The empirical analysis of public infrastructure productivity has been limited by several econometric problems. These problems are probably the cause of the great variability in results reported in the literature. One of these econometric problems is the existence of multicollinearity when infrastructure is included as an input in a production function. In this paper, we propose to deal with multicollinearity by using priors on parameter values. For this purpose, we explore the use of maximum entropy econometrics to estimate the parameters of a regional production function in Spain. Our estimates show that infrastructure plays an important role in production.

Key words: Infrastructure, productivity, maximum entropy.
JEL classification: C13, C51, H54, R11, O47.