Candidate Name: Janine Rodrigues Rangel de Assis
Program: Public Polciy
Committee Chairs: Dr Glenn Dutcher
Committee Members: Dr Artie Zilante, Dr Lisa Schulkind, Dr Elizabeth Stearns
Abstract: This dissertation investigates the individual determinants of dengue prevention behavior in Brazil through three empirical studies unified by an Expected Utility framework that models preventive actions as decisions under uncertainty. Using original survey data collected in three Brazilian capitals during the 2026 dengue season, the chapters examine how individuals update risk beliefs, how these beliefs shape vaccine intentions, and whether social preferences contribute to community-level prevention. Chapter 2 evaluates whether exposure to epidemiological information alters perceived infection risk and stated preventive behavior. Respondents were randomly assigned national or state-level incidence statistics. Information increases perceived risk on average, but it does not have any meaningful effect on prevention behavior. Chapter 3 analyzes determinants of willingness to receive Brazil's newly introduced Butantan dengue vaccine. Perceived vaccine efficacy (post-vaccination infection risk), perceived severity of adverse effects, and perceived severity of dengue strongly predict uptake, while the probability of adverse effects is not significant. Chapter 4 examines whether other-regarding preferences, measured through a Dictator Game with strangers, neighbors, and friends, predict prevention behaviors with interpersonal spillovers. Giving increases with social proximity, but associations with preventive actions are heterogeneous: behaviors with clear external benefits correlate with prosociality, while others do not. Together, the findings show that dengue prevention in Brazil reflects a combination of belief updating, risk-based decision making, and social preferences, each operating differently across behaviors.