How to Measure Class Gap in Reading?

Carl Bialik:

The potential benefits to citing the questionable numbers are clear: Raise awareness and rally support. The downsides are more subtle. Boiling down research into misleading soundbites risks credibility of the larger argument advocating early reading, and it obscures other indicators that have equal or greater impact on a child’s intellectual development.
Todd Risley, professor emeritus of psychology at the University of Alaska and longtime children’s development researcher, argues that the amount and quality of parents’ talking to their young children is more significant.
“In even the ‘best’ of families, ‘shared reading time’ occupies very little of a child’s time,” he says. And income is a weak predictor of parental-child chatter, he adds, “so any statements about middle class and low income might be a little too glib.”