It's not an urban legend: crime rates do in fact spike in the summer. A 2014 study from the Bureau of Justice Statistics found that, with the exception of robbery and auto theft, rates of all violent and property crimes are higher during the summer than during other months.
This recent study examined data from the annual National Crime Victimization Survey-a nationally representative sample of persons older than 12 year of age-collected between 1993 and 2010, which included violent and property crimes that did not result in death, both reported and not reported to the police. The data for nearly all types of crime show that, though the national crime rate plummeted by 70 percent between 1993 and 2010, seasonal spikes in summer remain. In some cases those spikes are 11 to 12 percent higher than rates during seasons in which the lows occur. But why?
Some researchers reason that increased temperatures-which drive many out of doors and to leave windows open in their homes-and increased daylight hours-which can lengthen the amount of time people spend away from their homes-raise the amount of people in public and the amount of time that homes are left empty. Others point to the effect of students on summer vacation, who are otherwise occupied with schooling during other seasons; still others postulate that suffering heat-induced discomfort simply makes people more aggressive and likely to act out.
Factors Influencing Crime Rates
From a sociological standpoint, though, the interesting and important question to ask about this proven phenomenon is not what climatological factors influence it, but what social and economic ones do. The question, then, should be not why are people committing more property and violent crime in the summer, but why are people committing these crimes at all?
Numerous studies have shown that rates of criminal behavior among teens and young adults drop when their communities provide them with other ways to spend their time and earn money. This was found to be true in Los Angeles during several time periods, where gang activity in poor communities was reduced when community centers for teens where thriving and active. Similarly, a 2013 study conducted by the University of Chicago Crime Lab found that participation in a summer jobs program slashed the arrest rate for violent crimes by more than half among teens and young adults who were at a high risk for committing crime. Generally speaking, the connection between economic inequality and crime is robustly documented for the U.S. and around the world.
The Impact of Structural Inequalities
Taking these facts into consideration, it seems clear that the problem is not that more people are out and about during the summer months, but that they are out and about in unequal societies that are not providing for their needs. Crime might spike at a time when a greater concentration of people being in public together simultaneously, and leaving their homes unattended, but that is not why crime exists.
Sociologist Robert Merton framed this problem with his structural strain theory, which observed that strain follows when the individual goals celebrated by a society are not made achievable by the means made available by that society. So if government officials want to address the summer spike in crime, what they should really focus on are the systemic social and economic problems that foster criminal behavior in the first place.