Do left-wing profs grade differently than right-wing profs?

Republican (right-wing) professors give a wider range of grades, including more extremely high and more painfully low marks, while registered Democrat (left-wing) professors grade students more equally, says a new paper to be published in the American Economic Journal. Researchers Talia Bar and Asaf Zussman theorized that Republicans, who are more likely to oppose redistribution of wealth, might also be more likely to oppose redistribution of grades from high-achieving to low-achieving students.

They appear to be right. In their study, average students — those who ranged from the twenty-fifth to the ninetieth percentile on the SAT (Scholastic Aptitude Test) — got the same grades from Republicans and Democrats, ranging from 3.0 to 4.0.

But students who were below the tenth percentile on the SAT received worse grades from Republicans than Democrats (2.0 versus 2.30) and high-achievers, those over the ninetieth percentile, were given higher grades by Republicans than by Democrats too (4.3 versus 4.0).

The study included the marks and SAT scores of 17,062 arts, humanities and physical sciences students who studied at an “elite” American university between 2000 and 2004. Political preference of professors was based on local voter registration records.

There is one caveat. Despite a large sample of 511 professors having participated, only 27 (5.3 per cent) were registered Republicans, while 370 (76.3) per cent were Democrats. Those widely divergent sample sizes somewhat increase the chance of a statistical error.