This is a long, but thoughtful and valuable read. Here is an interesting passage to whet your appetite:

… parents without a high-school diploma spent more than twice as much time each day with their children in the 2000s than they did in the mid-1970s, according to data from the American Heritage Time Use Study, marshaled by Harvard’s Robert Putnam. But parents with at least a bachelor’s degree increased their investment of time more than fourfold over the same period, opening up a gap in time spent with kids, especially in the preschool years.

The quality of time matters as much as the quantity of time, of course. In a famous study from the mid-1990s, Betty Hart and Todd R. Risley from the University of Kansas found large gaps in the amount of conversation by social and economic background. Children in families on welfare heard about 600 words per hour, working-class children heard 1,200 words, while children from professional families heard 2,100 words. By the age of three, Hart and Risley estimated, a poor child would have heard 30 million fewer words at home than one from a professional family.

I heard about this post from Matt O'Brien's Wonkblog article “Poor kids who do everything right don’t do better than rich kids who do everything wrong.”