To ascertain social network ties, a separate dataset was created that linked individuals through self-described social ties collected at each of the seven waves of the study. Thus, it is possible to know which participants have a relationship (e.g., spouse, sibling, friend, co-worker, neighbor) with other participants; and these ties could be observed to change across time. Each link between two people might be identified by either party identifying the other. This observation is most relevant to the “friend” link, as it is possible to make this link either when A nominates B as a friend, or when B nominates A. Complete records of participants’ and their contacts’ address in each wave since 1971 were also used in the analyses, though it is important to note that we do not have any information about relationships that participants did not report. At each wave, it was possible to determine (1) who is whose neighbor, and (2) the geographical distance between individuals (10, 17). Table 1 provides descriptive statistics regarding the 5,124 principals in our sample.
