With the decline of government-imposed trade barriers policymakers have given greater attention to the international distortions created by the practices of private firms, including cartels. We critically evaluate the techniques used in the economic literature to estimate the effects of these...

When a new firm enters a market and starts selling a spatially-differentiated product, the prices of existing products may rise due to a better match between consumers and products. Entry may have three unusual effects. First, the new price is above the monopoly price if the two firms collude...