[UTMD-045] Representation Theorems for Path-Independent Choice Rules (by Koji Yokote, Isa E. Hafalir, Fuhito Kojima, M. Bumin Yenmez)

Koji Yokote, Isa E. Hafalir, Fuhito Kojima, M. Bumin Yenmez

Path independence is arguably one of the most important choice rule properties in economic theory. We show that a choice rule is path independent if and only if it is rationalizable by a utility function satisfying ordinal concavity, a concept closely related to concavity notions in discrete mathematics. We also provide a representation result for choice rules that satisfy path independence and the law of aggregate demand.