The dramatic increase in the number of pre-kindergarten schools in Japan — also known as nursery schools — is applauded as a long overdue response to parental demand. But despite the fanfare, the movement is not a panacea. At least that's the hard lesson the United States learned much to its chagrin.

In a well-intentioned attempt to provide all children with the wherewithal to prepare them for success in later schooling, the U.S. launched Head Start, a ground-breaking program in 1965 as part of the War on Poverty. At the time, expectations were high that it would help level the uneven playing field for children from disadvantaged backgrounds and narrow the stubborn achievement gap.

But on Christmas Eve 2012, the Department of Health and Human Services released a 346-page report about Head Start. It concluded that the initial benefits faded by the end of the 3rd grade. In short, the $200 billion or so spent since the beginning did not produce lasting benefits. The decision to make the results public on that particular date alone, even though the report was dated October 2012, was seen by many as an attempt to bury the disappointing and embarrassing news.