Distributive justice concerns the socially just allocation of resources, goods and opportunities in a society. It is concerned with how to allocate resources fairly among members of a society, taking into account factors such as wealth, income, and social status. Often contrasted with just process and formal equal opportunity, distributive justice concentrates on outcomes. This subject has been given considerable attention in philosophy and the social sciences. Theorists have developed widely different conceptions of distributive justice. These have contributed to debates around the arrangement of social, political and economic institutions to promote the just distribution of benefits and burdens within a society. Most contemporary theories of distributive justice rest on the precondition of material scarcity. From that precondition arises the need for principles to resolve competing interest and claims concerning a just or at least morally preferable distribution of scarce resources.