Consider this situation: You are given the choice between personally receiving a small prize or giving your children a much larger prize. Whatever you choose, it is possible that your children will one day face a similar choice. Being your children, they resemble you in many ways and are more likely than not to choose similarly to you. Its not quite a Parfit's Hitchhiker even from your childrens' perspective - the consequences of their choice are in the past, not the future - but it's close, and the result is the same.