Logrolling for a Cause

Everyone knows that the main reason people participate in Greek life is because they have very fulfilling philanthropic commitments. Each semester, fraternities and sororities have an important philanthropy event focused on raising money for their respective causes. This semester, my fraternity planned an event for Thursday night focused on raising money to support mental health awareness. The sorority house located next to us planned an event for Wednesday night focused on raising money to increase childhood literacy. Before either of the events occurred, the sorority came to us and offered a deal: we'll go to your event if you'll come to ours.

My mind immediately went to the concept of log-rolling. Instead of exchanging votes, we'd be exchanging money to benefit our respective philanthropies. One of the problems with log-rolling is that the exchange can be non-simultaneous. Here, that problem was incredibly apparent. The sorority's event would occur on Wednesday, and ours would occur on Thursday. If we all showed up to their philanthropy event Wednesday night, they could simply renege on their promise and never show up to ours. How could this problem be solved?

The best solution I could think of (although not great for building trust) would be to have each fraternity brother come to the sorority's event and ask them for their upfront financial commitment to our event as well. Each member of the fraternity and sorority could pay for the cost of the other's event at roughly the same time (most likely over Venmo, of course), even though the sorority's event would take place first. The worst that could happen is that one fraternity brother pays for the sorority's event first, but then the sorority member does not Venmo the brother back. Of course, then none of the other fraternity brothers in line would make the exchange, and only one member of the fraternity loses his money. This is better than the other scenario in which all of the fraternity brothers make a financial commitment to the sorority's philanthropy, but none of the members of the sorority return the favor. Having this exchange one by one at the beginning of the sorority's philanthropy event would solve this problem of non-simultaneous exchange.

Luckily, we made the exchange without the above solution; both parties agreed to the terms and followed through on them, even though the sorority could have easily reneged on their promise. One possible reason the exchange worked is reputation. If the sorority reneged on their promise to come to our event, word might get around, and people would be unwilling to cooperate with the sorority on exchanging favors in the future.