In this paper we examine the properties of a simple criterion-based, likelihood ratio type test of parameter restristions for standard GMM estimators in autoregressive panel data models. A comparison is made with recent test proposals based in the continuously-updated GMM criterion (Hansen,...

We consider to what extent the empirical failings of the Q model of investment can be attributed to the use of share prices to measure average q. We show that the usual empirical formulation may fail to identify the Q model when stock market valuations deviate from the present value of expected...

We derive robust predictions on the effects of uncertainty on short run investment dynamics in a broad class of models with (partial) irreversibility. When their environment becomes more uncertain firms become more cautious and less responsive to demand shocks. This result contrasts with the...

Cobb Douglas production function parameters are not identified from cross-section variation when inputs are perfectly flexible and chosen optimally, and input prices are common to all firms. We consider the role of adjustment costs for inputs in identifying these parameters in this context. The...

We report an empirical analysis of the responses of the supply and demand for secondary care to waiting list size and waiting times. Whereas previous empirical analyses have used data aggregated to area level, our analysis is novel in that it focuses on the supply responses of a single hospital...

In this paper we examine the panel data estimation of dynamic models for count data that include correlated fixed effects and predetermined variables.

This paper presents a life cycle model for the demand for health, and derives empirical specifications that distinguish between permanent and transitory wage responses. Using panel data, we estimate dynamic health and health input demand equations. We find evidence of negative transitory wage...

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...

The system GMM estimator in dynamic panel data models combines moment conditions for hte differenced equation with moment conditions for the model in levels. An initial optimal weight matrix under homoscedasticity and non-serial correlation is not known for this estimation procedure. It is...

Monte Carlo studies have shown that estimated asymptotic standard errors of the efficient two-step generalised method of moments (GMM) estimator can be severely downward biased in small samples. The weight matrix used in the calculation of the efficient two-step GMM estimator is based on initial...