Researchers Jason Lindo, Peter Siminski, and Isaac Swensen have found that events that intensify partying on college campuses increase reports of rape by 28 percent. Offenders are typically in the same age range as the victims and include offenders known to the victim as well as those unknown.
Given that the majority of sexual assaults are not reported, the number of sexual assaults is likely much higher than reported. The researchers recommend limiting alcohol consumption at parties to reduce incidents of sexual assault.
Lindo, Jason M., Peter Siminski, and Isaac D. Swensen. December 2015. College Party Culture and Sexual Assault. NBER Working Paper No. w21828. Available at SSRN.