An alumni network is a formal organization created by a college or a university to maintain relationships with and among their graduates. A number of companies have also established their own so-called alumni networks for former employees. In addition to offering a chance for people to form or sustain social relationships, alumni networks are valuable drivers of economic exchange. People self-select into membership in schools and organizations. They are therefore more likely to share similar backgrounds, values, interests, and abilities with members of their alumni network compared with random strangers, a pattern that sociologists label as “homophily.” Such similarities, as well as the shared educational/employment history, establish a sense that fellow alumni are trustworthy, capable, and worthy of support. Consequently, alumni are willing to hire ...