When a college football team is successful, students put down their books and pick up some beers.

At least, that is the case made by three University of Oregon economists whose study was released this week by the National Bureau of Economic Research.

In examining the grade-point averages of the Oregon student body and the performance of the Ducks’ football team, the researchers found a relationship between declining grades and success on the field.

“Our results support the concern that big-time sports are a threat to American higher education,” the paper’s authors — Jason M. Lindo, Isaac D. Swensen and Glen R. Waddell — wrote. They said their work was among the first to take a look at the “nonmonetary costs” of college sports.

Male students were more likely than female students to increase their alcohol consumption and celebrating and decrease studying when a team fared well, resulting in lower grade-point averages, according to the study.