THE STABILITY OF CORE AND PERIPHERAL NETWORKS OVER TIME

This article uses data on 'network instability' to show how difference s across multiple measurements on the membership of personal networks can yield important insights into the nature of these networks. The da ta come from it sample of 234 recent widows, aged 59-85, who completed seven interviews about their networks over a I-year period. We use th ese data to investigate the stability of both overall networks and ind ividual ties, as well as the linkage between the stability of individu al ties and the stability of the network's aggregate properties. We fi nd that instability in these networks is best thought of in terms of a n underlying 'core-periphery' structure, whereby some network members are likely to be named repeatedly (the core), while others are relativ ely unlikely to appear in any given elicitation of the network (the pe riphery). We explore the implications of this core-periphery structure for cross-sectional elicitations of personal networks.