Measurement Error in Access to Markets*

Microeconometric studies increasingly utilize travel times to markets as a determinant of economic behaviour. These studies typically use self‐reported measures from surveys, often characterized by measurement error. This paper is the first validation study of access to markets data. Unique data from Peru allow comparison of self‐reported variables with scientifically calculated variables. We investigate the determinants of the deviation between imputed and self‐reported data and show that it is non‐classical and dependent on observable socio‐economic variables. Our results suggest that studies using self‐reported measures of access may be estimating biased effects.