Bicameralism and the Core: An Experimental Test

While the primary problem confronting democratic theorists in the past several decades has been majority rule instability, recent formal results suggest that this problem is diminished by long-standing constitutional provisions such as bicameralism. Bicameralism should theoretically be much more likely to create a set of stable and undominated outcomes—a core. This paper reports a series of experiments testing whether individuals partitioned into two chambers do in fact behave as the formal theory of bicameralism predicts. In two sets of trials, the outcome chosen under a given bicameral partition is almost always in the bicameral core for that partition, and a change in the bicameral partition has a statistically significant impact on the choice of outcome.