In this paper we discuss how the "encouragement design" used in randomized controlled trials can be extended to a setting with two treatments and one control group. Conditions to interpret the Two-Stage Least Squares (TSLS) estimates causally are stronger than in the case with only one treatment...

Contracting out public services to private firms has ambiguous effects when quality is imperfectly observable. Using a randomized experiment over a national sample in France, we compare the efficiency of the public employment service (PES) vs. private providers in delivering very similar...

Language is a strong and robust determinant of international trade patterns: Countries sharing a common language trade significantly more with each other than countries using different languages, holding other factors constant. In this paper, we show that this trade-promoting effect of language...

In this paper we explore the relationship between ethnic fractionalization and social capital. First, we test for time differences in the impact of ethnic fractionalization on social capital using U.S. data from 1990, 1997 and 2005. Subsequently we examine the data for evidence of the conflict,...

We investigate whether time-persistent cultural borders impede economic exchange across regions of the same country. To measure cultural differences we evaluate, for the first time in economics, linguistic micro-data about phonological and grammatical features of German dialects. These data are...