Borders, Geography and Oligopoly: Evidence from the Wind Turbine Industry

Using a micro-level dataset of wind turbine installations in Denmark and Germany, we estimate a structural oligopoly model with cross-border trade and heterogeneous firms. Our approach separately identifies border-related from distance-related variable costs and bounds the fixed cost of exporting for each firm. In the data, firms' market shares drop precipitously at the border. We find that 40 to 50 percent of the gap can be attributed to national border costs. Counterfactual analysis indicates that eliminating national border frictions would increase total welfare in the wind turbine industry by 4 percent in Denmark and 6 percent in Germany.