We interpret solution rules to a class of simple allocation problems as data on the choices of a policy-maker. We study the properties of rational rules. We show that every rational rule falls into a class of algorithmic rules that we describe. The Equal Gains rule is a member of this class and it uniquely satisfies rationality, continuity, and equal treatment of equals. Its dual, the Equal Losses rule, uniquely satisfies continuity, equal treatment of equals, and two properties that constitute the dual of rationality: translation down and translation up
