You may have heard about a huge snowstorm in the American Midwest. I am in the middle of it.
When one is shoveling snow for hours, one has a lot of time to think. Early this morning, I pondered the Game Theory of Snow Shoveling.
This game has two actors: the Shoveler (me), and the Neighbor With the Big Snowblower.
Consider:
- There are three important zones in this game: the Sidewalk, the Driveway, and the Driveway Base.
- The Neighbor is under no obligation to help the Shoveler, but for reasons of altruism and societal pressures, there is a percentage chance that he will help the Shoveler at some point in the game.
- The most difficult snow to remove is Base snow--it has been piled up by snowplows, making it very tall and very dense. The easiest snow to remove is Sidewalk--there is less of it than there is regular Driveway snow.
- I am selfishly most interested in the condition of my driveway. Since the Base snow is the most difficult to remove, and only gets harder the longer I wait (it gets denser and denser as it piles up and solidifies under its own weight), I am inclined to attack it first, when I am freshest and the Base is as easy as it's ever going to get.
- However, as the Base snow is really difficult for a Shoveler to attack, it's the one I would most like the Neighbor to help with. On the other hand, if I delay it and the Neighbor opts not to help me in this stage of the game, I will be worse off in later stages (since the Base will get more and more difficult.)
- Although my personal interest is in the Driveway and Base, societally (and in most municipalities, legally) I am obligated to clear the Sidewalk.
- But because the sidewalk is a common good, Neighbor is relatively more likely to help me with that than with Driveway or Base.
- By extension, if I am a good citizen, I will clear my sidewalk first. But in so doing, I make it much less likely that I will actually get any aid whatsoever from Neighbor.
End result: I focused on the base of my driveway and left the sidewalk for later. When I came back out after a much-needed break, about 60% of my sidewalk had been cleared by neighbor snowblowers. Another victory for game theory!