Diffusion Processes and Event History Analysis

Several authors (e. g., Brüderl, Diekmann, Yamaguchi) derive hazard rate models of event history analysis from social diffusion processes. This paper also focuses on the integration of diffusion research and survival analysis. After a discussion of Diekmann's flexible diffusion model, we present an alternative approach which clarifies theoretical differences between popular rate models (e. g., the exponential model, log-logistic model, sickle model). Specifically, this approach provides a new rationale for the generalised log-logistic model in the sense of a flexible infection process. In cases with bell-shaped duration dependence, it thus allows a test for social contagion as a result of random contacts between actual and potential adopters. An application to divorce data serves as an illustration.

Diffusion processes and event history analysis

Several authors (e.g., Brüderl, Diekmann, Yamaguchi) derive hazard rate models of event history analysis from social diffusion processes. This paper also focuses on the integration of diffusion research and survival analysis. After a discussion of Diekmann's flexible diffusion model, we present an alternative approach which clarifies theoretical differences between popular rate models (e.g., the exponential model, log-logistic model, sickle model). Specifically, this approach provides a new rationale for the generalized log-logistic model in the sense of a flexible infection process. In cases with bell-shaped duration dependence, it thus allows a test for social contagion as a result of random contacts between actual and potential adopters. An application to divorce data serves as an illustration.

Taxation, public services, and the informal sector in a model of endogenous growth

Large informal sectors are an important characteristic of developing countries. The authors build a dynamic model in which the informal sector exists when overregulation (high tax rates and high cost for entering the formal sector) is coupled with an inefficient and corrupt system of compliance control. They consider a production technology in which public services are essential and subject to congestion. The public services are financed by taxes collected from the formal sector. Informal producers evade taxes and, because of their illegal status, can use only some public services, cannot use capital or insurance markets, and are subject to stochastic penalties. The authors find that the relative size of the informal sector is negatively related to the severity of the penalties and positively related to tax rates and the extent of informal use of public services. They also find that economies with larger informal sectors have lower capital return and growth rates because the contribution of public services to productivity decreases with informality. They argue that self-interested bureaucracies create an economic environment that makes informality attractive or simply unavoidable because they profit from the presence of the informal sector.Economic Theory&Research,Banks&Banking Reform,Poverty Assessment,Environmental Economics&Policies,National Governance

The disk-halo interface in edge-on spirals

We are studying the disk-halo interface in several edge-on spiral galaxies through extensive imagery in H(alpha) and other emission lines from Diffuse Ionized Gas (DIG), also referred to as the Warm Ionized Medium (WIM). In addition, for the nearby Sc galaxy NGC4631 we have obtained x-ray observations with ROSAT, to map the distribution of hot (10(exp 6) - 10(exp 7)) gas in the disk and halo. Here we present initial results for two late-type spirals, NGC4244 and NGC4631

Fundamentale Erkenntnisse der Soziologie?

Im Beitrag werden die Ergebnisse eines Forschungsprojekts berichtet, in dessen Rahmen Professorinnen und Professoren der Soziologie gebeten wurden, bis zu fünf ihrer Meinung nach wichtigsten Erkenntnisse der Soziologie anzugeben. Ausgehend von der Feststellung, dass die Leistungsfähigkeit der Soziologie oftmals kritisch beurteilt wird, sollte überprüft werden, ob sich ein geteilter Wissensbestand im Fach identifizieren lässt. Die Auswertung der 62 eingegangenen Antworten ergibt, dass dies bestenfalls auf einer abstrakten Ebene der Fall ist. So werden metatheoretische und methodische Fragestellungen oftmals als wichtig erachtet und es lässt sich eine Orientierung hin zu den Klassikern des Faches konstatieren. Allerdings erstrecken sich die genannten Erkenntnisse auf unterschiedliche Bereiche und auch innerhalb dieser Bereiche zeigt sich eine starke inhaltliche Variabilität. Es wird daher vorgeschlagen, Bemühungen um eine Inventarisierung des soziologischen Wissens wieder aufzugreifen.   This paper presents the results of a research project in which professors of sociology were asked to name up to five most important findings of sociology. We wanted to find out whether there is a stock of sociological knowledge which is widely shared. The analysis of the 62 answers received shows that this is, at most, the case at a quite abstract level. Meta-theoretical and methodological problems are often considered to be important and there is a tendency to emphasize the relevancy of the classics. However, the findings mentioned come from very ifferent areas and there is an enormous diversity in content within these areas. herefore, we propose to pick up efforts to inventory the sociological knowledge

“Two Souls, Alas!, Are Dwelling in My Breast”: A Rational Choice Model of Inner Conflicts

Handlungsentscheidungen können mit inneren Konflikten verbunden sein, die aufgrund der Interaktion verschiedener Grundorientierungen einer Person (z. B. Normen vs. Ressourcen) bestehen. Zielsetzungen des Aufsatzes sind die Rekonstruktion und Analyse solcher Konflikte im Rahmen eines formalen Modells und die Illustration seiner Anwendungen. Diese Modellierung erfolgt auf der Grundlage der (nichtkooperativen) Spieltheorie, die als Teilgebiet der Rational-Choice-Theorie (RCT) explizit mit Konfliktsituationen befasst ist. Der vorliegende Aufsatz steht damit im Gegensatz zu einer insbesondere im deutschsprachigen Raum zu beobachtenden Tendenz, handlungstheoretische Arbeiten in Abgrenzung zur RCT zu verfassen und dabei deren Unzulänglichkeit zu behaupten. Das hier vorgelegte formale Modell zeigt hingegen, dass die RCT flexibel genug ist, um vermeintliche Abweichungen vom traditionellen Kalkül theoretisch zu erfassen. Verdeutlicht wird dies durch modelltheoretische Diskussionen einiger Beispiele (z. B. Low-Cost-Hypothese, Crowding-Out-These, Wahlteilnahme), deren vermeintliche Unvereinbarkeit mit der RCT oft betont wird. Im Rahmen von Modellerweiterungen werden zudem empirisch prüfbare Hypothesen zu Verhaltenseffekten theoretisch begründet.Behavioral decisions may be associated with inner conflicts which reflect the interaction of different personal orientations (e. g., norms vs. resources). The goals of this paper are the reconstruction and analysis of such conflicts in the context of a formal model, whose applications are illustrated. To formulate the model, we use (non-cooperative) game theory as the part of Rational Choice Theory (RCT) which explicitly deals with conflict situations. In contrast to related German work in the sociological theory of action, however, the paper does not emphasize the alleged limitations of RCT. Instead, the formal model shows that RCT is flexible enough to deal with scenarios which, according to sociological critics, would require an alternative theoretical approach (e. g., low-cost situations, crowding-out-hypothesis, electoral participation). Additionally, we offer extensions of the model and develop empirically testable hypotheses withrespect to the behavioral effects of inner conflicts

Who Gets How Much Profit?. A Theory of Exchange Networks and Its Applications

Ausgehend von exogen vorgegebenen Verhandlungsnetzwerken erklären soziologische Tauschtheorien bilaterale Aufteilungen von festgelegten Überschüssen (z. B. Kuchen, Geld) als Folge der strukturellen Einbettung der Tauschpartner. Entsprechend der verfügbaren experimentellen Befunde konzentrieren wir uns auf einfache Tauschnetzwerke und legen ein formales Modell zur Vorhersage der Profitaufteilung in solchen Strukturen vor. Im Gegensatz zu anderen Ansätzen verbinden wir die generalisierte Nash-Verhandlungslösung aus der Spieltheorie mit der Annahme, dass sowohl relationale Eigenschaften als auch Netzwerkpositionen die Tauschergebnisse beeinflussen. Die resultierenden Punktvorhersagen für Profitaufteilungen stimmen gut mit experimentellen Befunden von Cook et al. (1983), Lovaglia et al. (1995), Markovsky, Willer und Patton (1988), Simpson und Willer (1999), Skvoretz und Fararo (1992), Skvoretz und Willer (1993) sowie Yamagishi, Gillmore und Cook (1988) überein.Starting from exogenously given negotiation networks, sociological exchange theories explain bilateral divisions of fixed surpluses (e.g. cake, dollars) as consequences of the partners' structural embeddedness. In accordance with the available experimental evidence, we focus on simple exchange networks and present a formal model for predicting profit distribution from such structures. In contrast to other approaches, we combine the generalized Nash bargaining solution from game theory with the assumption that both relational features and network positions affect exchange outcomes.The resulting point predictions for profit distribution correspond closely with experimental results obtained by Cook et al. (1983), Lovaglia et al. (1995), Markovsky, Willer, and Patton (1988), Simpson and Willer (1999), Skvoretz and Fararo (1992), Skvoretz and Willer (1993) as well as Yamagishi, Gillmore, and Cook (1988)

Millennials and ICT—Findings from the Technology 4 Young Adults (T4YA) project: An Exploratory Study

Information communication technology (ICT) is becoming a pivotal element in the twenty-first century, and while there has been substantial work conducted to understand ICT use by older adults, there is a paucity of knowledge relating to ICT use and behavior by Millennials. The Technology 4 Young Adults (T4YA) study opens the discussion to the barriers and enablers of ICT by Millennials in their day-to-day activities. Eight participants aged 18–33 years were recruited, and open-ended questions were posed to the focus groups participants. A total of three focus groups were conducted, two focus groups were conducted in Pontefract (West Yorkshire, England) and one focus group was conducted in Swansea (West Glamorgan, Wales); all focus groups were recorded and transcribed verbatim. Primary themes included: hardware, privacy issues/concerns, confidence, usability/functionality, day-to-day activities, and content/sharing of information. Day-to-day activities were undertaken primarily on smartphones, such as online banking and shopping, while privacy and trust concerns was a conversation thread throughout the discussions. Further work is needed with larger sample sizes, taking a multi-methods approach to extract quantitative data to underpin qualitative data analysis and frameworks. This exploratory study intersects at the fields of social sciences and human–computer interaction