Between 1984 and 1989 more than 20,000 tons of toxic chemicals, containing high concentrations of lead, were brought to the city of Arica (north of Chile). Initially, the chemical waste was located several kilometers from the city. The rapid expansion of Arica in the early 1990s, which included the construction of social housing projects meters away from the waste deposit, put at risk a large number of families. For more than a decade, individuals living in the vicinity of the contaminated areas were exposed to critical levels of lead. The medical literature suggests that even minimum lead exposure might have long-term consequences on individual's behavior and cognitive ability. However, there is little evidence on the direct effects on academic achievement and (fortunately) the literature rarely examines cases in which large number of individuals have been affected by lead exposure. In this paper we examine the effects of lead exposure on academic achievement studying the case of Arica. We analyze longitudinal data from a large population of individuals living and attending primary and secondary schools in Arica between 2004 and 2008. Our data include longitudinal information on proximity to the polluted areas (from individual's place of residence), levels of lead exposure, comprehensive sets of controls, and multiple nationally-representative academic test scores. Our findings indicate significant and negative effects of household's proximity to contaminated areas on student's academic performance. We also estimate the effect of blood lead levels on student academic performance finding significantly negative effects. Finally, combining these estimates with those obtained from regressions of annual earnings on student's academic performance we provide an estimate of the effect of lead exposure on life-time earnings.

We develop two different social network models with different economic foundations. In the local-aggregate model, it is the sum of friends' efforts in some activity that affects the utility of each individual while, in the local-average model, it is costly to deviate from the average effort of friends. Even though the two models are fundamentally different in terms of behavioral foundation, their implications in terms of Nash equilibrium are relatively close since only the adjacency (social interaction) matrix differs in equilibrium, one being the row-normalized version of the other. We test these alternative mechanisms of social interactions to study peer effects in education, sport and screen activities for adolescents in the United States using the AddHealth data. We extend Kelejian’s (2008) J test for spatial econometric models helping differentiate between these two behavioral models. We find that peer effects are not significant for screen activities (like e.g. video games). On the contrary, for sport activities, we find that students are mostly influenced by the aggregate activity of their friends (local- aggregate model) while, for education, we show that both the aggregate performance at school of friends and conformism matter, even though the magnitude of the effect is higher for the latter.

Does information about rampant political corruption increase electoral participation and the support for challenger parties? Democratic theory assumes that offering more information to voters will enhance electoral accountability. However, if there is consistent evidence suggesting that voters punish corrupt incumbents, it is unclear whether this translates into increased support for challengers and higher political participation. We provide experimental evidence that information about copious corruption not only decreases incumbent support in local elections in Mexico, but also decreases voter turnout, challengers' votes, and erodes voters' identification with the party of the corrupt incumbent. Our results suggest that while flows of information are necessary, they may be insufficient to improve political accountability, since voters may respond to information by withdrawing from the political process. We conclude with a discussion of the institutional contexts that could allow increased access to information to promote government accountability.