I did a double take when I saw this, because I know for a fact that the federal prison population is in decline and has been declining for at least the last 24 months (I think it's actually 30 months, but I'm not sure).  I don't know anyone who even disputes this.  So I asked myself what is going on with Pew.

This is what is going on:  The study slams the door at the end of 2012.  The most plausible reason I can think of that Pew headlines with the present tense  --  claiming that prison time "surges"  --  is that its report was timed to coincide with the House Judiciary Committee's approval of the Sentencing Reform Act of 2015.  One of the most important reasons urged in support of that bill is that the prison population, and hence prison costs, are out of control.

It would undermine that rationale for Pew to issue a report titled, "Federal Prison Population Decline Continues," although that would more nearly capture the truth of the matter.

Bottom line:  The Pew report has about the same degree of trustworthiness as Linda Greenhouse's claim that the country has embraced a "widespread de facto moratorium" on executions, when, this year, we have had one every 13 days.