A new congruence axiom and transitive rational choice

Rationality in choice theory has been an abiding concern of decision theori sts. X rationality postulate of considerable significance in the literature is the weak congruence axiom of Richter and Sen. It is well known that in discrete choice contexts of the classical type (i.e. all non-empty finite s ubsets of a given set comprise the set of choice problems) this axiom is eq uivalent to full rationality. The question is: will a weakening of the weak congruence axiom suffice to imply full rationality? This is the question w e take up in this paper. We propose a weaker new congruence axiom which alo ng with the Chernoff axiom implies full rationality. The two axioms are ind ependent. We also study interesting properties of these axioms and their in terconnections through examples.