Selling plasma to survive: how over a million American families live on $2 per day

In early 2011, 1.5 million American households, including 3 million children, were living on less than $2 in cash per person per day. Half of those households didn't have access to in-kind benefits like food stamps, either. Worst of all, the numbers had increased dramatically since 1996.

Those are the astonishing findings Johns Hopkins' Kathryn Edin and the University of Michigan's Luke Shaefer discovered after analyzing Survey of Income and Program Participation (SIPP) data in 2012. In the intervening years, Edin and Shaefer sought out Americans living in this situation, with basically no cash income, relying on food stamps, private charity, and plasma sales for survival.

The result is $2.00 a Day, a harrowing book that describes in devastating detail what life is like for the poorest of America's poor. I spoke with Edin and Shaefer about the book Friday; a lightly edited transcript follows.