This dissertation studies different social factors that affect students' cognitive, non-cognitive skills, and behaviors. The first chapter provides evidence on the immediate effects of exposure to violent crimes on academic performance and externalizing behaviors among high school students. I find that exposure to violent crimes decreases PSAT, ACT/SAT scores, and exposure to homicides increases the likelihood of receiving a suspension, detention, or expulsion within 10 days following the exposure. The second chapter documents the spillover effect of teacher quality in terms of reducing absences. The results show that older siblings' teacher effects on absences have a moderate spillover effect on younger siblings, and a significant spillover of comparable magnitude also occurs from younger siblings' teacher effects on older siblings' absences. The similar findings between the two groups of siblings and the pattern of heterogeneity indicate that the spillover effects are mostly driven by parental behavior responses. The third chapter explores the effect of the Minimum Dropout Age law on student tobacco products and alcohol use. My results reject the hypothesis that there is an increase in the rates of tobacco products and alcohol use among students under 16 years old after the law is implemented. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]