For many years countries have taken advantage of one another's experiences in formulating social policies and even in designing specific interventions. Often such transfers have occurred on a fairly casual level; sometimes greater rigor has been present. In either case, the goal has been to learn from previous experience-at least to avoid repeating the mistakes of the past. In light of the promise that such intercountry transfers hold, it is somewhat surprising that so little energy has gone into careful analytic work on the behavior of households in differing countries and how they respond...