The gang at the AEI-Brookings Joint Center have released a new working paper looking into the link between using a cell phone while driving and accidents. Employing new data and methods that go further than previous studies, the paper has three key findings: 1) Safer drivers tend to use hands-free devices already, so once you take that effect out of the statistics, it turns out that mandating hands-free devices won’t reduce accidents. 2) The effect of using a cell phone while driving depends on the person, and so previous estimates of the risk of using cell phones while driving, which don’t take into account this observation, may be overestimating the risk by 36%. 3) When more non-cell phone related differences in drivers are included, the effect of cell phone bans on accident risks become very small and uncertain. So much so that a ban on cell phone use while driving might well have no effect at all on accident rates. This should not surprise anyone, even the cops who see accidents which involve cell phone use. Bad driving is the problem, and bad drivers will more often use cell phones irresponsibly. Insurance and liability pressures are more likely to cure that problem than a cell phone ban, which punishes good drivers too.