Use of internal information, external information acquisition and customs underreporting

This paper identifies opportunities for improving the performance of revenue-collection authorities. To detect and combat fraud, we argue that revenue-collection authorities should, notably in the absence of reliable third-party information, exploit non-usual sources of information. Specifically, our micro-level study of customs evasion provides evidence that using any internal or external available source of information facilitates customsenforcement. Estimates highlight that exploiting historical data and/or relying on an information provider - a pre-shipment inspection company - significantly reduces evasion in Cameroon. The potential endogeneity of pre-shipment inspections is addressed by using instrumental variables. Results are robust to a variety of additional checks.