  We present a new type of coordination mechanism among multiple agents for the
allocation of a finite resource, such as the allocation of time slots for
passing an intersection. We consider the setting where we associate one counter
to each agent, which we call karma value, and where there is an established
mechanism to decide resource allocation based on agents exchanging karma. The
idea is that agents might be inclined to pass on using resources today, in
exchange for karma, which will make it easier for them to claim the resource
use in the future. To understand whether such a system might work robustly, we
only design the protocol and not the agents' policies. We take a game-theoretic
perspective and compute policies corresponding to Nash equilibria for the game.
We find, surprisingly, that the Nash equilibria for a society of
self-interested agents are very close in social welfare to a centralized
cooperative solution. These results suggest that many resource allocation
problems can have a simple, elegant, and robust solution, assuming the
availability of a karma accounting mechanism.
