Econometric estimation of a variable rate of depreciation of the capital stock

Measuring the capital stock is crucial in some fields of economic research. Capital stock is not observable, though, and its estimation requires the knowledge of its rate of depreciation. In most cases, econometric regressions are not used for this task. However, this methodology could be used to estimate capital stock values which are consistent with the technology of the economy. If we assume that the depreciation rate is not constant, its estimation poses some additional technical difficulties. In this paper we suggest a method to estimate a variable rate of depreciation which is shown to have wide empirical applicability and some computational advantages. Also, this method is easily implementable in standard packages by means of NLS or ML. The formalization of this method, and empirical evidence and simulation exercises based on its implementation are presented.First version received: October 2002/Final version received: May 2004All correspondence to José A. Hernandez. We would like to thank to the University of Las Palmas project uni2002/14 for financial support and two anonymous referees for helpful comments.