This dissertation comprises three independent chapters investigating the economic dimensions of language, education, and social interactions in multilingual and diverse contexts. Each chapter employs different empirical methodologies - respectively, structural methods, reduced-form tools, and experimental approaches - to analyze policy interventions and their impacts on human capital formation, educational outcomes, and social dynamics. The first chapter, "Language, Bullying, and Learning: School Choice in Multilingual Contexts," evaluates the effects of specialized educational programs for linguistic minorities, focusing on bilingual indigenous schools in Mexico, on academic performance in math and Spanish and on bullying. These schools aim to provide instruction in native languages and create safe spaces for minorities who often face discrimination; however, they encounter significant implementation challenges. I develop and estimate a structural model of parents choosing primary schools for their children that incorporates bullying as a key social interaction depending on the school ethnic composition and heterogeneous human capital formation technologies. I find that bullying consistently negatively impacts academic performance (by 0.15-0.38 standard deviations) and that increasing the proportion of indigenous students in a school from 0% to 100% reduces bullying for indigenous students by 7.3 percentage points, without affecting non-indigenous students. However, I find that teachers in indigenous schools are on average less effective than teachers in regular schools in promoting academic achievement. Their effectiveness is mediated by their indigenous language proficiency. Parental school choice is influenced both by academic aspirations and bullying concerns. I use the estimated model to evaluate counterfactual policies. Enhancing resources in indigenous schools improves academic scores and reduces bullying by encouraging student shifts from regular to indigenous schools. Policies targeting ethnic-based bullying improve academic performance directly and indirectly by fostering a conducive learning environment and encouraging students to choose more productive regular schools. Eliminating indigenous schools enhance academic achievement and reduce bullying for indigenous students attending regular schools, thanks to the influx of indigenous peers. Therefore, indigenous schools need additional resources to address minorities' education needs; otherwise, they risk being counterproductive. Chapter 2, "Global Language, Local Identity: English Education and Indigenous Skill Formation in Mexico," examines the effects of English instruction on indigenous children in public primary schools.As countries expand English instruction to promote global economic integration, policymakers often worry that this may weaken indigenous languages and cultural heritage. This paper examines this concern through a natural experiment in Mexico, where six states introduced English programs in public primary schools during the 1990s. Using a staggered difference-in-differences design and data from Mexico's School and Population Censuses, the study documents how English instruction unexpectedly strengthened indigenous language abilities. Exposure to English increased the likelihood of understanding an indigenous language by 3.5 percentage points and speaking it by 3 percentage points—substantial effects given the low baseline rates of 2.2% and 1.4%, respectively. The introduction of a global language appears to have encouraged students to reflect on and reaffirm their cultural identities: a 5 percentage point increase is found in Indigenous self-identification, accompanied by significantly greater geographic mobility. These results suggest that multilingual education can simultaneously promote economic integration and reinforce cultural distinctiveness. Chapter 3, "Diversity in Teams: Collaboration and Performance in Experiments with Different Tasks," examines the impact of demographic diversity on team performance. The effect of diversity is often considered to be a double-edged sword: more diverse teams benefit from increased creativity and knowledge sharing, but also face higher communication and coordination costs. This paper clearly distinguishes between two key aspects of team dynamics: performance and collaboration quality. The analysis tests this conventional view by utilizing an experimental setting within a large undergraduate class, where students are randomly assigned to small homework groups with varying levels of diversity in terms of race, gender, and place of birth. It is found that more diverse groups perform better on creative and complex tasks, but worse on standard tasks, confirming the consensus that the positive impact of diversity on team performance is contingent upon creativity gains. The effect of team diversity on teamwork quality is then explored by constructing an index based on collaboration between members, balance of contributions, and the absence of conflicts. This more behavioral dimension is found to exhibit a U-shaped effect of diversity, regardless of the task type. This result suggests that faultlines—dividing lines that split a group into subgroups based on demographic characteristics—can lead to a breakdown in inter-subgroup cohesion, while very homogeneous or highly heterogeneous groups tend to collaborate more effectively.