Private schools must be inflating their GPAs in order to position their students better in the job market, according to Stuart Rojstaczer and Christopher Healy. The New York Times reports  that the study “finds that G.P.A.’s have risen from a national average of 2.52 in the 1950s to about 3.11 by the middle of the last decade.”

For the first half of the 20th century, grading at private schools and public schools rose more or less in tandem. But starting in the 1950s,  grading at public and private schools began to diverge. Students at private schools started receiving significantly higher grades than those received by their equally-qualified peers — based on SAT scores and other measures — at public schools.