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 compare the finite sample performance of a range of tests of linear restrictions for linear panel data models estimated using Generalised Method of Moments (GMM). These include standard asymptotic Wald tests based on one-step and two-step GMM estimators; two bootstrapped versions of these...

This paper reviews econometric methods for dynamic panel data models, and presents examples that illustrate the use of these procedures. The focus is on panels where a large number of individuals or firms are observed for a small number of time periods, typical of applications with microeconomic...

We present empirical evidence which suggests that a big increase in dividend taxation for UK pension funds in July 1997 affected the form in which some UK companies chose to make dividend payments, but otherwise had limited effects on both the level of dividend payments and the level of...

We consider a number of unit root tests for micro panels where the number of individuals is typically large, but the number of time periods is often very small. As we discuss, the presence of a unit root is closely related to the identification of parameters of interest in this context....

Aid providers frequently link supporting small firms to job creation. Small firms create about half of new jobs in Africa, but they also have higher failure rates. Ignoring firm exit exaggerates net employment growth. Using panel data for Ethiopia, we find that small and large enterprises create...

We use census panel data on Ethiopian manufacturing firms to analyze the connections between enterprise agglomeration, firm-level output prices and physical productivity. We find a negative and statistically significant relationship between the agglomeration of firms that produce a given product...

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...

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,...