Javier Aparicio * javier.aparicio@cide.edu (Published in Voices of Mexico no. 77, UNAM, oct-dec. 2006) * Economist and professor at the Political Studies Division at CIDE, Mexico. This article summarizes work in progress, available at: http://www.cide.edu/investigadores/aparicio/elecciones/ Quick count, PREP and the district tally Fraud or human error in Mexico’s presidential election?