Spatial asymmetric duopoly with an application to Brussels’ airports

We study the problem of a city with access to two firms or subcentres (restaurants, airports) selling a differentiated product and/or offering a differentiated workplace. The first subcentre is easily congested (near city centre, access by road), the second less prone to congestion but further away. Both need to attract customers and employees and need to make profits to cover their fixed costs. This is an asymmetric duopoly game that can be solved for a Nash equilibrium in prices and wages. This solution involves excessive congestion for the nearby subcentre. Three stylised policies are studied to address this congestion. The first policy is to widen the congested road to the nearby subcentre. The second policy option is to add congestion pricing (or parking pricing etc.) for the congested subcentre. The third policy is to provide a direct subsidy to the remote subcentre so that it can reduce its price. We illustrate the theory using a numerical model applied to the two Brussels airports.