Why your share house is messy, and what to do about it
Using Game Theory to model the challenges of living with housemates, and a solution to help them ‘clean up their act’
For many people in Australia, the share house has become a necessity to survive the on-going cost of living crisis. Whether it be with friends or strangers, Aussies are increasingly looking for extra heads in their households. Such a strategy enables share houses to reduce the financial burden of rents, utilities, or even food costs. Additionally, bunking up with your mates or even strangers provides the opportunity for new social connections — who knows what lifelong friends you may meet in the lucky dip of roommates.com?
Of course, anyone who has actually lived in shared accommodation knows it’s not always sunshine and rainbows. Even if you know the people you’re moving in with, you never really know what living with another person is going to be like until it’s week three and you’re complaining to a third party about the way your housemate clinks the sides of their cup when stirring their coffee. All the little idiosyncrasies, quirks, and habits (good and bad) come to the surface when sharing some of the most intimate spaces with another.
Public Goods and problems with free riders
One of the most difficult aspects with shared accommodation is ensuring the space remains clean. The reason why this can be so difficult is because a clean space is what is known as a public good to tenants. A public good is a relationship you and others have to a particular good which is both non-excludable and non-rivalrous. Non-excludable means that it is very difficult or impractical to deny someone from using or experiencing a particular good while also ensuring that others can experience and use this good themselves. Non-rivalrous means that one person’s experience of the particular good has little to no impact on another person simultaneously experiencing this good.
In the case of a share house, the good that we are relating to is the house itself. The relationship to it is the state of cleanliness. Non-excludability, in this context, means that if the share house is in a particular state of cleanliness, it is impossible for one member of the house to experience this state of cleanliness while another member simultaneously experiences a different state of cleanliness. If you and your housemate both stand in a clean kitchen, they cannot exclude you from this cleanliness (say by making it dirty) without also making the space dirty for themselves. Likewise, a clean kitchen would be non-rivalrous, since your own satisfaction with the cleanliness of the space does not detract from your housemate’s satisfaction with the clean space.
“Once a space has been used, a house member must act to return the space to its original condition”
But if someone were to use the kitchen, by say cooking a meal and leaving it dirty, then did that one person’s enjoyment of the clean state affect another’s enjoyment? Would that make it rivalrous? In short, no. In this case, when cooking a meal one is not using the kitchen for its cleanliness. To use a kitchen for its cleanliness would involve sitting and basking in the clean state. When basking, two people both sitting and enjoying a clean space would not have an impact on each other’s enjoyment of this clean space. Thus this use is non-rival. Something has occurred though when someone does use the kitchen for its instrumental purpose, such as cooking. When cooking in the kitchen, what occurs is not a change in the relationship with the good, but rather the good itself. After a kitchen has been used and is left dirty, we still experience the state of the kitchen as non-excludable and non rivalrous. However, now the state itself is not clean but rather dirty. We could say then that our public good has been replaced with a public bad.
Thus, there is a complex relationship between housemates and the state of the house, because to use the house in instrumental ways will almost necessitate an undesirable reconstruction of the public good in some way or another. This does not mean that to ensure the public good of a clean house is maintained, nothing should ever be used. No, it just means that once a space has been used, a house member must act to return the space to its original condition; that is, to clean up after themselves.
Herein lies the challenge of maintaining a clean house. Because the cleanly state of a house is a public good, so long as one person regularly cleans, all members of the house can enjoy a clean space. Those who do not contribute to cleaning the house yet enjoy this public good are known as free riders. And boy, do we all know a household free rider. The person that never washes their dishes, rarely cleans the shower, or wouldn’t be caught dead taking out the bins. Yep, that’s them. And you know what, as one of those people that does a lot of cleaning, we’ve all fallen into the trap of thinking, “well, if I do one more big clean, then all they have to do is maintain by cleaning up after themselves”. Unfortunately , this doesn’t work, and a bit of game theory can help us understand why.
Using Game Theory to understand our housemate’s habits
“Every time we clean, we provide further incentive for our housemate to not clean.”
Game theory hopes to articulate and help us understand how the preferences of individuals can motivate their actions, and how these actions produce particular outcomes. We can model these relationships in a game theory matrix, which places the actions of particular agents against the actions of others to illustrate the different outcomes available in a given situation. Mapping this to our situation of keeping a clean house can help us understand why individuals act the way they do.
To do so, we first take the preferences of our non-cleaning housemate. It needn’t be a difficult task requiring much analysis. Let’s say that our less-than-clean friend values having a clean house, but also values doing as little cleaning as possible. In this situation, the actions that are available to them are quite simple: to clean or to not clean. In choosing a particular action, our housemate will receive some utility. For simplicity, we will suggest that living in a clean house is worth 10 utiles to our housemate, and a dirty house will be the inverse (negative 10 utiles). The act of cleaning will result in the negation of 5 utiles due to the opportunity cost of participating in whatever else they wish they were doing. To not clean allows them to do whatever else they would rather do than to clean and is thus worth an additional 5 utiles .
For additional simplicity, we will model our dirty housemate’s behaviour as if their actions were universalised. That is, if everyone else in the house had the exact same preferences and payoffs as them. Furthermore, we will also presume that the house is already clean and that only cleaning up after oneself is required to maintain the public good of a clean house. So, with all this information, let’s create a matrix to help understand why our friend never cleans.
Here we see that our housemate has a dominant strategy to not clean up after themselves. This is because in a world where all other housemates elect to clean up, our dirty housemate receives greater utility from not cleaning than they would from cleaning (15>5). Likewise, even when no one cleans, it is still preferable to not clean than to clean (-5>-15). Thus, no matter what anyone else does, our dirty housemate’s preference is always not to clean.
This helps us understand why cleaning the entire house one last time fails to invigorate our housemate to clean up after themselves. When we do this one big clean we ensure that our housemate receives the highest possible utility from the options available. If anything, we provide reward for their free riding. Thus, every time we clean, we provide further incentive for our housemate to not clean. So, does that mean we should stop cleaning? No. Remember, they have a dominant strategy to not clean. Even if we don’t clean, it is still preferable for them to not clean as well.
How, then, can we overcome this issue? We must find a way to change the utility that our housemate derives from their actions. There are, however, challenges associated with this as well.
The share house — a last remaining relic of the state of nature
One way to adjust the utility of our housemates’ actions is to imbue costs on their actions. The challenge in the context of a share house surrounds the legitimacy of such imposition. After all, no single tenant has any greater claim or say over how things are to operate than any of the other members of the household. Any attempt to demand action from another tenant under the threat of repercussion can always expect the retort of “or what?”. And even if you manage to come up with a threat, there is nothing to say that your housemate won’t just fling something right back at you.
If we do not have material costs we can impose on others, we can always place affective burdens on them. We could always shame our housemates and make them feel bad about not helping out. We could implement a counter for all the times you clean up and they don’t. Mention it to their friends who come over; “hey, sorry about the mess, your friend is a bit of a pig”. Call their parents if need be. Placing a moral cost on inaction is still a cost and may be enough to kickstart them into helping out.
However, sometimes the downfall of our households comes from attempts to try and overcome these free rider problems. If anyone has ever beefed with their housemates or had a house dissolve on bad terms, they know all too well the poignancy of Thomas Hobbes’ remarks about the state of nature being “solitary, poore, nasty, brutish, and short.”
If we follow in Hobbes’ footsteps, we may begin to look to erect a sovereign of sorts. Maybe get the real estate involved as our divine monarchy. There can be regular house inspections, we could even install surveillance cameras to review who is cleaning up and who is not. Free riders beware, the tenancy agreement states that pots and pans may not be soaked overnight unless the tenant wishes to forfeit their lease. Or maybe landlords should spend time regularly living with their tenants so as to pick out and kick out free riders. In any case, tenants recognise the legitimacy of these entities in enforcing costs for misbehaviour. They may think them unjust, but ultimately, they are often respected.
Do I think, then, that this is how this issue should be overcome? Of course not. As a tenant myself, I could not think of anything worse than the picture I have painted above. I would prefer the dirty house than landlords and real estate agents having more influence over my life. Where did this article begin in any case…the cost-of-living crisis.
And this is an important note to pause on. Because while lots of people love the share house life, many have been forced into it and bring with it their own personal circumstances. I have done a lot of free rider bashing in this article, which may make free riding seem like a bad thing . But this is not necessarily the case. As much as they try, some people do not have the time to clean up after themselves as much as they would like. They may be overwhelmed and busy at work or undergoing significant stresses or pressure in other aspects of their life. Your free rider housemate might even be a child who at this point in their life just doesn’t know any better. And in a time of crisis, it may not be the best way forward to try and heap more costs and burdens on our fellow renters.
By making our housemate feel good for their contribution, we can interrupt their free rider tendencies by adjusting the utility associated with each act.
As such, I would like instead to look at another means of changing outcomes: through reward. In this instance, rather than burdening your housemate for not cleaning up after themselves, provide some benefit. It might seem bizarre and burdensome in itself to have to pat your housemate on the back for doing the bare minimum, but if you really value a clean house and you know your housemate is a free rider, then it may be a necessity. A bit of additional praise here and there could mean the difference between a clean house and a dirty one. Consider even offering to help them out in another aspect of the house in exchange for them picking up some slack with the cleaning. I mightn’t say you go as far as giving them treats for completing tasks…however, if it comes to it, and you really want that fresh house look, then please, do what you have to do.
Through positive reinforcement, we attach a private good to cleaning. A private good is something non-rivalrous and excludable. In this case, the private good is the good feeling of contributing to the public good of a clean house. By making our housemate feel good for their contribution, we can interrupt their free rider tendencies by adjusting the utility associated with each act. Ultimately, our aim with positive reinforcement is to increase the utility associated with cleaning to outweigh the utility they would receive from doing whatever other task they’d rather do.
But what about the long term?
Unfortunately, it is likely that positive reinforcement alone will only work in the short term. It’s likely that either your housemate will catch on that you are training them to clean up after themselves, or you will just get sick of the extra work associated with this training. In either case, what we are really looking for is a long term solution to our problem, and positive reinforcement leads us towards where we need to go.
Rather than cheering on your housemate as a means to your own clean freak ends, instead, your positive reinforcement should aim to affirm the positive relationship between housemates. That is, your aim is develop a friendship with your housemate. Friendships with housemates bring with them many opportunities to experience positive utility that far outweigh the negative utility associated with cleaning. Think movie nights, shared cooking, a sense of comfortability, and someone to help get you through those hard days. Through reorientating our priorities towards a friendship, cleaning becomes a gift that housemates share with each other not for the public good of a clean house, but for the friendship and satisfaction associated with meeting each others needs.
This article was written by Luca Bisogni. Luca studies Politics, Philosophy and Economics, which has inspired his interest in Game Theory for this piece. However, he does not play around when it comes to keeping a clean kitchen. He is concerned what his own housemates will think of this piece.
Thank you to Ryann Scott and Hayley Parker for cleaning up this piece and making it presentable for guests.
