Labor and Capital Taxation with Public Inputs as Common Property

The services of many public inputs (e.g., dams, irrigation systems, and highways) are provided to private firms on a free-access basis. If these services enter constant-returns-to-scale production functions then there are decreasing returns to scale in the private factors. Thus a change in the amount of a public input gives rise to positive rent or economic profit in the first instance. The authors extend the literature by recognizing that this rent cannot be an equilibrium phenomenon. Private agents will engage in rent-seeking that will ultimately lead to dissipation. This makes a public input equivalent to a common property resource, which, in the absence of the appropriate price or quantity rationing, gives rise to inefficiency. Using a model with capital and labor as private inputs, the authors show it is optimal to tax capital even though a labor tax is available and capital is internationally mobile. Production efficiency also holds since our policy supports the first-best equilibrium despite decreasing returns to scale in private inputs.