The Tragedy of the Commons and the Economics of City v. Town

Economic theory is successful because it uses realistic assumptions about the nature of man - that he is rational and will act in his self interest - to coherently explain how we can maintain a fairly efficient, thriving society that can benefit everyone. However, economic theory has also identified certain problems that are part and parcel to its core assumptions, one of which is known as the Tragedy of the Commons. In its classic form, this problem supposes a grazing field shared in common by a number of sheep herders. Because the field is shared jointly, each herder has an incentive to let as many of his sheep graze there as he can, to obtain maximum benefit for himself at a cost that will primarily be absorbed by others. However, because each herder has this identical incentive, each will let as many sheep as he can graze in the field, and soon the field will be destroyed by virtue (or lack thereof) of everyone's self interest.

Basically, the Tragedy of the Commons describes how individual self interest destroys a finite shared resource, despite that its destruction is against each individual's self interest. We see this all the time in everyday life. For instance, at a traffic intersection, it is in everyone's self interest to minimally break the law to obtain an advantage - the pedestrian jaywalks at the last minute, the driver just barely runs a red light, or the traffic heading straight refuses the waiting driver the opportunity to take a left turn across the right of way. The shared resource of limited time to execute a traffic maneuver motivates each man to put himself first and move at the last moment, thus forcing someone else bear the cost. However, because every man thinks that he can be the one to profit from bending the rules in his favor, the corporate traffic flow suffers a gigantic clog of inefficiency because no-one is abiding by the rules. The same man who ran the red light at one intersection will find himself waiting for five minutes to take a left turn at the next, because the drivers coming in the opposite direction - each of them just as rational and self-interested as he - refuse to be the ones to bear the loss and let him take his turn.

Indeed, there are thousands of other day-to-day examples of this scenario. I was at Carnegie Hall on Friday night watching the Cleveland Orchestra perform Shostakovich's Seventh Symphony, and the instant the last chord rang out, about twenty percent of the crowd got up and ran for the door, each one hoping to be the first down the stairs, to the garage, etc. Each of these eager early departers probably knew that his abrupt exit was a bit rude, but trusted that he would be the only one getting up to leave, and that there would be plenty of other people who would stay the extra five minutes for the obligatory extended applause. However, because twenty percent of the audience had that exact same idea, the result was a collective insult to the Cleveland Orchestra that no-one would have wished.

However, the Tragedy of the Commons manifests itself far more often in urban than in small-town life. I don't think this is simply because people in cities are more selfish than people in small towns, but rather because the nature of incentives changes in smaller locales. For instance, a small town citizen may have the same incentive to consume as much as possible of a shared resource, but he also has an incentive weighing in the opposite direction - the incentive not to piss off the other small-town citizens with whom he has to work on a day-to-day basis. This second incentive will often prevail, and he is likely to curb his consumption of the shared resource, knowing that excessive consumption may harm his long-term relationship with his neighbors. But this second incentive is substantially weakened in the city, because there is no long-term relationship with most of the people one interacts with on a daily basis. They are each another face in the crowd who holds little leverage over us - so why not cut them off in traffic, be rude to them at the deli counter, and spit out our wad of gum on their sidewalk? Yet all of this selfishness together can make the city a pretty irritating and unloving place to live.

The prevalence of the Tragedy of the Commons in urban living may lead many to deem small-town life objectively better. But this ignores the upside of the city, the huge economic benefits of the city's vast network of producers and consumers, each of whom can maximize his self-interest through a multivarious and ever expanding number of possible transactions that increase collective wealth. Moreover, as Dr. Keller has pointed out, our final destination is the City. We began in a Garden, but God seeks to bring us to the New Jerusalem, the Heavenly City, where we will ever be enthralled by the excitement of the innumerable blessings of our relationships with one another.

But for now, cities are broken, because the self interest that temporarily sustains our society is only a laughable proxy for love, and its ugly side effects mar every encounter with our fellow urban citizens. It would seem that the solution to the problem is to find a way to introduce the small-town concern for one's neighbor into the city's anonymous sprawl of humanity. This is what Christ asked us to do - "Love thy neighbor as thyself." And who is our neighbor? Christ answered this as well: our neighbor is the man lying beaten and near death on the side of the road, the guy we could cut off in traffic, the post office employee who's taking forever, or the new waitress who just got our order wrong. Our cities will remain dog-eat-dog until we can learn to love these strangers as our brothers and as ourselves.