The recent literature on instrumental variables (IV) features models in which agents sort into treatment status on the basis of gains from treatment as well as on baseline-pretreatment levels. Components of the gains known to the agents and acted on by them may not be known by the observing...

We use a natural experiment to show that the presence of an external examiner has both a direct and an indirect negative effect on the performance of monitored classes in standardized educational tests. The direct effect is the difference in the test performance between classes of the same...

We use a natural experiment to show that the presence of an external examiner in standardized school tests reduces the proportion of correct answers in monitored classes by 5.5 to 8.5% – depending on the grade and the test – with respect to classes in schools with no external monitor. We...

Unit roots in output, an exponential 2% rate of convergence and no change in the underlying dynamics of output seem to be three stylized facts that can not go together. This paper extends the Solow-Swan growth model allowing for cross-sectional heterogeneity. In this framework, aggregate shocks...

We use a natural experiment to show that the presence of an external examiner has both a direct and an indirect negative effect on the performance of monitored classes in standardized educational tests. The direct effect is the difference in the test performance between classes of the same...

We use a natural experiment to show that the presence of an external examiner has both a direct and an indirect negative effect on the performance of monitored classes in standardised educational tests. The direct effect is the difference in the test performance between classes of the same...

The effects of voluntary work on earnings have recently been studied for some developed countries such as Canada, France and Austria. This paper extends this line of research to Italy, using data from the European Union Statistics on Income and Living Conditions (EU-SILC) dataset. A double...

Instrumental Variables (IV) methods identify internally valid causal effects for individuals whose treatment status is manipulable by the instrument at hand. Inference for other populations inevitably requires some sort of homogeneity assumption. I develop a simple theoretical framework that...

This paper analyzes conditions under which various k-class estimators are asymptotically normal in a simultaneous equations framework with many weak instruments. In particular, our paper extends the many instruments asymptotic normality results obtained by Morimune (1983), Bekker (1994), Angrist...

This paper proposes shrinkage methods in instrumental variable estimations to solve the ``many instruments'' problem. Even though using a large number of instruments reduces the asymptotic variances of the estimators, it has been observed both in theoretical works and in practice that in finite...