At the beginning of this century the Dutch government controlled the opium market in the Dutch East Indies--nowadays Indonesia--for several decades. This state monopoly was called the opiumregie. Using information gathered during the opiumregie, this paper estimates price elasticities of opium consumption. It appears that short-term price elasticities of opium use are about -0.7. Long-term price elasticities are about -1.0.

At the beginning of this century the Dutch government controlled the opium market in the Dutch East Indies--nowadays Indonesia--for several decades. This state monopoly was called the opiumregie. Using information gathered during the opiumregie, this paper estimates price elasticities of opium consumption. It appears that short-term price elasticities of opium use are about -0.7. Long-term price elasticities are about -1.0.

In this article we investigate the disincentive effects of shortening the potential duration of unemployment insurance (UI) benefits. We identify these disincentive effects by exploiting changes in Slovenia’s unemployment insurance system—a “natural experiment” that involved substantial reductions in the potential duration of benefits for four groups of workers plus no change in benefits for another group (which served as a natural control). We find that the change had a positive effect on the exit rate from unemployment—to new jobs and other options—for unemployment spells of various lengths and for several categories of unemployed workers.

A major issue in the analysis of unemployment durations concerns distinguishing genuine duration dependence of the exit rate out of unemployment from unobserved heterogeneity. We present a method for the nonparametric estimation of both phenomena, designed to be applicable to time-series data on aggregate outflows from different duration classes. The model explicitly takes into account that individual exit rates are affected by the business cycle and by seasonal effects. The method is applied to U.S. data. We find diverging duration effects among black and white individuals. However, except for white males, duration dependence is dominated by unobserved heterogeneity.

In the Netherlands, the average exit rate out of welfare is dramatically low. Most welfare recipients have to comply with guidelines on job search effort that are imposed by the welfare agency. If they do not, then a sanction in the form of a temporary benefit reduction can be imposed. This article investigates the effect of such sanctions on the transition rate from welfare to work using a unique set of rich register data on welfare recipients. We find that the imposition of sanctions substantially increases the individual transition rate from welfare to work.

Expert Opinion and Compensation: Evidence from a Musical Competition by Victor A. Ginsburgh and Jan C. van Ours. Published in volume 93, issue 1, pages 289-296 of American Economic Review, March 2003

The Declining Price Anomaly in Dutch Dutch Rose Auctions by Gerard J. van den Berg, Jan C. van Ours and Menno P. Pradhan. Published in volume 91, issue 4, pages 1055-1062 of American Economic Review, September 2001