Simulation Models

A Model of the Gender Cliff in the Relative Contribution to the Household Income

(together with Jan Van Bavel)

In Western countries, the distribution of relative incomes within marriages tends to be skewed in a remarkable way. Husbands usually do not only earn more than their female partners, but there also is a striking discontinuity in their relative contributions to the household income at the 50/50 point: many wives contribute just a bit less than or as much as their husbands, but few contribute more. Our model makes it possible to study a social mechanism that might create this ‘cliff’: women and men differ in their incomes (even outside marriage) and this may differentially affect their abilities to find similar- or higher-income partners. This may ultimately contribute to inequalities within the households that form. The model and associated files make it possible to assess the merit of this mechanism in 27 European countries.

The model code can be downloaded here. The article that describes the development of the model can be obtained here.

Modelling the Social Complexity of Reputation and Status Dynamics

(together with Andreas Flache; model certified to meet the CoMSES Guidelines for Modeling Best-Practices)

This model accompanies the book chapter ‘Grow, André, & Flache, Andreas. 2019. Agent-based computational models of reputation and status dynamics. In F. Giardini & R. P. M. Wittek (Eds.), The Oxford Handbook of Gossip and Reputation (pp. 231–249) Oxford: Oxford University Press.’, in which we illustrate how agent-based computational modelling can be used to study the complex social dynamics that can be involved in the formation of status differentiation.

The model code can be downloaded here. The article that describes the development of the model can be obtained here.

Global Diversity and Local Consensus in Status Beliefs: The Role of Network Clustering and Resistance to Belief Change

(together with Andreas Flache and Rafael Wittek)

Formal models of status construction theory suggest that beliefs about the relative social worth and competence of members of different social groups can emerge from face-to-face interactions in task-focused groups and eventually become consensual in large populations. Our model makes it possible to assess how two extensions of existing models, one at the microlevel and one at the macrolevel, affect this outcome. First, our model incorporates the microlevel behavioral assumption of status construction theory that people can become resistant to belief change, when a belief appears consensual in their local social environment. Second, it integrates the insight that the macrolevel social structure of face-to-face interactions in large populations often is a clustered network structure. We suggest that the combination of network clustering at the macrolevel and resistance to belief change at the microlevel can constrain the diffusion of status beliefs and generate regional variation in status beliefs. The model makes it possible to assess whether this implication follows logically from our theoretical argument.

The model code can be downloaded here. The article that describes the development of the model can be obtained here.

The Reversal of the Gender Gap in Education and Relative Divorce Risks: A Matter of Alternatives in Partner Choice?

(together with Christine Schnor and Jan Van Bavel)

Recent evidence from the United States suggests that the reversal of the gender gap in education was associated with changes in relative divorce risks: hypogamous marriages, where the wife was more educated than the husband, used to have a higher divorce risk than hypergamous marriages, where the husband was more educated, but this difference has disappeared. One interpretation holds that this may result from cultural change, involving increasing social acceptance of hypogamy. We propose an alternative mechanism that need not presuppose cultural change: the gender-gap reversal in education has changed the availability of alternatives from which highly educated women and men can choose new partners. This may have lowered the likelihood of women leaving husbands with less education and encouraged men to leave less educated spouses. The agent-based computational model can be used to assess this mechanism in twelve European national marriage markets.

The model code can be downloaded here. The article that describes the development of the model can be obtained here.

A NetLogo Implementation of "The matching hypothesis reexamined"

This NetLogo model implements the agent-based model described in Kalick, S. M., & Hamilton III, T. E. (1986) "The matching hypothesis reexamined" Journal of Personality and Social Psychology, 51(4):673-682. The 'Info' tab in NetLogo provides information about how to use the model. The model has been implemented as part of the teaching material for the course Introduction to Agent-Based Computational Modelling in Population Studies that took place on 1-5 June 2015 at KU Leuven.

The model code can be downloaded here.

Assortative Mating and the Reversal of Gender Inequality in Education in Europe: An Agent-Based Model

(together with Jan Van Bavel)

While men have always received more education than women in the past, this gender imbalance in education has turned around in large parts of the world. In many countries, women now excel men in terms of participation and success in higher education. This implies that, for the first time in history, there are more highly educated women than men reaching the reproductive ages and looking for a partner. In this agent-based computational model, we explicate the mechanisms that may have linked the reversal of gender inequality in education with observed changes in educational assortative mating. Our model builds on the notion that individuals search for spouses in a marriage market and evaluate potential candidates based on preferences. Based on insights from earlier research, we assume that men and women prefer partners with similar educational attainment and high earnings prospects, that women tend to prefer men who are somewhat older than themselves, and that men prefer women who are in their mid-twenties. We also incorporate the insight that the educational system structures meeting opportunities on the marriage market. The model can be used to study marriage market dynamics in 12 European countries among individuals born between 1921 and 2012.

The model code can be downloaded here. The article that describes the development of the model can be obtained here.

An Agent-Based Model of Status Construction in Task Focused Groups

(together with Andreas Flache and Rafael Wittek; model certified to meet the CoMSES Guidelines for Modeling Best-Practices)

Status beliefs link social distinctions, such as gender and race, to assumptions about competence and social worth. Recent modeling work in status construction theory suggests that interactions in small, task focused groups can lead to the spontaneous emergence and diffusion of such beliefs in larger populations. This earlier work has focused on dyads as the smallest possible groups in which status beliefs might emerge from face-to-face interaction. In today's societies, however, many task focused interactions take place in groups larger than dyads. We therefore have developed an agent-based computational model that enables us to study the emergence of status beliefs in groups larger than dyads. With this model, we can address questions such as: Do basic principles of task focused interaction systematically favor the emergence of status beliefs in groups larger than dyads? Does the time-frame over which small groups interact affect the likelihood with which status beliefs emerge? How does group size affect the emergence of status beliefs?

The model code and a model description based on the ODD protocol can be downloaded here. The article that describes the development of the model can be obtained here.