Inverse Probability Weighted Generalised Empirical Likelihood Estimators: Firm Size and R&D Revisited

The inverse probability weighted Generalised Empirical Likelihood estimator is proposed for the estimation of the parameters of a vector of possibly non-linear unconditional moment functions in the presence of conditionally independent sample selection or attrition. The estimator is applied to the estimation of the firm size elasticity of product and process R&D expenditures using a panel of German manufacturing firms, which is affected by attrition and selection into R&D activities.