“The two simple facts that explain why the US prison population exploded”

“A National Research Council report from 2014 debunked two big misconceptions about what caused the increase, and offered two big reasons: prosecution has become more efficient, and prison sentences have lengthened. Here's a guide:”

http://www.vox.com/2014/5/1/5669166/the-two-simple-facts-that-explain-why-the-us-prison-population

Ugh, prisons. What’s the point?