This thesis comprehends four essays investigating strategies to fight against poverty. The first essay explores a series of police operations to pacify the slums of Rio de Janeiro to understand the impacts of intrauterine exposure to violence on birth outcomes. One argues that pregnancies starting before, but ending around the pacification dates are ‘quasirandomly’ exposed to exogenous shocks of violence during pregnancy. The results show that each month pregnant women are exposed to pacification increases birth weights by 4 grams and reduces the probability of low birth weight (< 2500 grams) by 1.2 percent compared to pregnancies ending just before pacifications. A second essay uses Brazilian legislative change making it mandatory for private hospitals to publicly disclose information about physicians’ performance. The results show a reduction in scheduled C-sections by 4.8 percent; which two-thirds originating from physicians anticipating to information disclosure. The third essay proposes an empirical strategy to estimate bullying effects on labour and schooling outcomes when "true" bullying is observed inaccurately. The estimates show that high-school bullying decreases University attendance by 3.4 percent and increases the probability of being not in education, employed or in training after high-school by 2.8 percent. Estimations neglecting misreport implicates in impacts two-thirds smaller. And finally, the fourth essay shows that poor households increase their participation in social groups after receiving Bolsa Família. The strategy explores households registered in Cadastro Único, and performs a propensity score difference-in-difference framework to minimize selection bias. Becoming a recipient of Bolsa Família increases .09 standard deviations the number of social affiliation and increase from 6.1 to 8.9 percent the probability of engaging in social groups. Altogether, this thesis implicates that investing in early stages of life harvest significant benefits to disadvantaged children, it also shows that victims of bullying need sustained support after high school, and that conditional cash transfers foster social engagement.