Diagnosing the Productivity Effect of Public Capital in the Private Sector

Does public capital contribute to the productivity in the private sector? If so, which part of the private sector benefits most? Is public capital a substitute for or a complement of labor and private capital? This paper addresses these questions with both cost and profit function models estimated on U.S. time series data of the private sector and two of its subsectors. It pays special attention to nonstationarity in the data, to endogeneity in the price variables, and to the statistical and economic significance of the public capital effect.