Last night at the Democratic National Convention, many speakers made impassioned pleas for “common sense” gun reform. That might sound like a good idea but, like most public policy, gun policy is hard. 

As I wrote at the Washington Post website in December, using “common sense” to describe new gun policy is a “convenient piece of jargon that conveys level-headedness, non-partisanship, and empathy” without tackling the issues that drive gun crimes and gun deaths:

The United States contains an estimated 270 million to 310 million firearms. All gun crimes and gun deaths are overwhelmingly perpetrated with handguns, yet barely one quarter of Americans favor a handgun ban that would be required to lower that number significantly. So-called “assault weapons” and “high-capacity” magazines are easy political targets because they sound scary to people unfamiliar with firearms. However, restricting either or both would likely have no measurable effect on gun crime rates.

This week, the Washington Post published more information that should inform the push for more gun laws: less than 20 percent of all gun crimes are committed with legally owned firearms. This means that the overwhelming majority are committed with illegal weapons and/or by people who are not legally permitted to own guns. If lowering gun crime is the intended outcome of new legislation, most of the current proposals ignore 80 percent of the gun crime that happens in our country.

This is not to say there are no ways to improve our laws to reduce gun crime. But, with apologies to Burt Bacharach, what the policy world needs now are evidence-based solutions to our gun violence problem, not new laws that have no measurable effect on reducing gun crime.