One of the most fundamental questions for social scientists involves diffusion events; simply put, how do ideas spread and why do people embrace them? In Diffusion of Good Government: Social Sector Reforms in Brazil, Natasha Borges Sugiyama examines why innovations spread across political territories and what motivates politicians to adopt them. Drawing on a mixed-method approach that includes extensive field research and statistical analysis on the spread of model programs in education (especially Bolsa Escola, a school grant program) and health (Programa Saúde da Família, a family health program), she concludes that ideological convictions and professional norms were the main reasons why mayors adopted these programs, with electoral incentives playing a negligible role.