 Third, those presently alive can affect the very existence of future people (whether or not future people will exist), the number of future people (how many future people will exist), and the identity of future people (who will exist). In short: future people’s existence, number, and specific identity depend (are contingent) upon currently living people’s decisions and actions. A decision taken by present generations could conceivably result in the termination of human life (see, e.g., Scheffler 2013; Mulgan 2015; McKinnon 2017); there is a long tradition of institutionalized population policy whose goal is to control the size of future generations (see, e.g., McMahan 1981); and, more prosaically, a couple can certainly decide whether or not to have children (see  §2.2  and  §3.2).  Furthermore, many of our decisions have indirect effects on how many people will live and who they are, for many of our decisions affect who meets whom and who decides to have children with whom. To explain such “different people choices”, Parfit adopts the genetic identity view of personal identity: the identity of a person is at least in part constituted by the DNA the person has as a result of which ovum was fertilized by this or that spermatozoon in the creation of this person. Our actions thus have an effect on the genetic identity of future people in so far as they affect from which particular pairs of cells future people will grow—and any action that affects people’s reproductive choices, directly or indirectly, will do that. Many of our actions in fact have an indirect effect on when future people will be conceived. If we decide between two long-term policies regarding the use of natural resources, for example, we know that depending on which we choose, different (and most likely also a different number of) future people will come into existence. For example, the European Commission finds that more than one million babies may have been produced as a result of the Erasmus Programme (the European Community Action Scheme for the Mobility of University Students, and with more than three million students participating since 1987), most of who would very likely not have come to existence without at least one of their parents participating in the Programme (European Commission 2014: 130–131).