This dissertation consists of three essays on Labor and Development Economics. In Chapter 1, I investigate how the mandatory extension of collective bargaining agreements (ultractivity) increased labor unions bargaining power and affected firms hiring and firing decisions. Using matched employer-employee data and information on collective bargaining agreements (CBAs), I exploit variation in the timing of when a firm becomes subject to an ultractive CBA. I find that ultractivity reduces hiring, increases separations among high-tenure workers, and decreases separations among low-tenure workers. To interpret these results, I develop a framework in which firms anticipate higher adjustment costs under stronger labor protections and account for the substitutability between workers. Chapter 2 investigates the long-term effects of slavery on present-day Black homicide and incarceration rates. Using soil suitability for slavery-intensive crops as an instrument, I show that areas with greater historical slave intensity exhibit persistently higher levels of violence and incarceration affecting Black individuals. In Chapter 3, I apply the methodology proposed by Borusyak, Dix-Carneiro, and Kovak (2023) to estimate the effects of droughts and labor market changes on out-migration, focusing on Brazil s semi-arid region. I adjust local shocks by comparing them to the average conditions in typical destinations, weighting destination shocks by the share of past migrants from each origin to those areas. This approach shows that local aridity shocks alone no longer significantly affect emigration in recent years. However, relative economic conditions across regions remain a strong predictor of migration flows.