As the NPR introduction says: "In America, it is possible to work full time but not make a living. According to the Bureau of Labor Statistics, more than 20 million workers earn less than $9 an hour. At those wage levels, many people have trouble affording the basics -- housing, food, clothing, transportation and health care."
The NPR Special Report Low-Wage America by Noah Adams offers a series of profiles of people scraping by. This is how the other half lives - at least in America.