At age 8, Ed Klein sold drugs from the front door of his family's row home in Baltimore’s Pigtown neighborhood. For decades, the area has had some of the highest crime and poverty rates in the city.

"I hate to say it, but I wouldn't raise a dog in that part of town," he said.

They grew up in poverty, he said, his mother a single mom on welfare. "My mother never worked a day in her life," he explained. "The only job she ever had was sellin' dope."

When Klein was in first grade back in 1982, a group of researchers from Johns Hopkins University wanted to know what happened to children like him as they grew up.

So they began a landmark study tracking nearly 800 Baltimore schoolchildren, following them through school and into adulthood, until age 28. More than three decades later, they published the outcome in June, a book titled "The Long Shadow." It offers a searing and dismal view of the chances of escaping urban poverty.