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 This example helps to explain the startling phenomenon currently taking

place with the so-called "Green Revolution" -- the rapid adoption of the new

high yielding varieties of wheat and rice [Rockefeller, 1968; Brown 1968].

 A second body of interesting evidence comes from the recent research of

Behrman [1966; 1969] on rice supply elasticities in Thailand. His study was

based on data from 50 Changwads (provinces) in Central and Northeastern

Thailand, 1940-1963. In estimating the short-run elasticity of area planted

to rice for the period 1940 to 1963, Behrman employed three independent measures

as surrogates for risk aversion: (a) the standard deviation in price over the

three preceding years; (b) the standard deviation in yields over three preceding

years, and (c) population residing in agricultural households. The choice of

the first two was based upon the strong presumption that they were suitable

proxies for the variances of the subjective probability distributions. For

both distributions, an asymptotically significant response was obtained in less

than half of the provinces. For both distributions, the mean value of the

implied elasticities with respect to the standard deviation is substantially

smaller than the mean value of the implied elasticities with respect to the

expected value of the same subjective probability distribution. The third

variable was seen as a reflection of possible peasant behavior in planting

enough area in rice to assure sufficient food for the household. For

approximately 70 per cent of the provinces the estimated response to this....

variable was symptotically significant. -/ The fact that the population/food

survival variable stood the test better than price or yield variability alone



1/ One final observation of Behrman's is that the pattern of rice supply
elasticities is highly correlated with the existence of profitable alternatives
[Behrman, 1966, pp. 366-691.