The rise of 'mass incarceration,' the term

Mass incarceration, the practice, has been going on for nigh on three decades in this country. But over the summer, Oliver Roeder at the Brennan Center curiously found that the phrase "mass incarceration" didn't come into popular use until more recently. Here's a summary chart (usage data from Lexis/Nexis):

Fascinating. When I searched Grits' archives, for whatever reason, I found that here, too, the first use of "mass incarceration" was in 2007. Before that, the blog pretty uniformly applied the term "over-incarceration" to the same concept. I couldn't begin to tell you where I picked up the term. By the time Michelle Alexander published The New Jim Crow: Mass Incarceration in the Age of Colorblindness in 2010, the term was in frequent use on this blog.

My guess: Perhaps the term's wider usage stemmed from 2007 congressional hearings titled  "Mass Incarceration in the United States: At What Cost?" Bruce Western used the term in a New York Review of Books article earlier that year. The earliest Grits use I can find was from February 2007 referencing the spread of immigration detention facilities. The first use of the term on the blog was actually by a commenter, Rev. Alan Bean of Friends of Justice, the month before.

¿Quien sabe? Funny how terms creep up on you. Without seeing the data, I wouldn't have guessed the usage was that recent.