Abstract

We characterize two lexicographic-type preference extension rules from a set X to the set ? of all orders on this set. Elements of X are interpreted as basic economic policy decisions, whereas elements of ? are conceived as political programs among which a collectivity has to choose through majority voting. The main axiom is called tournament-consistency, and states that whenever majority pairwise comparisons based on initial preferences on X define an order on X, then this order is also chosen by a majority among all other orders in ?. Tournament-consistency thus allows to predict the outcome of majority voting upon orders from the knowledge of majority preferences on their components