In studies that compare Internet use between groups, factor analysis is often used to create broader categories of use. Composite variables are constructed using a factor structure that fits the overall data. This approach overlooks tests that show whether the constructs are valid and whether...

When studying different types of returns to education, educational reforms are commonly used in the economics literature as a source of exogenous variation in education. The Swedish compulsory school reform is one example; the reform extended compulsory education throughout the country, in...

This paper investigates a unique feature of the English educational system to estimate the causal effect of compulsory schooling on labour market outcomes. We examine school leaving rules that allow for discrete variation in exit dates by date of birth within school cohorts. This natural...

This note provides a simple exposition of what IV can and cannot estimate in a model with a binary treatment variable and heterogeneous treatment effects. It shows how linear IV is a misspecification of functional form and the reason why linear IV estimates for this model will always depend on...

This paper studies robustness of bootstrap inference methods for instrumental variable (IV)regression models. We consider test statistics for parameter hypotheses based on the IV estimatorand generalized method of trimmed moments (GMTM) estimator introduced by Cížek (2008, 2009),and compare...

A new way of constructing efficient semiparametric instrumental variable estimators is proposed. The method involves the combination of a large number of possibly inefficient estimators rather than combining the instruments into an optimal instrument function. The consistency and asymptotic...

We establish the validity of higher order asymptotic expansions to the distribution of a version of the nonlinear semiparametric instrumental variable considered in Newey (1990) as well as to the distribution of a Wald statistic derived from it. We employ local polynomial smoothing with variable...

Recent work (including that of the author) on the impact of FDI has been based on microlevel (i.e. firms, establishments or plants) data, since this allows much greater control when examining such issues as whether FDI plants are more productive or innovative; whether there are spillovers to...