Studies as the one posted recently https://www.telegraph.co.uk/family/parenting/university-students-arent-having-sex-parents-dont-know-whether/ suggest that there is a significant difference between the number of sexually active women and men in the typical age range 18-24. For example, this study shows that the number of sexually active males was 34% and for females it was 47%. While it's true that both sexes have seen a decline in sexual activity, the number for men went down much faster than for women. Often in this subreddit, when studies such as this one are mentioned marriage and financial issues are brought up by women (and some men) of this subreddit to explain the cause of this phenomenona. However this doesn't really apply to college age students. The other explanation often offered by women is that video games and pornography could be the cause, but anyone who has been to a UK university for example can attest that university students hardly play video games all day or stay in their homes 24/7. Most guys and girls are equally socially active and yet there seems to be this difference. Speaking from my personal experience, many guys try to get in relationships and have sex much harder than women in a university environment, so why do guys end up having less sex when they desire it way more?

EDIT: some replies here mention that women are dating older guys, but why do you think this discrepancy only been observed recently then? Didn't women always dated older guys?