Hans Dietrich Ulrich Fricke

Against the backdrop of high macroeconomic instability and the need to meet the demands of public spending, we analyze the trade-off between growth and volatility of tax revenues in Latin America. Short-run and long-run elasticities for a sample of 11 economies are estimated accounting for state-dependent asymmetric reactions. Controlling for composition of revenue sources and other idiosyncrasies, we find revenues above (below) its long-run equilibrium to react stronger (weaker) to business cycle dynamics. Our detailed elasticity estimates can give some orientation on how to stably reach higher tax levels on the way to develop an adequate internal tax system.

This paper discusses identification based on difference-in-differences (DiD) approaches with multiple treatments. It shows that an appropriate adaptation of the common trend assumption underlying the DiD strategy for the comparison of two treatments restricts the possibility of effect heterogeneity for at least one of the treatments. The required assumption of effect homogeneity is likely to be violated because of non-random assignment to treatment based on both observables and unobservables. However, this paper shows that, under certain conditions, the DiD estimate comparing two treatments identifies a lower bound in absolute values on the average treatment effect on the treated compared to the unobserved non-treatment state, even if effect homogeneity is violated. This is possible if, in expectation, the effects of both treatments compared to no treatment have the same sign, and one treatment has a stronger effect than the other treatment on the respective recipients. Such assumptions are plausible if treatments are ordered or vary in intensity.

This study investigates how being exposed to a field of study influences students' major choices. We exploit a natural experiment at a Swiss university where all first-year students face largely the same curriculum before they choose a major. An important component of the first-year curriculum that varies between students involves a multi-term research paper in business, economics, or law. Due to oversubscription of business, the university assigns the field of the paper in a standardized way that is unrelated to student characteristics. We find that being assigned to write in economics raises the probability of majoring in economics by 2.7 percentage points, which amounts to 18 percent of the share of students who major in economics.