Prison + Mental Institution Incarceration Rate:

Apropos Orin's post, and the news story it refers to, I thought I'd remind readers about Bernard Harcourt's guest-blogging last year on how looking at the fraction of people incarcerated in prison or mental institutions offers a useful perspective. Here's the key graph from Harcourt's work:

Unless, I'm mistaken, this graph includes prisons but not jails.