The Abecedarian project that began in 1972 involved 111 infants in North Carolina, while the Perry project of 1962-on involved 123 poor children and their families in Ypsilanti, Michigan.

WSJ: Review & Outlook: Head Start for All

The empirical case for this expansion the evidence that universal preschool "works, " as Mr. Obama put it rests on two academic studies, the Abecedarian and Perry projects, conducted four and five decades ago.

WSJ: Review & Outlook: Head Start for All