The effect of competition on the quality of health care remains a contested issue. Most empirical estimates rely on inference from non-experimental data. In contrast, this paper exploits a procompetitive policy reform to provide estimates of the impact of competition on hospital outcomes. The English government introduced a policy in 2006 to promote competition between hospitals. Using this pol...

We examine the impact of enforcing non-compete covenants (CNC) on the formation and performance of new firms using matched employer-employee data on 30 US states. To identify the impact of CNC, we exploit the inter-state variation in CNC enforcement along with the fact that courts do not enforce such covenants between law firms and departing lawyers in any state. Using a difference-in-differenc...

This paper provides a discussion of stamp duty and its effects. This is followed by an empirical study using changes in the rate of stamp duty in the UK as natural experiments. Because shares will be affected differently depending on how frequently they are traded, we can employ a difference-in-differences methodology. We find that the announcements of cuts in stamp duty had a significant and p...

Difference in differences (DID) require that the treatment rate is equal to 0% in the control group and during period 0 (no “always takers”) and to 100% in the treatment group in period 1 (no “never takers”). Sometimes, treatment rate increases more in the treatment than in the control group but there are never or always takers. This paper derives identification results applying to such setting...

In this paper we consider three questions. Why do only some firms enter export markets? What are the benefits to the firm from export market entry? Why do some of these firms exit the market at a future date? Using data on UK manufacturing firms from 1988 to 2002 we find evidence that information spillovers between firms can raise the probability of entry and for a matched sample of firms there...

United States fisheries are managed by regional councils. Fishermen can participate in fisheries managed by multiple councils, and effort controls in one region could lead to effort leakage into another. Using difference-in-differences, we test for leakage across regional fisheries boundaries for a catch share program in New England. We find evidence that the New England groundfish sector progr...

The generous Nordic model of welfare is commonly viewed as an exceptional success, in terms of both equality and economic growth. However, it recently became evident that subgroups of the population with weak labour market attachment and high welfare dependency, such as lone mothers, were vastly overrepresented among the poor. This prompted a workfare reform of the Norwegian welfare system for ...

This paper exploits the differential timing of the introduction of a labor market program across areas as well as agerelated eligibility rules to identify the treatment effect of a targeted active labor market program. We are especially concerned about substitution and equilibrium wage effects. The program studied is the “New Deal for the Young Unemployed” in the UK and uses an administrative p...