Chapter 1: School Cellphone Bans and Student Substance Abuse: Evidence From California Public High Schools: Following high profile school shootings and the September 11th terrorist attacks, public concern over school emergency preparedness prompted the California State Legislature in 2003 to overturn a statewide ban against student possession of cellphones on campuses. After the repeal of the prohibition, which had been established in 1988 to curb drug dealing, school districts were allowed individually to either continue banning phones or modify their device policies; most opted over time to accommodate usage during certain hours of the day. Using fixed effects regression analysis clustered at the district level, I exploit variation in the timing of district policies to estimate the impact on substance abuse from lifting school cellphone bans. Results provide evidence that allowing students to use cellphones at school increases opportunities to obtain and abuse controlled substances; this effect is particularly pronounced in the incidence of marijuana smoking among 9th graders, who exhibit a 1.3 percentage point higher chance of reporting past-month marijuana use in the year a ban is lifted. Factors involved may include the capability that the technology provides to negotiate high risk interactions in private and to seek out and contact a relatively small number of drug suppliers; as is thus to be expected, no impact is found on the consumption of cigarettes, which can be obtained legally by a large proportion of high schoolers. Chapter 2: Impact of Internet Access on Student Learning in Peruvian Schools (with Leah Lakdawala and Eduardo Nakasone): We investigate the impacts of school-based internet access on pupil achievement in Peru, using a large panel of 5,903 public primary schools that gained internet connections during 2007-2014. We employ an event study approach and a trend break analysis that exploit variation in the timing of internet roll-out up to 5 years after installation. We find that internet access has a moderate, positive short-run impact on school-average standardized math scores, but importantly that this effect grows over time. We provide evidence that schools require time to adapt to internet access by hiring teachers with computer training and that this process is not immediate. These dynamics highlight the need for complementary investments to fully exploit new technological inputs and underscores the importance of using an extended evaluation window to allow the effects of school-based internet on learning to materialize. Chapter 3: Discretionary School Discipline Policies and Demographic Disparities: In 2014, California passed the law AB 420, becoming the first state to limit the use of school suspensions and expulsions as punishment for "willful defiance" - a subjectively determined offense thought by state lawmakers to lead to racial disparities in discipline. In this paper, I overview the state's recent (from 2012-2017) progress in reducing exclusionary discipline and note effects on disproportionality, here characterized as the difference between a given group's proportion of discipline and its proportion of enrollment. Using identification by treatment intensity, based on schools' pre AB 420 proportion of discipline attributable to willful defiance, I also attempt to gauge the effectiveness of reducing punishment of defiance in mitigating disproportionality. School level administrative data from elementary schools (spanning kindergarten through 5th grade) indicate that exclusionary discipline has considerably declined throughout the period. On the other hand, it does not appear that AB 420, along with lower willful defiance related discipline, has reduced disproportionality. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]