Abstract: We examine the interactions that occur between social insurance programs that support disabled persons, using Canadian data. We use a specification that is based on a gravity model from the international trade literature. We find that workers' compensation programs appear to have a large effect on the growth of the Canada/Quebec Pension Plan disability program. However, the other programs (welfare and unemployment insurance) we examine have much weaker effects. We conclude the paper by briefly discussing the implications of our estimates for disability policy.