Objective: To determine the cost utility of treating schizophrenic patients with olanzapine compared with other antipsychotics in a naturalistic outpatient setting. An Epoch analysis was used to analyze the longitudinal data. Multivariate regression analyses that adjusted for baseline...

The properties of two goodness-of-fit measures are analyzed for the instrumental variables model. One measure is based on the two-step approach to IV estimation and is equal to the coefficient of determination in the second stage equation. This measure therefore measures the fit of a...

Using many moment conditions can improve efficiency but makes the usual generalized method of moments (GMM) inferences inaccurate. Two-step GMM is biased. Generalized empirical likelihood (GEL) has smaller bias, but the usual standard errors are too small in instrumental variable settings. In...

Economics

We study the determinants of vertical integration. We first derive a number of predictions regarding the relationship between technology intensity and vertical integration from a simple incomplete contracts model. Then, we investigate these predictions using plant-level data for the UK...

How much does US-based R&D benefit other countries and through what mechanisms? We test the "technology sourcing" hypothesis that foreign research labs located on US soil tap into US R&D spillovers and improve home country productivity. Using panels of UK and US firms matched to patent data we...

This paper examines the relationship between foreign ownership and productivity, paying particular attention to two issues neglected in the existing literature – the role of multinationals in service sectors and the importance of R&D activity conducted by foreign multinationals. We review...

We examine whether discretionary government grants influence where domestic and multinational firms locate new plants, and how the presence of agglomeration externalities interacts with these policy instruments. We find that a region's existing industrial structure has an effect on the location...

We analyse a puzzle in the UK corporation tax: by both historic and international standards corporation tax revenues have been high while the statutory rate has been low. Possible explanations include the following: changes in tax law that may have increased effective tax rates; other factors...

We investigate the geographic concentration and agglomeration of production activity in the UK at the four-digit industry level using a variety of measures. We relate these to comparable patterns in the US and France and find several similarities. We find that conditioning on industrial...