This paper aims to explore the determinants of profitability of Islamic banks in Sudan, one of the few countries that have total Islamic economic and banking systems. Using a sample of Sudanese banks, the paper found that only the internal factors to these banks have a significant impact on...

In this paper we survey methods to control for regression model error that is correlated within groups or clusters, but is uncorrelated across groups or clusters. Then failure to control for the clustering can lead to understatement of standard errors and overstatement of statistical...

Intellectual Property Rights (IPR) regimes for plant breeding are generally justified on the basis that they encourage innovation. Introduction of IPR regimes for plant varieties in the United States has led to increased concentration, but it is less clear whether IPRs have promoted useful...

We discuss fixed and random effects models in the context of educational research and set out the assumptions behind the two approaches. To illustrate the issues, we analyse the determinants of pupil achievement in primary school, using data from the Avon Longitudinal Study of Parents and...

The purpose of this paper is to examine Austrian foreign trade and estimate the country’s export function. The analysis is based on the gravity model of trade in the log-log form, augmented by additional variables in order to control for the impact of institutions on decision-making. Our panel...

Received stochastic frontier analyses with panel data have relied on traditional fixed and random effects models. We propose extensions that circumvent two shortcomings of these approaches. The conventional panel data estimators assume that technical or cost inefficiency is time invariant....

In this paper, we study the identification of a particular case of the 3PL model, namely when the discrimination parameters are all constant and equal to 1. We term this model, 1PL-G model. The identification analysis is performed under three different specifications. The first specification...

A meta-analysis of reported water demand elasticities shows that publication selection bias results in water demand estimates that overstate price elasticities. The analysis uses panel data estimators to measure and adjust for publication bias. A random effects estimator is used to derive water...