Socionic Multi-Agent Systems Based on Reflexive Petri Nets and Theories of Social Self-Organisation

This contribution summarises the core results of the transdisciplinary ASKO project, part of the German DFG's programme Sozionik, which combines sociologists' and computer scientists' skills in order to create improved theories and models of artificial societies. Our research group has (a) formulated a social theory, which is able to explain fundamental mechanisms of self-organisation in both natural and artificial societies, (b) modelled this in a mathematical way using a visual formalism, and (c) developed a novel multi-agent system architecture which is conceptually coherent, recursively structured (hence non-eclectic) and based on our social theory. The article presents an outline of both a sociological middle-range theory of social self-organisation in educational institutions, its formal, Petri net based model, including a simulation of one of its main mechanisms, and the multi-agent system architecture SONAR. It describes how the theory was created by a re-analysis of some grand social theories, by grounding it empirically, and finally how the theory was evaluated by modelling its concepts and statements.Multi-Agents Systems, Petri Nets, Self-Organisation, Social Theories

Efferent Projections of Prokineticin 2 Expressing Neurons in the Mouse Suprachiasmatic Nucleus

The suprachiasmatic nucleus (SCN) in the hypothalamus is the predominant circadian clock in mammals. To function as a pacemaker, the intrinsic timing signal from the SCN must be transmitted to different brain regions. Prokineticin 2 (PK2) is one of the candidate output molecules from the SCN. In this study, we investigated the efferent projections of PK2-expressing neurons in the SCN through a transgenic reporter approach. Using a bacterial artificial chromosome (BAC) transgenic mouse line, in which the enhanced green fluorescence protein (EGFP) reporter gene expression was driven by the PK2 promoter, we were able to obtain an efferent projections map from the EGFP-expressing neurons in the SCN. Our data revealed that EGFP-expressing neurons in the SCN, hence representing some of the PK2-expressing neurons, projected to many known SCN target areas, including the ventral lateral septum, medial preoptic area, subparaventricular zone, paraventricular nucleus, dorsomedial hypothalamic nucleus, lateral hypothalamic area and paraventricular thalamic nucleus. The efferent projections of PK2-expressing neurons supported the role of PK2 as an output molecule of the SCN

Gender-Specific Effects of Unemployment on Family Formation: A Cross-National Perspective

This paper investigates the impact of unemployment on the propensity to start a family. Unemployment is accompanied by bad occupational prospects and impending economic deprivation, placing the well-being of a future family at risk. I analyze unemployment at the intersection of state-dependence and the reduced opportunity costs of parenthood, distinguishing between men and women across a set of welfare states. Using micro-data from the European Community Household Panel (ECHP), I apply event history methods to analyze longitudinal samples of first-birth transitions in France, Finland, Germany, and the UK (1994-2001). The results highlight spurious negative effects of unemployment on family formation among men, which can be attributed to the lack of breadwinner capabilities in the inability to financially support a family. Women, in contrast, show positive effects of unemployment on the propensity to have a first child in all countries except France. These effects prevail even after ontrolling for labour market and income-related factors. The findings are pronounced in Germany and the UK where work-family conflicts are the cause of high opportunity costs of motherhood, and the gender-specific division of labour is still highly traditional. Particularly among women with a moderate and low level of education, unemployment clearly increases the likelihood to have a first child

Predicting Exchange Rates in Asia: New Insights on the Accuracy of Survey Forecasts

This paper evaluates aggregated survey forecasts with forecast horizons of 3, 12, and 24 months for the exchange rates of the Chinese yuan, the Hong Kong dollar, the Japanese yen, and the Singapore dollar vis-à-vis the US dollar using common forecast accuracy measures. Additionally, the rationality of the exchange rate predictions are assessed utilizing tests for unbiasedness and efficiency. All investigated forecasts are irrational in the sense that the predictions are biased. However, these results are inconsistent with an alternative measure of rationality based on methods of applied time series analysis. Investigating the order of integration of the time series and using cointegration analysis, empirical evidence supports the conclusion that the majority of forecasts are rational. Regarding forerunning properties of the predictions, the results are less convincing, with shorter term forecasts for the tightly managed USD/CNY FX regime being one exception. As one important evaluation result, it can be concluded, that the currency regime matters for the quality of exchange rate forecasts

Job Security and Fertility: Evidence from German Reunification

This paper uses the special occupational status of German civil servants in combination with the unforeseen event of German reunification to study empirically the relationship between job security and fertility. The civil servant-status provides extreme job security as well as good possibilities to combine work and family lives. The fast introduction of the civil service system after reunification represents an exogenous (re-)assignment of individual employment risks in Eastern Germany, and thus allows one to control for occupational self-selection. While no strong evidence for a link between job security and fertility emerges for men, the paper demonstrates a clear link between labor market and demographic outcomes for women, especially in Western Germany and most pronounced for higher educated females between age 25 and 40. This strong relationship is the result of occupational self-selection coupled with a civil servantspecific birth timing pattern and a small causal impact of job security on fertility. It shows that female civil servants are not primarily a selected group of very family oriented individuals, but rather both family as well as career oriented.In dieser Studie wird der Einfluss von Arbeitsplatzsicherheit auf die Wahrscheinlichkeit einer Elternschaft untersucht. Dafür wird zum einen der spezielle Status von Beamten in Deutschland und zum anderen das natürliche Experiment der deutschen Wiedervereinigung genutzt. Der Beamtenstatus bietet ein sehr hohes Maß an Arbeitsplatzsicherheit sowie -flexibilität im Hinblick auf die Vereinbarkeit von Berufs- und Familienleben. Die schnelle Einführung des westdeutschen Beamtensystems in Ostdeutschland nach der deutschen Wiedervereinigung kann als exogene Variation im Hinblick auf die Arbeitsplatzsicherheit der dort betroffenen Individuen gesehen werden. Während sich für Männer kein signifikanter Zusammenhang zwischen Arbeitsplatzsicherheit und Fertilität findet, zeigt sich ein solcher für Frauen, insbesondere in Westdeutschland und am stärksten ausgeprägt für höher qualifizierte Frauen im Alter von 25 bis 40 Jahren. Die starke Korrelation zwischen dem Beamtenstatus und einer zukünftigen Elternschaft bei Frauen ist das Resultat von beruflicher Selbstselektion, eines Beamten-spezifischen Geburten-Timings und einem kleinen direkten Effekt von Arbeitsplatzsicherheit auf die Fertilitätsentscheidung. Weiterführende Analysen legen nahe, dass verbeamtete Frauen keine selektierte Gruppe von überaus familienorientierten Individuen darstellen, sondern dass sie vielmehr sowohl familien- als auch karriereorientiert sind. Die empirischen Ergebnisse deuten folglich darauf hin, dass die Vereinbarkeit von Familie und Beruf für Frauen eine wichtige Rolle bei der Berufswahl spielt