A Q model of investment is estimated using data for an unbalanced panel of UK companies over the period 1975-86. Correlated firm-specific effects and the endogeneity of Q are allowed for using a Generalised Method of Moments estimator. In the calculation of Q we estimate the tax incentives...

This chapter reviews developments to improve on the poor performance of the standard GMM estimator for highly autoregressive panel series. It considers the use of the system GMM estimator that relies on relatively mild restrictions on the initial condition process. This system GMM estimator...

We consider the estimation of Cobb-Douglas production functions using panel data covering a large sample of companies observed for a small number of time periods. Standard GMM estimators, which eliminate unobserved firm-specific e¤ects by taking first differences, have been found to produce...