Citation

Bhargava S, Pathania V. SSRN eLibrary 2008; 2008(online): ID 1129978.

Copyright

(Copyright © 2008, Social Science Electronic Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Previous research in the laboratory and by epidemiologists has compared the danger of cell phone use while driving to that of illicit levels of alcohol. This paper investigates the causal link between driver cell phone use and crash rates by exploiting a natural experiment - the discontinuity in marginal pricing at 9pm on weekdays when cellular plans transition from peak to off-peak pricing. We first document that this pricing threshold induces a 20 to 30% jump in call volume for two samples of callers. We then document the corresponding change in the fatal and all crash rate. Using the years prior to the introduction of two-tier pricing as a control, as well as weekends as a second control, we find no evidence for a relative rise in crashes after 9pm on weekdays from 2002-2005. The upper bounds of our estimates rule out increases in all crashes larger than 1.0% and increases in fatal crashes larger than 1.3% - these upper bounds reject the increases implied by most existing studies. An analysis of regional trends in cell phone ownership and crashes, legislation banning driver cell phone use, and differences in urban and rural ownership confirm our basic result. We discuss possible explanations and present a behavioral model to reconcile this counter-intuitive finding with existing research.