# What effect has the US incarceration rate had on crime? **URL:** \ **Category:** Great Debates\ **Created:** [December 3, 2013, 5:17pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385 "2013-12-03T17:17:11Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![sweeteviljesus](https://avatars.discourse-cdn.com/v4/letter/s/898d66/32.png) [@sweeteviljesus](https://boards.straightdope.com/u/sweeteviljesus)\ **Post date:** [December 3, 2013, 5:17pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/1 "2013-12-03T17:17:11Z")
The crime rate in the U.S. has been falling ever since 1993. I believe things like mandatory minimum sentences started in the early '80s. How strong is the correlation between the two? Thanks, Rob ---
**Author:** ![sweeteviljesus](https://avatars.discourse-cdn.com/v4/letter/s/898d66/32.png) [@sweeteviljesus](https://boards.straightdope.com/u/sweeteviljesus)\ **Post date:** [December 3, 2013, 5:30pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/3 "2013-12-03T17:30:21Z")
[Here’s one source](http://www.economist.com/blogs/economist-explains/2013/07/economist-explains-16) ---
**Author:** ![Richard\_Parker](https://avatars.discourse-cdn.com/v4/letter/r/35a633/32.png) [@Richard\_Parker](https://boards.straightdope.com/u/Richard_Parker)\ **Post date:** [December 3, 2013, 5:34pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/4 "2013-12-03T17:34:54Z")
I realize your question is a limited one about numerical correlation, to which I do not have a ready answer. But on the issue of whether any correlation is more than random chance, the problem is that there are a lot of confounding variables on both the crime side and the incarceration rate side that line up along the same timeline, including but not limited to: rapidly declining lead levels; completely reworked mental health policies; altered policing policies; the changing nature of the drug war; economic change; and even abortion policies (if the Freakonomics folks are to be believed). ---
**Author:** ![sweeteviljesus](https://avatars.discourse-cdn.com/v4/letter/s/898d66/32.png) [@sweeteviljesus](https://boards.straightdope.com/u/sweeteviljesus)\ **Post date:** [December 3, 2013, 5:42pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/5 "2013-12-03T17:42:02Z")
According to that source I linked, the abortion thing has been discredited and the lead level thing is nearly so. I am aware that there are many factors or combinations of factors (hell, even abortion and unleaded gas may have contributed in some, though perhaps insignificant way), but if there is a correlation, doesn’t that mean the effects are related by definition (although correlation can mean both factors have the same cause rather than one causing the other)? I didn’t take statistics in school. Thanks, Rob ---
**Author:** ![Richard\_Parker](https://avatars.discourse-cdn.com/v4/letter/r/35a633/32.png) [@Richard\_Parker](https://boards.straightdope.com/u/Richard_Parker)\ **Post date:** [December 3, 2013, 5:47pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/6 "2013-12-03T17:47:10Z")
I don’t think the lead hypothesis has been discredited at all. The Economist wrote: > [@](#): > > Exposure to lead in childhood supposedly creates more impulsive and violent adults. That hypothesis is effective at explaining the reduction in violent crime in the United States but fits less well with other countries. . That’s not a very fair summary. It actually fits quite well internationally. Of course, the hypothesis is not disproven because France has a spike in its crime rate. (See: [Lead: America’s Real Criminal Element – Mother Jones](http://www.motherjones.com/environment/2013/01/lead-crime-link-gasoline)) As for correlation, no, it does not prove that the effects are causally related. There are so many different events in the world, that for any given event you can find hundreds of other correlations. Undoubtedly, there is some population of bird that has declined along with the crime rate–this doesn’t mean that the blue-footed tree owl controls our nations bank robbers. The Economist’s conclusion is probably correct: > [@](#): > > All or none may have contributed to the fall in crime, in different quantities in different countries. There’s not a lot of money to be made in criminological research. So the efforts to study these things just aren’t that comprehensive, to date. ---
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [December 3, 2013, 10:58pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/7 "2013-12-03T22:58:52Z")
Probably better in Great Debates rather than General Questios. You can still get factual answers there. Moved. **samclem** , moderator ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [December 3, 2013, 11:15pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/8 "2013-12-03T23:15:40Z")
Crime has been decreasing all over the developed world. Most likely it has to do with the reduced percent of males in the population who are in the prime “crime committing” years. Old farts don’t commit crime, and we’re becoming a nation of old farts. Let’s hear it for the old farts!! ---
**Author:** ![ITR\_champion](https://avatars.discourse-cdn.com/v4/letter/i/c67d28/32.png) [@ITR\_champion](https://boards.straightdope.com/u/ITR_champion)\ **Post date:** [December 4, 2013, 1:14am UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/9 "2013-12-04T01:14:58Z")
> [@sweeteviljesus](#): > > The crime rate in the U.S. has been falling ever since 1993. I believe things like mandatory minimum sentences started in the early '80s. How strong is the correlation between the two? The research I’ve seen has been in broad agreement that harsh prison sentences have had some small effect on driving down crime rates, but that the major drivers are more and better policing and more effective rehabilitation. > [@John Mace](#): > > Most likely it has to do with the reduced percent of males in the population who are in the prime “crime committing” years. Old farts don’t commit crime, and we’re becoming a nation of old farts. That’s true but doesn’t completely explain everything. The murder rate among teenagers is barely one third of what it was twenty years ago. ([Cite, with bonus debunking of abortion-crime relationship](http://www.isteve.com/abortion.htm).) ---
**Author:** ![Kobal2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kobal2/32/20_2.png) [@Kobal2](https://boards.straightdope.com/u/Kobal2)\ **Post date:** [December 4, 2013, 1:21am UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/10 "2013-12-04T01:21:39Z")
> [@ITR\_champion](#): > > That’s true but doesn’t completely explain everything. The murder rate among teenagers is barely one third of what it was twenty years ago. Well, what do you expect of millenials ? Lazy and unmotivated bunch. ---
**Author:** ![sweeteviljesus](https://avatars.discourse-cdn.com/v4/letter/s/898d66/32.png) [@sweeteviljesus](https://boards.straightdope.com/u/sweeteviljesus)\ **Post date:** [December 4, 2013, 4:26pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/11 "2013-12-04T16:26:57Z")
I hear they don’t bother learning to drive because they can do everything they want online. Maybe instead of drive-by shootings, they resort to cyberbullying until the target commits suicide. Rob ---
**Author:** ![Farin](https://avatars.discourse-cdn.com/v4/letter/f/e79b87/32.png) [@Farin](https://boards.straightdope.com/u/Farin)\ **Post date:** [December 4, 2013, 4:48pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/12 "2013-12-04T16:48:46Z")
> [@Kobal2](#): > > Well, what do you expect of millenials ? Lazy and unmotivated bunch. Gawd, do I have to go ALL THE WAY over to his house to shoot him in the face??THERE IS NO JUSTICE IN THIS WORLD. Btw, have you seen my DA profile? I’m up for collabs. 😃 ON topic: Incarcerations are a bad indicator of crime and a better indicator of past crime policy. How many people you have in jail shows how aggressive you were at punishing what was considered crime when they were put behind bars. For instance, right now there is probably someone in jail in Washington or Colorado for having an ounce of pot, which is now no longer a crime in those places. As incarceration rates rise, it’s an indication that the crime system is penalizing more and not an indication of overall crime. For instance, let’s say you get a speeding ticket. Well, now they don’t collect fines, they just throw you in jail for 30 days. Incarceration rates would skyrocket (assuming the same number of people were stopped for speeding). But it doesn’t mean that crime has gone up, necessarily. ---
**Author:** ![DrCube](https://avatars.discourse-cdn.com/v4/letter/d/a3d4f5/32.png) [@DrCube](https://boards.straightdope.com/u/DrCube)\ **Post date:** [December 4, 2013, 5:25pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/13 "2013-12-04T17:25:25Z")
Maybe there just isn’t as much poverty and desperation as there used to be? Does the trend in decreasing crime rate extend into the third world? ---
**Author:** ![sweeteviljesus](https://avatars.discourse-cdn.com/v4/letter/s/898d66/32.png) [@sweeteviljesus](https://boards.straightdope.com/u/sweeteviljesus)\ **Post date:** [December 6, 2013, 10:39pm UTC](https://boards.straightdope.com/t/what-effect-has-the-us-incarceration-rate-had-on-crime/675385/14 "2013-12-06T22:39:45Z")
[Well, isn’t that timely.](http://www.straightdope.com/columns/read/3138/does-no-more-lead-in-gasoline-less-violent-crime)