This thesis is composed of papers in applied microeconomics.
The first chapter studies how religious leaders influence their communities’ religious and political attitudes. To do this, I build a novel dataset containing the universe of Catholic priests appointed to their parishes in rural Spain between 2000 and 2019. I leverage the quasi-natural experiment by which foreign priests are allocated to parishes and use a staggered difference-in-differences design to identify their influence on their communities. I show that foreign-born priests, whom I find more devoted to their cause, are effective at revitalizing local religiosity, measured by an increase in Catholic marriages and fertility. They also influence local political opinions towards Catholic-aligned positions. However, such extra influence prevents parishioners from challenging the old status quo, measured by the higher maintenance of dictatorial honors, limiting social progress. These findings highlight that religious leaders have a considerable impact on sociopolitical attitudes. The second chapter, coauthored with Josep Amer-Mestre, studies the influence members of parliament with previous involvement in interest groups exert on their colleagues. To do so, we collect novel data containing the voting history, and résumés of all legislators present at the European Parliament between 2004 and 2019. Using the alphabetic allocation of seats, we find that seating beside reverse revolvers when the motion is relevant to their interest groups increases co-voting by 2.4%, attendance by 1.3%, and decreases abstention by 9%. These effects are driven by budget-related motions. Our results show that the revolving doors influence the political process even when working in reverse. The third chapter explores how reviewing time affects physicians’ medical decisions. I test this prediction using high-frequency data from a Spanish outpatient department and leverage on-the-day cancellations as exogenous time shocks. I find that longer visits lead to more valuable care, measured by the provision of more detailed diagnoses, to higher testing intensity, and to lower drug prescriptions. These effects are driven by junior physicians, who use this extra time to compensate for their more overloaded shifts.