http://www.sciam.com/article.cfm?id=the-doping-dilemma

The Scientific American article “The Doping Dilemma” written by Michael Shermer tells how game theory helps to explain the pervasive abuse of drugs in cycling, as well as baseball and other sports. As we have studied, game theory is the study of how players choose strategies in order to maximize their payoffs by anticipating the strategies of other players. Using prisoner’s dilemma as a model, this article explains why more and more cyclists have been using drugs and hormones to keep up. Analyzing the payoffs seems simple when looked at through this model. The drugs are very effective and many are very difficult to detect. The payoff for using them is basically keeping up with the rest of the cyclists or even winning the races. Once a few riders start cheating by doping, even rule-abiding cyclists must cheat as well. Because of the current penalties in place for cheating, there tends to be a code of silence preventing any of the cyclists to work on reversing the trend of doping. This way, the game becomes a strategic decision, turning the moral choice into an economic one. When the cyclist joins a team, they must decide to follow the drug program and keep up or not to take them which will probably lead to an end in his or her cycling career.
What is interesting about this game is the fact that it starts off with at least one person using the drugs and leads into a cascade where now most of the participants are using the drugs. The fact that the choice even becomes a strategy only happens because of this cascade of people cheating. Other people’s payoffs are affecting the player’s choice. Since they all can’t win a race, if one person is doing better that means others are doing worse.
The problem with this cascade is not only that morality is being compromised, but that players are getting hurt and even dying. One drug in particular that the article mentions is rEPO, which is a naturally occurring hormone that increases production of red blood cells in the marrow, thickening blood and increasing chances of blood clot. This danger has killed several young cyclists who could have had long, healthy lives otherwise. This trend of using drugs in sports clearly needs an end, but in game theory, if no player has anything to gain by unilaterally changing strategies, the game is said to be in a Nash equilibrium. We need to find a way to reverse the equilibrium. To change we must change the payoffs of the game. Payoffs for following the rules must be greater than those of cheating, even when other players are cheating. Players must not feel like suckers for following the rules.
To sum up, this game of using drugs in cycling becomes a cascade when all of the competition is doing one thing that is paying off, more cyclists will do it too, ignoring their own private information that says it is wrong. To quote Vaughters, director of the U.S. cycling team, “these guys are athletes, not criminals,” and they would not be breaking the rules if they didn’t see everyone else doing it and need to in order to maintain their cycling careers. The choice to follow the cascade becomes self defensive in such a competitive sport. One could even argue it as survival.