Fair Play at Voting Precincts: A Comparison of Mexican and Chilean Elections Patricio Navia Published in Democratisation, Volume 7.1 (Spring 2000) pp. 183-189 This papers looks at electoral data from voting precincts in Mexico 1994 and Chile 1993. I find that electoral results in Chile are more homogeneous across precincts than in Mexico. In Chile almost all the precincts returned results that resemble the aggregate national results. In Mexico, there are significant differences across precincts and across regions. I argue that perhaps the heterogeneity of the results across regions in Mexico helps explain the lack of credibility in the electoral process that persisted there in 1994 despite the reforms and measures adopted to make the process more fair. I also report significant regional differences in the level of support for all candidates in Mexico but not in Chile. I report on cases of apparent electoral tampering in Mexico, but I do not find evidence that possible electoral fraud significantly altered the electoral results. Finally, because support for different presidential candidates varied significantly across regions in Mexico, the inconsistencies between national aggregate results and precincts results aided by a history of electoral tampering might also help explain the credibility problem of elections in Mexico. Thanks to Jorge Buendía, Jorge G. Castañeda and James Vreeland for valuable comments. As usual, all errors and omissions remain my responsibility. The data used for the paper can be obtained from the author.