Working Papers

"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. The relationship between rule changes and drug use appears to be mediated by the times of day during which devices can be operated, further suggesting that changes in drug consumption are in fact linked to ease of campus cellphone communication. 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.

With Leah Lakdawala and Eduardo Nakasone

As developing countries increasingly look to Information and Communication Technologies (ICTs) to aid learning in resource-strapped classrooms, the Internet in particular may have an important role as a pedagogical tool. We investigate the impacts on pupil achievement of school-based internet access in Peruvian primary schools, studying the sample of all schools that gained internet connections during 2007-2014. We use an event study approach and a Comparative Interrupted Time Series specification to exploit variation in the timing of internet roll-out across schools. We analyze the dynamic effects of internet access on math and reading scores up to 6 years after installation. Controlling for school and year fixed effects, internet access appears to produce a positive impact on school-average standardized math scores, which grows over time. The effect is moderate in magnitude (about 0.02 standard deviations per year, peaking at 0.16 standard deviations by year 5) and statistically significant at conventional levels only after at least 1 year post installation. Consistent with the idea that new technologies need an adaptation period, this dynamic suggests the need for an extended time frame for the effects of school-based internet on learning to materialize. We show that these results are not driven by alternative explanations, such as score trends prior to internet access, changes in other school inputs, endogenous sorting of students across schools with internet, and changes in the composition of our panel. Observed gains in reading scores are smaller and insignificant in our main analysis. We explore two potential mechanisms with respect to our main result: the role of complementary investments to internet access (such as computer teachers and hardware) and increased individualized instruction.

Work in Progress

"Discretionary School Expulsion Policies and Demographic Disparities in Outcomes"

I investigate the impact of California law AB 420, which limits the use of school suspensions and expulsions as punishment for "willful defiance," a nebulously defined offense that many state lawmakers believe contributes to racial discrepancies in education outcomes. I aim to determine the effectiveness of the new legislation in mitigating disciplinary gaps using identification by treatment intensity, characterized as the pretreatment differences in the proportions of Black and White students suspended and expelled. Accounting for a preexisting downward trend in suspensions and expulsions over time, AB 420 appears to have lowered suspension rates among all categories of students, while also lowering expulsion rates of Black, White, and non-reporting students in particular. Using quintiles defined by treatment intensity, there is notably a positive and statistically significant effect of AB 420 on the proportion of Black students suspended in the bottom two quintiles (samples in which White students are suspended in slightly greater proportion than Black students). However, there is a larger and statistically significant negative effect on suspensions of Black students in the top quintile (the sample with the largest pretreatment disciplinary disparities). Altogether, preliminary results suggest that reducing administrator discretion in disciplinary action narrows gaps regardless of whether Black students are initially disciplined in greater proportion than White students or vice versa.

"Investigating Gender Differential Influence of the Home Environment on Children's Disruptive Behavior"

Bertrand and Pan (2013) observe that living in low quality home environments exacerbates the externalizing behavior of boys more so than that of girls. As the authors measure problem behavior using assessments by teachers and school administrators, I investigate the role of bias on the part of these officials in driving their results. I find evidence that gaps in suspension are strongly mediated by the gender of the school principal. I additionally analyze parent perspectives of child problem behavior; evidence suggests that boys’ behavior in broader social situations outside of school is also particularly sensitive to home environmental factors. Lastly, I observe that family structure determines the strength of the association between parent and teacher perceptions of boys’ behavior, but that this is not the case with girls.

"The Impact of Banning Cellphones on Student Achievement in NYC Public Schools"

From April 2006 until March 2015, New York City public schools enforced a ban on student cellphone possession by confiscating devices brought to campus. This project studies the effects of the decade long ban on academic achievement. Following Powell (2015) and Zou (2016), I use a synthetic control method for multiple treated units in order to construct counterfactuals of NYC public schools from the pool of other New York State public schools, based on standardized test performance from 2000 to 2005. From a difference-in-differences comparison of NYC schools to the sample of synthetic controls before and after the start of the ban, I estimate the ban to have produced a 4.8 percentage point improvement in the proportion of students achieving mathematics proficiency.