Reevaluating the effect of n-ach on economic growth

In this paper, we offer a review of McClelland's methodology in the definitive test of his original hypothesis regarding the effect of n-ach on modern economic growth. We find that though many of his methodological decisions seem to have been made post hoc, his findings for the period 1929-50 are largely substantiated. We then replicate the study for the period 1950-77, making improvements in variable proxies as suggested by McClelland in his original study. There is no support for McClelland's hypothesis in the 1950-77 period. In light of this finding and the absence of a close correlation between electricity production and purchasing power adjusted measures of GNP, we conclude that McClelland's original finding was the chance result of data mining.