Dear Extra Credit: Christian N. Braunlich and you ["Questioning the Benefits of Preschool for the Middle Class," Oct. 23] missed the mark in your comments on the effects of a high-quality early-childhood education. First, a number of studies replicated the very positive results of the Perry......

Dear Extra Credit: Christian N. Braunlich and you ["Questioning the Benefits of Preschool for the Middle Class," Oct. 23] missed the mark in your comments on the effects of a high-quality early-childhood education. First, a number of studies replicated the very positive results of the Perry......