Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Does the social rate of return to physical investment exceed the private rate to an economically significant extent? In particular, is the return to investment in plant and machinery very high? We address this question by estimating a number of different models employing cross-section, time series and panel methods on data from the Penn World Table. The balance of the evidence suggests the answer to these two questions is no, particularly for the currently rich countries. The estimated elasticity of output with respect to capital seems roughly equal to capital's share and the estimated social rate of return is in line with estimates of the private rate. Copyright 1996 by Oxford University Press.