The danger to young women on college campuses is well known now, but a new federal study shows an alarming new aspect: days of celebration lead to more rapes.

In a working paper (PDF) from the National Bureau of Economic Research, researchers report "significant and robust evidence that football game days increase reports of rape victimization among 17-24 year old women by 28 percent. Home games increase reports by 41 percent on the day of the game and away games increase reports by 15 percent."

The researchers said they believe the change is "driven largely by 17-24 year old offenders and by offenders unknown to the victim."

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This is remarkable because most rape victims report knowing their attacker.

The study focused on 128 colleges, and the authors estimated that anywhere from 253 to 770 additional rapes are reported each year at theses schools because of football games.

The authors took a look at "negative emotional cues" - in other words, upset wins and losses - and found a surprising correlation. While domestic violence incidents rise after upset losses in professional football, upset wins in college football increase the incidents of rape on campuses.

The researchers wrote they undertook the study because with a rapid rise in investment in big time college football programs, there's been relatively little done to examine the effect on the average student's everyday life and the university in general.

To that end, they produced a remarkable tally, writing: "Based on an estimated social cost of $267,000 per rape this implies an annual social cost of rapes caused by Division 1A games between $68M and $205M."