The widely-held belief that talking on a mobile phone while driving increases the risks of car accidents has been contradicted by new research from LSE and Carnegie Mellon University.
In a study published this week in the American Economic Journal: Economic Policy, researchers from the two universities produced statistics which raise doubts about the veracity of claims connecting mobiles to car crashes.
Lead author Saurabh Bhargava, Assistant Professor of Social and Decision Sciences from Carnegie Mellon University, and his London School of Economics and Political Science colleague Vikram S. Pathania, say their findings reveal that increased mobile use by drivers has no corresponding effect on crash rates.
The pair used mobile phone and crash data from 2002-2005, a period when most mobile carriers offered pricing plans with free calls on weekdays after 9 pm.
Identifying drivers as those whose mobile calls were routed through multiple cellular towers, they first showed that drivers increased call volume by more than eight per cent at 9 pm. They then compared the relative crash rate before and after 9 pm using data on approximately eight million crashes across nine US States and all fatal crashes across the nation.
They found that the increased mobile phone use by drivers at 9 pm had no corresponding effect on crash rates.
Previous findings, including the influential 1997 paper in the New England Journal of Medicine, concluded that mobile phone use by drivers increased crash risk by a factor of 4.3 — effectively equating its danger to that of illicit levels of alcohol. , concluded that mobile phone use by drivers increased crash risk by a factor of 4.3 — effectively equating its danger to that of illicit levels of alcohol.
Bhargava and Pathania’s findings also raise doubts about the traditional cost-benefit analyses used by US States that have, or are, implementing mobile-driving bans as a way to promote safety.
"Using a mobile while driving may be distracting, but it does not lead to higher crash risk in the setting we examined," said Assistant Professor Bhargava.
"While our findings may strike many as counterintuitive, our results are precise enough to statistically call into question the effects typically found in the academic literature. Our study differs from most prior work in that it leverages a naturally occurring experiment in a real-world context."
Additionally, the researchers analysed the effects of legislation banning mobile use, enacted in several US States, and similarly found that the legislation had no effect on the crash rate.
"One thought is that drivers may compensate for the distraction of mobile use by selectively deciding when to make a call or consciously driving more carefully during a call," Bhargava said.
"This is one of a few explanations that could explain why laboratory studies have shown different results. The implications for policymakers considering bans depend on what is actually driving this lack of an effect. For example, if drivers do compensate for distraction, then penalising mobile use as a secondary rather than a primary offence could make sense. In the least, this study and others like it, suggest we should revisit the presumption that talking on a mobile phone while driving is as dangerous as widely perceived."
Pathania, a research fellow in the London School of Economics Managerial Economics and Strategy group, added a cautionary note. "Our study focused solely on talking on one's mobile. We did not, for example, analyse the effects of texting or internet browsing, which has become much more popular in recent years. It is certainly possible that these activities pose a real hazard."
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9 August 2013