Access pricing and investment in vertical structures with complementary or rival facilities

In this paper we analyze the consequences of access pricing on infrastructure investment and intermodal competition. First, we analyze the optimal access prices to be charged to private operators. We find that the optimal access price to be charged for the use of a particular infrastructure depends on the existence of intermodal substitution or complementarity with other transport modes and infrastructures. Second, we analyze under which circumstances the investment in rail infrastructure is socially desirable both in a context with and without budget constraints. The positive net present value of the investment is not a sufficient condition. The necessary and sufficient condition implies a positive difference in social welfare for the cases in which the new infrastructure is and is not constructed.