Getting Income Shares Right: A Panel Data Investigation for OECD Countries

In this paper we reassess the conventional measure of the capital share in income by estimating the shares of inputs in income for 23 OECD countries for the period 1960-2003 utilizing panel data techniques. A share of physical capital of over 0.50, and not one-third as commonly accepted, is found to be robust to a variety of specifications of the production function and the econometric models used. Additionally, we find that following the first oil shock the share of physical capital dropped while the share of human capital rose. Consequently, using the conventional shares may have led to overstating the severity of the post-1973 productivity slowdown.