The increasing amount of fake news has generated significant debate about the proper role of government and social media platforms in combating it. However, little is known about whether fake news can actually change behavior. This paper addresses this question by examining how vaccination rates responded to the unexpected surge in media coverage in 2007 of the verifiably false claim that the MMR vaccine caused autism. Specifically, I use a difference-in-difference approach to compare the MMR vaccination rates of children whose parents were most and least likely to be affected by the news over time. I determine parents’ susceptibility using three predetermined characteristics: whether their child is a firstborn, the child’s gender, and the parents’ age. Results show that susceptible parents were 3.3 percentage points less likely to vaccinate their children with an MMR shot by the recommended age of 15 months and 4.1 percentage points less likely to do so by 29 months. This indicates that at a minimum, fake news caused parents to delay vaccinating their children by over a year, and at most prevented them from ever immunizing their children.
A common educational practice around the world is to track students into classrooms based on ability. However, despite the popularity of tracking, relatively few papers directly identify the impact of being tracked into classrooms with higher or lower peer ability. This paper estimates the impact of being tracked into a classroom with higher ability peers by using data from public middle schools in Thailand, where students are tracked into classrooms based on a preliminary exam taken before 7th grade. Importantly, all teachers, curriculum, and textbooks are identical throughout classrooms. To distinguish the impact of peers from confounding factors due to selection, I apply a regression discontinuity design (RDD) that compares the academic outcomes of students just above and below the threshold. Results indicate that significant increases in peer quality do not improve student GPA. This suggests that any gains due to tracking, at least in Asian contexts similar to this, are likely due to factors other than peer quality, such as curriculum or teacher quality.
Coasian Bargaining in a Computer-Mediated Environment
(with Catherine Eckel, Ryan Rholes, and Jesse Backstrom)
Online, peer-to-peer transactions proliferated with the advent of markets like Craigslist and Facebook. Yet, we know little about how the characteristics of these markets shape consumer behavior. We test the Coase Bargaining Theorem (CBT) in a computerized environment to study if these online markets introduce behavioral wedges that change bargaining outcomes relative to face-to-face markets. We establish a baseline test of CBT in a face-to-face setting by replicating Hoffman and Spitzer (1982, 1985) and then implement their protocols in a computerized setting where we vary the property rights assignment mechanism and whether subjects engage in repeated bargaining. We replicate the original findings of Hoffman and Spitzer and then find that efficiency decreases significantly, and that self-regarding behavior increases significantly, in the computerized environment relative to face-to-face bargaining. These results suggest that Coase’s theorem may lack predictive power whenever negotiating environments introduce behavior inputs into the bargaining process.
An Empirical Test of Religious Discrimination (with Abigail Peralta)
Estimating the Impact of Juul on Teen Drug Use and Smoking