Hybrid corn: An exploration in the economics of technological change
Citation: Zvi Griliches (1957) Hybrid corn: An exploration in the economics of technological change. Econometrica (RSS)
Internet Archive Scholar (search for fulltext): Hybrid corn: An exploration in the economics of technological change
Tagged: econometrics (RSS), corn (RSS), innovation (RSS), diffusion (RSS)
Griliches (1957) is a seminal econometric study in the diffusion of innovation. It begins by fitting a series of logistic (i.e., "S") curves to the diffusion functions based on proportion of people who had adopted hybrid seed corn. Broken down into different groups and functions by date, Griliches found that the the fit was extraordinary good (R-squareds of 0.98+) and could be expressed in terms of three variables: origins, slopes, and ceilings.
Griliches explains the different rate at which individuals enter into particular markets areas (differences in origins in terms of variation in profitability of entry, "profitability" being a function of market density, and innovation and marketing cost. Griliches explains differences in the ceilings in terms of differences in the long-run equilibrium use of hybrid corn and differences in slope as (at least in part) differences in the profitability of the shift from open pollinated to hybrid varieties in different parts of the country.
Theoretical and Practical Relevance
Hybrid Corn has been cited more than a thousand times and is a fundemental work in the literature on innovation more generally. It is particular important as perhaps the seminal work on the difussion of innovation. It was commented on in Econometrica by Robert Dixon in his article Hybrid corn revisited which was also responsed to by Griliches himself.
Although econometrically weaker -- it was done in the fifties after all -- it introduces a number of variables, theories, and models that have continued to be hugely influential in the economics literature more broadly.