Rafael Prieto-Curiel is using quantitative tools to help measure and address organized crime in Mexico.Credit: Anja Böck In 2023, mathematician Rafael Prieto-Curiel published a paper1 that caused a stir in his home country of Mexico. He and his colleagues had developed a model to help understand the scale of the country’s drug cartels, which revealed that some 175,000 people worked in these organizations, making the cartels the fifth-largest national employer. As one of the few attempts to quantify the size of Mexico’s organized crime networks, the study received praise from diplomats and researchers alike — but it drew the ire of Andrés Manuel López Obrador, the Mexican president at the time. During a press conference in September that year, López Obrador argued that the findings were false. The president didn’t provide any evidence to support his argument.…