The "Wedding-Ring"

Abstract

Abstract In this paper we develop an agent-based marriage model based on interaction. We build an population of interacting agents whose chances of marrying depend on availability of partners, and whose willingness to marry depends on share of in their network who are already married. We then let typical aggregate age pattern of marriage emerge from The results of our simulation show that micro-level hypotheses founded on existing theory and evidence on interaction can reproduce age-at-marriage patterns with both realistic shape and realistic micro-level dynamics. (ProQuest: ... denotes formulae omitted.) 1. Introduction In and behavioral sciences, timing of marriage has been studied from two different perspectives. On one side, demographers and sociologists have focused on explaining and modeling important stylized facts such as typical shape of age-at- marriage curves; their analytical strategies have usually relied on mathematical and statistical macro-level models. On other side, psychologists and economists have focused on studying and modeling process of partner search; micro-level assumptions have usually been at heart of this approach. More recently, agent-based modeling has been proposed as a convenient approach to build models that account for macro-level marriage patterns while starting from plausible micro-level assumptions. This is particularly important in marriage models because agent-based models allow for realistic hypotheses on interaction between heterogeneous potential partners that typically takes place in marriage market (Billari et al., 2003; Todd and Billari, 2003; Simao and Todd, 2003; Todd et al., 2005; Aparicio Diaz and Fent, 2006). The study of emergence of macro-level outcomes from micro-level models that contains interactions allows to bridge micro- and macro-level perspective from the bottom-up. This approach is very widely used in agent-based models, for which application to demographic choices has been recently advocated (Billari and Prskawetz, 2003). The macro-level outcome that has been studied most is age pattern of marriage, which demographers have shown as being characterized by constant features over time and space (Coale, 1971; Coale and McNeil, 1972). Partnership formation is by definition interaction itself. In contemporary societies, great majority of potential partners meet each other, talk to each other, have sex before cohabiting or getting married. Nevertheless, important scientific evidence signals that interactions taking place in marriage market are not limited to those between potential partners. Indeed, study of impact of what relevant others think and do on key decisions concerning our lives - such as getting married and having children - has emerged as an important field of research (Bongaarts and Watkins, 1996). Montgomery and Casterline (1996; 1998) identify two distinct processes through which matter: first, social learning, reflecting acquisition of information in a network; second, social influence, reflecting power might exercise over an individual through authority, deference, and conformity pressure. While most results on learning and influence refer to contraceptive and fertility choices in developing world, recent evidence from qualitative surveys shows that both learning and influence are among important factors in decision to get married in a contemporary society (Bernardi, 2003). What do is a key mechanism in influential macro-level diffusion model of age-at-marriage proposed by Hernes (1972). Hernes' model is built on assumption that a diffusion process takes place within a cohort of individuals, with share of married peers influencing propensity to marry. …