A 1985 study published in Psychology of Women Quarterly presented subjects with a variety of fictional dating scenarios—mixing up who invited whom, who paid, and the venue—and asked them to evaluate the acceptability of the sexual encounter that followed. Disturbingly, they found that money contorted men’s opinions of sexual consent. “Rape was rated as more justifiable,” the authors wrote, “when the man paid all the dating expenses rather than splitting the costs with the woman.” Culturally speaking, 1985 may seem distant, but the study’s conclusion apparently hasn’t become any less relevant (or urgent): A more recent study, from 2010, found that men were more likely than women to think that sex should be expected when a man pays for an expensive date.

Through all these disconcerting findings, David Frederick still saw one data point that inspired optimism. Almost half of the men surveyed in the study he co-authored said that they would break up with a woman if she never offered to help pay the bill on a date. “In this single telling finding about dating and paying interactions, we see evidence of a sea change,” he and fellow authors wrote.