Informal institutions in policing: unwritten rules in the National Police of Peru

This study examines how informal institutions—unwritten rules—shape policing in contexts of uneven state capacity. Drawing on qualitative fieldwork (32 interviews and three focus groups, 2022–2025) and spatial analysis of 1,332 police stations, it identifies five recurrent rules within the National Police of Peru (PNP). At the strategic level, the “police quota” embeds political patronage in senior appointments, reshaping promotion incentives. Operationally, officers rely on “living in precariousness” (the normalization of deficient and weakly auditable information practices), “let it be, let it pass” (calibrated inaction in high-crime settings), “friends of the police” (informal community support), and “comply and lie” (strategic decoupling in reporting). Together, these rules facilitate adaptation under conditions of scarce police resources and criminal pressure while heightening integrity and accountability risks. The findings have implications for police governance and reform in the Global South, especially promotion oversight, digital information practices, and territorially differentiated deployment and supervision.