I have no proof of it, but I have to wonder how much children lose when their parents are not readers...not because they can't be taught to read, but because they get the message that reading is not an interesting thing to do. I know that I grew up with parents who read routinely and kept a lot of books in the home. That sends a message.
I work in welfare, and whenever I have to go to the lobby, I see a lot of clients waiting--they have to wait quite a long time to see someone. Not once have I seen someone reading a book. I can't imagine going to a place where I'd know I'd have to wait a long time and not bringing a book to read.