If we look at the evidence from some of the programs, there's a recent study of the U.S. head start program. You want to invest early. You want to target those investments to those who can ill-afford them, to answer the earlier question. But there's a “but”—you have to follow up. This is why you have to go through the entire educational continuum. If you don't follow up in the early education, the lead falls off.
