Come Halloween, Yalies come out to play. Neatly stacked bales of hay and ubiquitous jack-o’-lanterns herald the start of a new season. Spirits are high.

But behind the gaiety, I also saw a gradual deterioration of our common living spaces. Pumpkins smashed by revelers were left rotting on Old Campus’ elegantly aged cobblestones for days. Someone decided to shred the neatly stacked bales of hay, littering the entire High Street entrance with straw. One night, I went into the common bathroom that I share with ten people on my floor only to see it scattered with glitter and sequins, presumably by Halloween partygoers dressing up.

But the fault is not just with the wrongdoer. It is with every one of us who walks past and thinks, “Someone else will deal with it.” When the party is over, how often do revelers think to clean up the mess they left behind?

But no harm done, right? We are the young and the free, and we paint this town red and leave our mark on the places we conquer.

Even beyond Halloween, some Yalies seem to treat the campus as their personal playground. I have seen birthday cake and sprinkles smashed on the ground in the Old Campus courtyard, trampled on by dozens of people who would rather step on it than clean it up.

I am sure that anyone living in a shared space would instantly recognize these situations. We all have that one parasite living with us who creates messes and spoils the space for everyone.

We may find an analogy for this situation in a classic economic problem — the tragedy of the commons. This problem arises when individuals disregard the common good in pursuit of self-interest. When many people share resources, some individuals try to reap the greatest benefit from the given resource. All it takes is a minority of people acting selfishly for the entire space to become damaged.

This is a collective action problem. Everyone living in common spaces would benefit from cleaning up messes when they happen or avoid making them altogether. But there is a perceived cost associated with doing so, so most people are not willing to act first.

The question then is: What is stopping people from acting to benefit the well-being of everyone? What is the perceived cost of doing something as simple as clearing litter when you see it?

Part of it is ego. Some people seem to think that, because we are Yalies, we shouldn’t have to do something as menial as cleaning birthday cake off the floor. It is easy to make grand claims about being responsible for the world we live in. It is not so easy to live in accordance with these virtues.

Part of the reason for this is probably a basic feature of capitalism: Workers exchange their labor for wages. Insofar as people do not get paid for what they do, no one is willing to act in a way that benefits society just for the sake of helping people. When I asked a friend if we should clean up the pumpkin mess, she looked surprised and said, “No, why should we?” When everyone has this attitude, you get gridlock.

Perhaps my friend thought that Yale custodians would deal with it. That makes me wonder if the way we conduct ourselves ought to be a mere function of financial transactions.

How can we claim to want to solve world problems such as climate change when we can’t even maintain our immediate environment? This mindset is what brings about collective action problems, such as climate inaction. When addressing certain problems is not directly beneficial to us, deferring responsibility to other people prevents us from acknowledging our unique ability to effect change. For instance, in to a speech from the Rose Garden in June 2017, Trump justified pulling out of the Paris Agreement by saying that Americans should not have to sacrifice for non-Americans.

We recognize that we have obligations that exist by virtue of our being part of this society. As part of a community, we ought to consider ourselves stewards of our own living spaces. Whether it is a dorm room bathroom or the Pacific Ocean, the principle is the same. It is only when more people start considering themselves responsible for their environment that we will ever be able to solve the tragedy of the commons.

No students ever cleaned up the glitter and sequin mess in our common bathroom. A Yale custodian probably took care of it. It is spotless now, but I know it won’t be for much longer. I’m hoping for a time when that will not be the case.

Ko Lyn Cheang is a first year in Grace Hopper College. Contact her at kolyn.cheang@yale.edu .