Measuring Technical Change under Variable Returns to Scale: A Dual Approach.

In this paper, a dual measure of technical change is developed. The measure does not require parametric specification or estimation of the underlying technology, nor the assumptions of constant returns to scale and perfect competition. Imposing these assumptions, the proposed measure is shown to be equivalent to Solow's productivity residual. Biases attributable to these assumptions are analysed. Copyright 2000 by Blackwell Publishing Ltd and the Board of Trustees of the Bulletin of Economic Research