Abstract: The non-identity problem concerns actions that affect who exists in the future. If such an action is performed, certain people will exist in the future who would not otherwise have existed: they are not identical to any of the people who would have existed if the action had not been performed. Some of these actions seem to be wrong, and they seem to be wrong in virtue of harming the very future individuals whose existence is dependent on their having been performed. The problem arises when it is argued that the actions do not harm these people – because the actions do not make them worse off than they would otherwise be.1 Consider: Radioactive Waste Policy: We are trying to decide whether to adopt a permissive radioactive waste policy. This policy would be less inconvenient to us than our existing practices. If we enact the newly-proposed policy, then we will cause there to be radioactive pollution that will cause illness and suffering. However, the policy will have such significant effects on public policy and industry functioning, that different people will exist in the future depending on whether we enact the policy. Two things should be emphasized. First, the illness and suffering caused will be very serious: deformed babies, children with burns from acid rain, and adults dying young from cancer. Second, the policy will affect who will exist in the future because our present practices invade people’s everyday lives, for example by affecting recycling practices in the home; these practices will change if the policy is adopted. Furthermore, whether we adopt the policy will determine which plants are built where, what jobs are available, and what trucks are on the road. These effects will create small differences in everyone’s lives which ultimately affect who meets whom and who conceives with whom, or at least when people conceive. This affects who exists in the future.