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Hybrid Corn: An Exploration in the Economics of Technological Change

Zvi Griliches

Abstract

This is a study of factors responsible for the wide cross-sectional differences in the past and current rates of use of hybrid seed corn in the United States. Logistic growth functions are fitted to the data by states and crop reporting districts, reducing differences among areas to differences in estimates of the three parameters of the logistic: origins, slopes, and ceilings. The lag in the development of adaptable hybrids for particular areas and the lag in the entry of seed producers into these areas (differences in origins) are explained on the basis of varying profitability of entry, "profitability" being a function of market density, and innovation and marketing cost. Differences in the long-run equilibrium use of hybrid corn (ceilings) and in the rates of approach to that equilibrium (slopes) are explained, at least in part, by differences in the profitability of the shift from open pollinated to hybrid varieties in different parts of the country. The results are summarized and the conclusion is drawn that the process of innovation, the process of adapting and distributing a particular invention to different markets and the rate at which it is accepted by entrepreneurs are amenable to economic analysis.