| We study network formation in a fidelity mating economy with two types of agents (e.g., men and women). Each enjoys having relationships with the opposite type. Having multiple partners is viewed as infidelity, which is punished if detected. Infidelity is punished more severely for women than for men. In Chapter 2, we characterize networks that are likely to arise in this economy using the concept of pairwise stability. We examine their welfare properties as well. Further, we study the asymmetric effects of the diffusion of a random and unexpected information shock. We derive conditions under which such a shock concentrates more among women than men in all pairwise stable networks. We extend the model to economies characterized by female-to-male subjugation, and to hierarchical mating economies. The analysis sheds light on the functioning and outcomes of several real-life markets. In particular, it provides a unified framework for understanding the role of female discrimination in infidelity punishment, market segmentation, and social inequality in gender differences in HIV/AIDS prevalence. Chapter 3, joint with Roberto Serrano, extends the fidelity model to a dynamic environment, in which agents revise the status of their relationships over time, forming new partnerships or severing existing ones, sometimes making mistakes in these decisions. Using a discrete-time Markov matching process, we characterize networks that arise in the very long run. Findings have implications for long-run gender differences in HIV/AIDS prevalence, and for union formation patterns in developed and developing societies. Chapter 4 extends the fidelity model to multi-ethnic societies, to study how ethnic heterogeneity determines the formation of sexual networks, and how these networks, in turn, affect the spread of HIV/AIDS. We find that if such societies are free of strong interethnic conflicts, agents choose their partners from different ethnic groups to hide their infidelity. This optimizing behavior implies a mechanism wherein ethnic heterogeneity encourages sexual infidelity across ethnic groups, giving rise to sexual networks whose configurations make it easier for HIV/AIDS to spread widely. We validate the model using micro-level data from sub-Saharan Africa, and thus offer a new explanation for high HIV/AIDS prevalence in this region. |
