Agent-based Computational Models and Social Interactions in Demography
Agent based models of the marriage market
Alexia Fürnkranz-Prskawetz, Thomas Fent and Belinda Aparicio Diaz
Marriage patterns have been studied from two different perspectives in the literature. On the one side, demographers and sociologists have focused on explaining and modelling important stylized facts such as the typical shape of age-at-marriage curves; their analytical strategies usually relied on mathematical and statistical macro-level models. Psychologists and economists have focused on studying and modelling the process of partner search; micro-level assumptions were usually at the heart of this approach. Recently, agent-based modelling has allowed to build models that account for macro-level marriage patterns starting from plausible micro-level assumptions and allowing for the interactions between potential partners that typically take place in the marriage market. In this project we build a marriage model based on the micro-level, including social influence as the key force driving the process of getting married. Our aim is to have the typical macro–level shape of age-at-marriage patterns to emerge ``from the bottom up'', as an outcome of our assumptions on individual behaviour and social interactions. The main benchmark against which we test our model is the shape of the age-at-marriage hazard function.
Dynamische Segregation, ' deconcentration of the poor'
Gustav Feichtinger
Eine interessante Aufgabe der US-Siedungspolitik ist die Verhinderung der Ghetto-Bildung armer Haushalte. Dazu werden letztere in wohlhabendere Viertel umgesiedelt, ohne dass die "Flucht" von Mittelklasse-Familien überhand nimmt. Auf diese Weise kommen zugezogene arme Familien weniger mit Kriminalität in Berührung, haben besseren Zugang zur Ausbildung ihrer Kinder und zum Job-Markt aufgrund sozialer Netzwerk-Effekte. Eine Modellanalyse der Dekonzentration von Arm-Reich zeigt mehrfache Gleichgewichte, Geschichtsabhängigkeit der Entwicklungspfade und Unstetigkeiten der Steuerungsinstrumente. Diese Tatsache birgt für die Politik die Gefahr, unangemessene sozialpolitische Maßnahmen zu setzen. Die Vermei-dung solcher planerischen Irrtümer angesichts sozialer Interaktionen ist ein Hauptziel des Projekts. Die bisherigen Arbeiten resultierten in mehreren Publikationen.
Evolution of norms for age at marriage
Alexia Fürnkranz-Prskawetz, Thomas Fent and Belinda Aparicio Diaz
We analyse an agent-based model designed to understand the dynamics of the intergenerational transmission of age-at-marriage norms. A norm in this context is an acceptable age interval to get married. It is assumed that this age-interval is defined at the individual level and the individuals' age-at-marriage norms are transmitted from parents to their children. We compare four different transmission mechanisms to investigate the long-term persistence or disappearance of norms under different regimes of transmission. Heterogeneity with respect to age and sex is explicitly taken into account. Moreover, the timing of union formation and fertility is also included in the model. To create a more realistic model of the evolution of age norms the characteristics of the agents are extended, some new parameters are added to the model, and the norms are split into two sex-specific age-at-marriage norms. A comparison of the results with those of the original model gives insights how additional characteristics and new parameters can influence the evolution of age-at-marriage norms.
Social Status and the Quantity-Quality-Trade-off of Children
Alexia Fürnkranz-Prskawetz, Maria Winkler-Dworak
The aim of the project is to embed social status in economic models of fertility. In contrast to the existing literature (e.g. Palivos 2000), in this project social norms or social status are modelled via the quality rather than via the quantity of children. In particular, we assume that individuals optimise their utility by optimally deciding over their consumption, their number of children, and the investment into education of their children. Moreover, we assume that raising children requires time costs of the parents, which could be spent on the labour market otherwise, and educational costs. In line with de la Croix and Doepke (2003), we postulate that education is provided by teachers and not by the parents. In addition, we assume that the utility of children also depends on social status. In particular, we define social status as the human capital of the own children relative to the average human capital of the children in the economy. We introduce a parameter, which governs how much weight is put on status considerations.
Our aims are twofold: first we will investigate the effect of the status considerations on the equilibrium consumption, the equilibrium number of children and their human capital. Indeed, first results show that incorporating social status in such a way may lead to a decrease of the number of children, which exceeds the classical trade-off between quantity and quality of children. This finding may represent a further possible explanation of the so-called lowest-low fertility in many industrialised countries. On the other hand, we aim to study whether status consideration can generate or amplify human capital growth.
References:
- Palivos, Theodore (2001) Social norms, fertility and economic development. Journal of Economic Dynamics & Control 25: 1919-1934.
- de la Croix, David and Matthias Doepke (2003) Inequality and growth: why differential fertility matters. American Economic Review 93 (4: 1091-1113.