Do small cities need more public transport subsidies than big cities?

This paper compares the optimal public transport subsidies for a representative bus corridor in a small city (Karlstad) and in a big city (Stockholm) in Sweden. In the smaller city, the optimization of the fare is more important for welfare, whereas in the larger city, the frequency is more important. Moreover, the optimal subsidy is higher in small than in large cities because of larger positive externalities of reduced waiting and schedule delay costs, whereas the negative crowding externalities are larger in the large city. The bus subsidy is important for the income distribution in the small city.