An experimental study of storable votes

The storable votes mechanism is a voting method for committees that meet periodically to consider a series of binary decisions. Each member is allocated a fixed budget of votes to be cast as desired over the sequence of decisions. This provides incentives for voters to spend more votes on those decisions that matter to them more, typically generating welfare gains over standard majority voting with non-storable votes. Equilibrium strategies have a very intuitive feature-the number of votes cast must be monotonic in the voter's intensity of preferences-but are otherwise difficult to calculate, raising questions of practical implementation. We present experimental data where realized efficiency levels were remarkably close to theoretical equilibrium predictions, while subjects adopted monotonic but off-equilibrium strategies. We are led to conclude that concerns about the complexity of the game may have limited practical relevance.