The recent movement to hold schools accountable for student performance has highlighted a simple fact: Many students are not achieving at desired levels.This simple fact has led people with widely varying reform perspectives to enter into the fray with plans and solutions. And a natural follow-on question is invariably “what will it cost?” To answer this important question, a series of very misleading methods for estimating the costs of an improved education have evolved, but the problems with these methods are generally unrecognized (or ignored) in the public and judicial debate.