Before the widespread use of technology, arranging to meet someone was actually an exercise in coordination. If the time and place were not specific enough, each person would have to make an educated guess about what the other was most likely to do. This ‘coordination game’ was illustrated in class using a simple two-player game matrix where each player gets zero payoff if they choose different strategies, but a positive payoff if they choose the same. However, the payoffs for the two matching pairs may not be equal. If one choice is more beneficial for both players, that choice’s payoff will be greater. For example, if you are arranging to meet your friend at a mall, meeting outside of the GameStop will probably yield a greater “payoff” than meeting outside of Talbots. From a strictly theoretical perspective, there are two equilibria in this game: both of you meet at the Talbots, or both of you meet outside the GameStop. However, if you (as a player in this game) have inside information (like the fact that your friend would rather peruse games than women’s clothes), then you would use this to your advantage and head toward the GameStop. Your friend, given the same information, would probably come to the same conclusion, and thus you would both ‘win’ the game. Thus using outside information known to both of the players, we have effectively chosen one of the Nash Equilibria.

Technology has evolved over the past decade to reduce the chance of losing these types of coordination games. The first of these inventions was the cell phone – instead of having to arrange the meeting a priori on a landline and then rely on logical decision-making once you actually get to the mall, you could call your friend as you’re walking into the mall and find out exactly where he is (thus making your decision much easier). This sort of technology has evolved significantly with the release of the iPhone, and the most recent of these developments is the motivation for this post: Foursquare.

http://mashable.com/2009/07/25/foursquare-app/

Foursquare is an iPhone application that allows you to ‘check in’ to locations as you go about your daily life. Other users of Foursquare can then use the app to two main ends: to see specifically where each of their individual friends is, and (on a larger scale) to see the locations of congregations of the rest of the Foursquare users. Using this information, people can accurately determine where the ‘popular’ places are. Even if there was no function allowing you to see where each of your friends were, you could logically assume that you would have the highest probability of running into at least one of them at a spot where many users are ‘checked in’. Of course, since you can see where your friends are, this makes it very easy to ‘win’ the coordination game when meeting with them – simply go to where they are.

The utility of this app leads to interesting speculation about what the next step in this inventive process would be. Might we one day all have implanted GPS chips that send information to a globally-viewable network? At least we would never have to risk missing a meeting with a friend again.