1 The Cobb-Douglas Regression and the Measurement of Economic Growth and its Causes

This paper is an excerpt from my projected book on the Cobb-Douglas regression. I use the phrase Cobb-Douglas regression to describe the empirical procedure of regressing a measure of output on measures of inputs, under the assumption that the production function takes what is now known as the Cobb-Douglas form. The procedure was introduced in Cobb and Douglas’s 1928 paper “A Theory of Production”, and Douglas continued to work with it for the next 20 years, producing a stream of studies in which the regression was applied to both cross section and time series data sets. Douglas’s work with the Cobb-Douglas regression attracted considerable comment, both positive and negative, from his fellow economists, but prior to the mid 1940s few outside of Douglas’s research group at Chicago actually used the regression. It was only over the two decades following the war that the Cobb-Douglas regression became something of a general purpose research tool for empirical economists, who adopted, adapted, and generalized the procedure to explore a variety of questions both micro and macroeconomic in nature. The material here comes from a segment of the book intended to describe how the Cobb-Douglas regression became a central tool in the effort by American economists to measure