If more moderate Democratic presidential candidates want to stop ideological rival Bernie Sanders from amassing a delegate lead on Super Tuesday, why are they all staying in the race and refusing to coalesce around a single alternative? …
… One answer is that the candidates are stuck in a classic game theory problem. The situation is akin to the prisoner’s dilemma, a game theory principle that describes a situation in which individuals each acting in their own self-interest do not produce an ideal outcome.
“Each candidate is feeling some pressure to get out of the race to help consolidate the non-Sanders and even the non-Bloomberg vote,” said Barry Burden, a political science professor and director of the elections research center at the University of Wisconsin-Madison. “The trouble is that each candidate also has reasons to stay in the race. All are hoping for an unsettled party convention in which neither Sanders nor anyone else walks in with a majority of pledged delegates.”
The classic prisoner’s dilemma example is two co-conspirators who each face a year in prison. If one turns and blames the other, he will go free while the other serves two years — the seemingly best option for self-interested individuals. But if both defect, each will be sentenced to two years in prison, a worse situation.