Association for Public Policy Analysis & Management

Causal evidence of the relationship between cell-phone use and traffic accidents remains scarce. Almost all of the literature so far has focused on police reports, self-report surveys, and analysis of drivers in simulators. Since using a telephone while driving is usually an illegal activity, it is possible that these studies present biased estimates. Despite this, laws restricting cell-phone use for drivers have been approved in numerous countries.

In this paper, I take advantage of a policy implemented in Chile between 2010 and 2012, which connected more than 1,000 rural areas to the mobile-phone network for the first time. This initiative, funded by the Chilean government, had the goal of reducing digital differences between urban and rural areas. At a cost of US$110 million, mobile-phone towers were constructed, and thus brought coverage to previously unconnected areas.

I geocode every accident that happened in the country between 2007 and 2014, and identify accidents that occurred in the specific areas covered by the new cell-phone towers. Geographically restricting the analysis to these zones, I estimate a differences-in-differences model to produce a causal estimate of the impact of cell-phone use on traffic accidents. Even if this should be interpreted as an intent-to-treat estimator, since it is not possible to know with certainty which accidents actually involved cell-phone usage, it provides a credible estimate of the effect of this activity on driving.

I find that cell-phone usage does increase the probability of an accident ocurring compared to other types of accidents caused by external factors, such as mechanical failures. Examining the heterogeneity of these results should shed light into the possibilty that cell-phone restricting policies could be improved if they targeted specific age-groups.