These are the REAL Prison States

Strictness index: Which states are the toughest? The most lenient?

That 'strictness index' is a way of gauging how tough or lenient states are towards their criminals by looking at the net effects of how they apply criminal justice--namely how many people they put in prison--rather than by what statutes might say about how a particular crime is to be dealt with.

If a state has 500 people locked up and its crime index is 8,000, then its strictness index is 6.25 ((500*100)/8000). If another state locks up the same proportion of people, 500, but its crime index is only 6,000, it has a higher strictness index, at 8.33. The second state is thus tougher on its criminals than the more lenient first state is.

The crime index is figured by adding violent crime and property crime (both per capita) together, weighing violent crimes nearly 18 times as heavily as property crimes. Violent crime includes murder and non-negligent manslaughter, forcible rape, robbery, and aggravated assault. Property crime includes burglary, larceny, and motor vehicle theft.

A shortcoming is the absence of data on drug-related offences. Nearly one-quarter of inmates are in prison for such crimes. Unfortunately, I can't find numbers broken down at the state level for them.

Keep in mind, we're looking at the percentage of people behind bars relative to the percentage of people committing crimes. So a state can have lots of people in prison and still not be very strict, if it has lots and lots of crime.

The strictness index, by state:

State	Strictness
1. South Dakota	12.63
2. Mississippi	11.58
3. Idaho	10.74
4. Virginia	9.85
5. Kentucky	9.85
6. North Dakota	9.61
7. Wyoming	9.48
8. Wisconsin	9.35
9. Georgia	8.36
10. Louisiana	7.94
11. New Hampshire	7.67
12. Alabama	7.66
13. Connecticut	7.28
14. Vermont	7.16
15. Texas	7.06
16. Oklahoma	6.99
17. Indiana	6.88
18. Colorado	6.53
19. Montana	6.43
20. Maine	6.17
21. New Jersey	6.13
22. Pennsylvania	6.06
23. West Virginia	5.90
24. Utah	5.87
25. Arizona	5.76
26. Delaware	5.68
27. Ohio	5.61
28. Oregon	5.57
29. Kansas	5.43
30. Missouri	5.36
31. California	5.35
32. Iowa	5.12
33. Michigan	5.11
34. Nevada	5.00
35. Florida	5.00
36. Arkansas	4.98
37. North Carolina	4.98
38. Nebraska	4.92
39. New York	4.78
40. Hawaii	4.77
41. Alaska	4.72
42. New Mexico	4.68
43. South Carolina	4.62
44. Rhode Island	4.34
45. Washington	4.19
46. Tennessee	4.12
47. Maryland	3.94
48. Illinois	3.91
49. Minnesota	3.57
50. Massachusetts	3.38

Not surprisingly, conservative states tend to take a tougher stance on crime, liberal states a more lenient one (although the libertarian-left states of Maine, Vermont, and New Hampshire are relatively harsh). The correlation between strictness and Bush's share of the '04 vote is .47 (p-value of zero).

Geographically, the Northwestern interior and the South are the most stringent (with the notable exceptions of Arkansas, Tennessee, and the Carolinas), while the West coast and parts of the Midwest are the most permissive, but no clear patterns emerge (see a visual representation here--click on each of the ranges at the bottom left of the map to better distinguish individual states from one another).

And opposing mandatory sentencing in favor of judicial discretion, probation, and rehabilitation for serious criminals might not lead to degeneration in the streets of Cambridge, but in Tucson that outcome is more than just a theoretical possibility.

Or are the results even that contingent upon demographics of the state in question? The data suggests otherwise. The crime and strictness indices correlate positively at .52 (p-value of zero). States that are more willing to throw people into the slammer experience less crime even without adjusting for estimated IQ, affluence, average educational attainment, and the like.

How can that be if Mississippi is so strict and Massachusetts so lenient? Obviously you're at greater risk of being murdered in the former than you are in the latter. But Mississippi experiences relatively little crime for being a Southern state. The surprisingly lenient places in the South mentioned previously--Arkansas, Tennessee, and the Carolinas--all suffer from more crime than Mississippi does.

While Bay Staters can feel good about having a few less people in their prisons than North Dakotans can (356 to 359, respectively), they have to accept that the violent crime rate in Massachusetts is almost five times as high as it is in North Dakota! Nearby Connecticut incarcerates people at a rate more than 50% higher than Massachusetts does, yet it experiences less crime.

Similar relationships exist in other places. Take tranquil states like Wyoming and Nebraska, for example. The former incarcerates 690 people per 100,000 compared to the latter's 421. But despite (or perhaps in part because of) Nebraska's more diminutive prison population, its crime index is almost 20% higher than Wyoming's is.

Based on the proportions of their populations behind bars, you'd think Indiana suffered more from crime problems than does its more sophisticated neighbor, Illinois. Not so.

Even Minnesota, home to the fictitious Lake Woebegon (and in many ways its embodiment at the national level) experiences crime rates about 12% higher than the perpetually impoverished and 'backwards' state of West Virginia does. The coalminers throw more people in jail, though (443 to 300).