive to the sample coverage, my preliminary explorations indicate that neither the

income status nor the debt status of the sample coun- tries is likely to be a major cause of the observed differ- ences. For instance, in the low-income subsample the position is fairly similar to that in Table 1. For the “severely indebted” subsample also, the contrast is sim- ilar to that in the entire sample and is a little sharper.ls

The only speculation I can offer is that after the second oil shock of 1979, fiscal compulsions of the 1980s may have led to the channeling of the public investment into more productive uses than was the case before. On the other hand, productivity of private investment could have been hampered by inadequacy of complementary inputs, especially imported capital and intermediate goods. The data for the 1990s might shed some light on such a possibility.

4. CONCLUDING REMARKS

The paucity of empirical studies on the relative productivity of public and private investment in devel- oping countries seems as remarkable as the current prevalence of the belief that private investment is more productive than public investment. This study extends Khan and Reinhart’s (1990) work by estimat- ing their growth models to cover a considerably larger crosscountry sample and by including both the 1970s and the 1980s. While such estimates are subject to well-known caveats, Table 1 suggests a major contrast between the parametric structure for the 1970s and the 1980s. For the 197Os, as Khan and Reinhart (1990) note, private investment appears vastly more produc- tive than public investment. For the 198Os, however, there is a reversal of the pattern, and public investment seems more productive than private investment in most cases. Considering the overall (average) picture for the two decades, productivity of both components of investment seems fairly similar, but the public investment parameter is slightly larger. Although it is difficult within the limits of this paper to offer an ade- quate explanation for the contrast between the 1970s and the 198Os, it is possible that, due to the prevailing fiscal realities, public investment may have been directed toward more productive uses in the 198Os, and productivity of private investment may have been lowered by lack of complementary inputs. The main lesson suggested by the exercise is that, as additional data on public and private components of investment for the LDCs become available, the topic should be researched further, and that meanwhile much caution is needed in claiming or asserting that private invest- ment is more productive than public investment in developing countries. The methodological observa- tion that the addition of country-specific intercept dummy variables lowers the explanatory power of the model in terms of adjusted-R2 may offer some solace to those researchers who use cross-section data for samples of the kind that underlie this study.

PRODUCTIVITY OF PUBLIC AND PRIVATE INVESTMENT

NOTES

1311

1. Khan and Reinhart (1990, pp. 19-20, 25) have explained the importance of such studies. Therefore, only a brief mention is made here of the signiticance of the work. The explanation of the model is also very brief because they have provided a derivation for essentially the same model.

2. Besides other scholars, Greene and Villanueva (1991) have done useful work on the determinants of private invest- ment and some related aspects.

3. As Khan and Reinhart (1990) indicate, the constant term can be interpreted as reflecting exogenous productivity change.

4. It is easy to include additional sets of estimates by entering the total investment variable (I/Y), which is the sum of PUBIIY and PRVUY, in place of the two investment terms. It is also possible to enter Z/Y along with PUBIIY or PRVIIYor to have just one of PUBIIY and PRVUY. Such additional esti- mates, however, do not seem to contribute much. To focus on the main point, only the most basic results are included. Moreover, it is straightforward to conduct sources-of-growth exercises like those reported by Khan and Reinhart (1990). In view of the varying parameter structure for the two decades, however, the usefulness of such exercises appears limited rel- ative to the main purpose of this paper.

5. It is interesting to note that, although most scholars have used an exports-related variable as a proxy for trade ori- entation (or openness), all estimates in Table 1 indicate a bet- ter fit with imports growth than with exports growth. This may support the view suggested by Esfahani (1991) and other scholars that exports contribute to growth mainly by facilitating imports of highly productive capital and interme- diate goods. In the estimates reported by Khan and Reinhart (1990, p. 22). however, Rzs are higher in the specifications with exports growth than with imports growth.

6. Out of the sample of 41 countries in Table 1 for 1973-80, there are only 16 that were included in the Khan- Reinhart (1990) dataset.

7. The entire discussion in this paper is limited to the “direct” effects of public and private investment as reflected in the coefficients of PUBIIY and PRVIIY. In view of the pos- sible complementarity of private investment with certain kinds of public investment (e.g., infrastructure), noted by Khan and Reinbart (1990) and other scholars, the “final” (or “total”) return from public investment could be higher than what Table 1 suggests.

8. These patterns are very similar to those noted by Corlley (1995) in his study of the same issue for 14 West African countries.

9. Despite the large parametric variation across the three periods, it is of interest to pool the observations to see how the “overall” (average) position for the 1970s and the 1980s looks. Due to the observed structural heterogeneity across the subperiods, however, caution is appropriate in interpret- ing the pooled estimates.

10. Estimates for the extended model, that includes 52 intercept dummy variables, are not reported here. For the model that contains the exports-growth term, however, the adjusted-R2 without the country dummies is 0.32, and falls to 0.28 when the dummies are included. For the version that has the imports-growth term, adjusted-R*s without and with the dummies am 0.48 and 0.47 respectively. In both cases (witb exports-growth and imports-growth terms), the country dummies are not jointly significant even at the 10% level, and the F-statistics for their joint significance are 0.87 and 0.94. In addition, the inclusion of the dummies takes away the statistical significance of the investment parameter esti- mates. Complete details are available from the author.

11. It is, of course, obvious that even if there were such a “bias,” it is unlikely to lead to the parametric contrasts observed for identical models.

12. Complete details of these specification-error tests are available from the author.

13. These two cases are the estimates for 1980-85 and 1980-90 with exports growth. At the 10% level, the model for 1985-90 with exports growth also shows the LRYO term to bc significant.

14. At the 10% level, the difference is significant in three more cases, namely, for 1973-80 with imports-growth, 1985-90 with exports-growth, and pooled 1980-85 and 1985-90 with imports-growth. Additional details are avail- able on request.

15. The classification into the “low income” and the “severely indebted’ groups is based on the description given in World Bank (1993) for each country. Complete estimates are available from the author.

REFERENCES

Corlley, Chiavi, “Relative effects of public and private investment on growth in Economic Community of West African States (ECOWAS): 1973-1990,” M.S. thesis (Normal, IL: Illinois State University, 1995).

Esfahani, Hadi S., “Exports, imports, and economic growth in semi-industrialized countries,” Journal of Develop- ment Economics, Vol. 35 (1991), pp. 93-l 16.

Greene, Joshua and Delano Villanueva, Private invest- ment in developing countries: An empirical analysis,” Ih4F St& Papers, Vol. 38, No. 1 (March 1991) pp. 33-58.

Goel, Rajeev K. and Rati Ram, “Research and Development expenditures and economic growth: A cross-country

study,” Economic Development and Cultural Change, Vol. 42, No. 2 (January 1994), pp. 403411.

Khan, Mohsin S. and Carmen M. Reinhart, “private invest- ment and economic growth in developing countries,” World Development, Vol. 18, No. 1 (1990). pp. 19-27.

Miller, Robert R. and Mariusz A. Sumlinski, ‘Trends in private investment in developing countries 1994: Statistics for 1970-92,” International Finance Corporation (JFC) Dis- cussion Paper 20 (Washington, DC: World Bank, 1994).

Ramsey, James B. and Peter Schmidt, “Some further results on the use of OLS and BLUS residuals in specification error tests,” Journal of the American Statistical Association, Vol. 71 (1976). pp. 389-390.

1378 WORLD DEVELOPMENT

Summers, Robert and Alan Heston, “The Penn World Table World Bank, Trends in Developing Economies 1991 (Mark 5): An expanded set of international comparisons, (Washington, DC: World Bank, 1991). 1950-1988,” Quarterly Joumal of Economics, Vol. 106 World Bank, Trends in Developing Ecotwmie; 1993 (May 1991). pp. 327-368. (Washington, DC: World Bank, 1993).

APPENDIX A. LIST OF SAMPLE COUNTRIES*

Argentina, Bangladesh, Belize, Benin, Bolivia, Brazil, Burkina Faso, Cameroon, Cape Verde, Chile, Colombia, Costa Rica, Cote d’Ivoire, Dominican Republic, Ecuador, Egypt, El Salvador, Fiji, Gambia, Ghana, Guatemala, Guinea, Guinea-Bissau, India, Indonesia, Iran, Kenya, Korea (South), Madagascar, Malawi, Malaysia, Mali, Mauritania, Mauritius, Mexico, Morocco, Niger, Nigeria, Papua New Guinea, Pakistan, Paraguay, Peru, Philippines, Senegal, Sierra Leone, Sri Lanka, Tanzania, Thailand, Togo, Tunisia, Turkey, Uruguay, Venezuela.

*The 10 West African countries for which data on public and private investment are taken from the information supplied by M. S. Khan are Benin, Burkina Faso, Cape Verde, Gambia, Guinea-Bissau, Mauritania, Niger, Senegal, Sierra Leone and Togo. For all others, that information is based on Miller and Sumlinski (1994).

APPENDIX B

Table 1B. Comparison of the estimates with and without the initial-year real GDP per capita (LRYO): t-statistics are in parentheses below the estimates

Coefficient of

Period constant i PUBflY PRVIIY ri n;r LRYO R*

1973-80

1980-85

1985-90

198&90

4.297 0.040 0.037 0.279* (1.07) (0.12) (0.42) (3.37) 0.714 0.042 0.071 0.253*

(0.48) (0.13) (0.89) (3.23) 4.960 0.184 -0.052 0.239*

(1.29) (0.60) (-0.57) (2.94) 1.125 0.178 -0.011 0.213*

(0.80) (0.58) (-0.13) (2.74)

9641t (1.84) -1.450

(-0.80) 1.808

(0.40) 0.100

(0.05)

0.216 (0.39) 0.028

(0.05) 0.095

(0.17) 0.035

(0.06)

0.197* (2.11) 0.299*

(3.50) 0.200*

(2.19) 0.211*

(2.44)

0.075 (0.86) 0.023

(0.26) 0.060

(0.70) 0.047

(0.59)

6.6551‘ (1.75) -0.163

(-0.11) 5.780

(1.60) 1.149

(0.82)

0.076 (0.16)

4.055 (4.11) -0.199

(-0.43) a.271

(-0.58)

0.007 (0.09) 0.066

(0.81) 0.148t

(1.84) 0.182*

(2.36)

0.235* (3.10) 0.167*

(2.41) 0.092

(1.14) 0.046

(0.62)

8.798* (3.10) a.448

(-0.40) 3.928

(1.38) 0.943

(0.84)

0.074 (0.23) 0.005

(0.01) -0.105

(-0.30) -0.129

(4.37)

0.073 (1.18) 0.172*

(2.81) 0.109t

(1.68) 0.141*

(2.38)

0.120* (2.18) 0.068

(1.15) 0.092

(1.51) 0.064

(1.14)

0.103t (1.80) 0.096t

(1.69)

0.194* (3.27) 0.141*

(2.49)

0.258* (4.51) 0.232*

(4.05)

0.317* (6.20) 0.260*

(4.77)

-0.493 (-0.96)

0.143* -0.523 (2.65) (-1.07) 0.136*

(2.53)

-1.500* (-2.24)

0.187” a.255 (3.46) (-0.41) 0.191*

(3.62)

-1.019t (-1.94)

0.246* -0.680 (5.13) (-1.39) 0.240*

(4.98)

-1.258* (-3.49)

0.250* a.416 (5.37) (-1.14) 0.254*

(5.43)

0.34

0.33

0.40

0.38

0.45

0.39

0.46

0.46

0.45

0.41

0.50

0.48

0.64

0.54

0.59

0.58

*Statistically significant at least at the 5% level. tstatistically significant at the 10% level.