The evidence supports traditional approaches, even if Levitz pretends it doesn’t. Numerous studies have causally linked policing with significant crime declines, including a study of municipal expenditures on policing that found “reduced victim costs of $1.63 for each additional dollar spent on police in 2010, implying that U.S. cities are under-policed.” Levitz tells readers that such analyses don’t actually militate against his argument about how proper cost-benefit analyses shake out, because they fail to account for less visible social costs associated with law enforcement; but the same can be said about assessments of the toll that violence takes on communities—which goes far beyond the property damage and costs associated with injuries sustained by the victims. Indeed, studies have documented that violence affects everything from mental health to academic performance. Other studies have shown that merely increasing police presence produces crime declines in and around the affected areas. A study of increased police presence due to high-terror threat alerts in and around the National Mall in Washington, D.C. found that “an increase in police presence of about 50 percent leads to a statistically and economically significant decrease in the level of crime on the order of 15 percent.” An analysis of increased patrols around the University of Pennsylvania found that “extra police decreased crime in adjacent city blocks by 43–73%.” And an extensive review of the literature on proactive policing by the National Academy of Sciences concluded that “hot spots policing strategies,” “focused uses of stop, question, and frisk (combined with other self-initiated enforcement activities by officers),” and “broken windows interventions that use place-based, problem-solving practices” all produced statistically significant crime declines in the short term. As for incarceration, Levitz hangs his hat on the claim that “long prison sentences do not deter crime, and are actually counterproductive for public safety.” But the evidence on deterrence is more mixed than his piece lets on.