Are Big Cities More Dangerous Than Small Ones?

<a href="http://www.shutterstock.com">PHB.cz (Richard Semik)</a>/Shutterstock

Fight disinformation: Sign up for the free Mother Jones Daily newsletter and follow the news that matters.


Are big cities more dangerous than small ones? Of course they are. This is so obvious that it’s not even a question most people would think of asking.

And yet, if you’ll bear with me for a bit, it turns out there’s more of a mystery here than you might think. In 1996, for example, Ed Glaeser and Bruce Sacerdote wrote a paper trying to figure out why there’s more crime in big cities. They came up with a couple of reasons. First, there’s more valuable stuff to steal in big cities, so robbery is more profitable. Second, it’s easier to be anonymous. If you mug someone in Mayberry, there’s a good chance your victim will recognize you and report the crime. Beyond that they threw up their hands, suggesting that perhaps the rest of the difference might be due to the fact that families are less intact in big cities. But even after running batteries of statistical tests, they were still left scratching their heads. Sure, there are more broken families in big cities, but that “still leaves unanswered the question of why this variable is so important in leading to criminal behavior.” What’s more, “the results on higher benefit levels and lower arrest rates are intriguing but also not entirely satisfying.”

Well, if that’s not satisfying—and it isn’t—how about an answer out of left field? Maybe the real answer is that big cities aren’t much more dangerous than small ones. Let me explain.

One of the hallmarks of a good theory is that it answers questions you didn’t even know you had, and it turns out that the answer to this mystery might lie in the association between gasoline lead and violent crime. I mentioned this briefly in “Criminal Element,” my magazine piece about the lead-crime connection, but it deserves a little more explanation. So here it is.

In a nutshell, the lead-crime hypothesis is simple: Exposure to gasoline lead in small children produces heightened aggressive tendencies. When an entire generation of children was exposed to lead in the ’40s, ’50s, and ’60s, thanks to the boom in auto sales after World War II, it led to a huge rise in violent crime when the children grew up in the ’60s, ’70s, and ’80s. The more lead they were exposed to, the more crime you got.

So where did we see the most exposure to gasoline lead? Answer: in places with the densest concentration of automobiles. And that’s in the inner core of big cities. In the early ’60s, big cities had double the ambient air lead levels of midsize cities, which in turn had air lead levels 40 percent higher than small cities. (Nevin, p. 316.) So if lead exposure produces a rise in crime, you’d expect to see a bigger rise in big cities than in small ones. Over time, big cities would become increasingly more dangerous than small ones.

Likewise, when lead was removed from gasoline, and children started to grow up normally, you’d expect to see a bigger crime decrease in big cities. Over time, crime rates would start to converge.

And that’s exactly what we see in the data. In the ’70s and ’80s, when big cities had their highest levels of lead-poisoned teenagers, they really were more dangerous places than small cities. But we began removing lead from gasoline in the early ’70s, and right on schedule, crime rates in big cities peaked in 1991 and then started falling. The chart on the right tells the story. The top line is average rate of violent crime for every city in America with a population greater than 1 million. (Only Chicago is missing, because it lacks complete data.) The bottom line is the average rate of violent crime for cities with a population between 100,000 and 250,000.

The convergence between big and small cities is startling, and the biggest cities have shown the biggest drops. Violent-crime rates have declined by more than 75 percent in New York City and Los Angeles since their peaks in the early ’90s.

So the surprising truth is that big cities are only a bit more dangerous than small ones. For a few decades it seemed otherwise, but this was mostly an artificial difference driven by higher concentrations of gasoline lead. Take that away, and it turns out that Los Angeles isn’t much different from Modesto.

AN IMPORTANT UPDATE

We’re falling behind our online fundraising goals and we can’t sustain coming up short on donations month after month. Perhaps you’ve heard? It is impossibly hard in the news business right now, with layoffs intensifying and fancy new startups and funding going kaput.

The crisis facing journalism and democracy isn’t going away anytime soon. And neither is Mother Jones, our readers, or our unique way of doing in-depth reporting that exists to bring about change.

Which is exactly why, despite the challenges we face, we just took a big gulp and joined forces with the Center for Investigative Reporting, a team of ace journalists who create the amazing podcast and public radio show Reveal.

If you can part with even just a few bucks, please help us pick up the pace of donations. We simply can’t afford to keep falling behind on our fundraising targets month after month.

Editor-in-Chief Clara Jeffery said it well to our team recently, and that team 100 percent includes readers like you who make it all possible: “This is a year to prove that we can pull off this merger, grow our audiences and impact, attract more funding and keep growing. More broadly, it’s a year when the very future of both journalism and democracy is on the line. We have to go for every important story, every reader/listener/viewer, and leave it all on the field. I’m very proud of all the hard work that’s gotten us to this moment, and confident that we can meet it.”

Let’s do this. If you can right now, please support Mother Jones and investigative journalism with an urgently needed donation today.

payment methods

AN IMPORTANT UPDATE

We’re falling behind our online fundraising goals and we can’t sustain coming up short on donations month after month. Perhaps you’ve heard? It is impossibly hard in the news business right now, with layoffs intensifying and fancy new startups and funding going kaput.

The crisis facing journalism and democracy isn’t going away anytime soon. And neither is Mother Jones, our readers, or our unique way of doing in-depth reporting that exists to bring about change.

Which is exactly why, despite the challenges we face, we just took a big gulp and joined forces with the Center for Investigative Reporting, a team of ace journalists who create the amazing podcast and public radio show Reveal.

If you can part with even just a few bucks, please help us pick up the pace of donations. We simply can’t afford to keep falling behind on our fundraising targets month after month.

Editor-in-Chief Clara Jeffery said it well to our team recently, and that team 100 percent includes readers like you who make it all possible: “This is a year to prove that we can pull off this merger, grow our audiences and impact, attract more funding and keep growing. More broadly, it’s a year when the very future of both journalism and democracy is on the line. We have to go for every important story, every reader/listener/viewer, and leave it all on the field. I’m very proud of all the hard work that’s gotten us to this moment, and confident that we can meet it.”

Let’s do this. If you can right now, please support Mother Jones and investigative journalism with an urgently needed donation today.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate