We develop a method to screen for local cartels. We first test whether there is statistical evidence of clustering of outlets that score high on some characteristic that is consistent with collusive behavior. If so, we determine in a second step the most suspicious regions where further...

This paper extends Hotelling's model of price competition with quadratic transportation costs from a line to graphs. We derive an algorithm to calculate firm-level demand for any given graph, conditional on prices and firm locations. These graph models of price competition may lead to spatial...

This discussion paper resulted in an article in the 'Journal of Industrial Economics' (2014). Volume 62, issue 3, pages 467-502.<P> Where markets are insufficiently competitive, governments can intervene by auctioninglicenses to operate or by forcing divestitures. The Dutch government has...</p>