Consistency in one-sided assignment problems

One-sided assignment problems combine important features of two well-known matching models. First, as in roommate problems, any two agents can be matched and second, as in two-sided assignment problems, the division of payoffs to agents is flexible as part of the solution. We take a similar approach to one-sided assignment problems as Sasaki (Int J Game Theory 24:373–397, 1995) for two-sided assignment problems, and we analyze various desirable properties of solutions including consistency and weak pairwise-monotonicity. We show that for the class of solvable one-sided assignment problems (i.e., the subset of one-sided assignment problems with a non-empty core), if a subsolution of the core satisfies [Pareto indifference and consistency] or [invariance with respect to unmatching dummy pairs, continuity, and consistency], then it coincides with the core (Theorems 1 and 2). However, we also prove that on the class of all one-sided assignment problems (solvable or not), no solution satisfies consistency and coincides with the core whenever the core is non-empty (Theorem 4). Finally, we comment on the difficulty in obtaining further positive results for the class of solvable one-sided assignment problems in line with Sasaki’s (1995) characterizations of the core for two-sided assignment problems.     

„Lola rennt“ oder: „es hätte auch anders kommen können“ – Über den Möglichkeitsraum gruppendynamischer Intervention

A group of eight Trainers for Groupdynamic analyzed their interventions as trainers of Sensitivity-Groups during the last seven years. They used the methodological approach of Sequential Analysis and the model of the groupdynamic space (Amann, Gruppenprozesse verste-hen, 2001, S. 28). This model combines the three elementary polarities shaping the dynamic in T-Groups: belonging (in or out), power (up or down) and nearness (near or far) and supposes that these three polarities form a kind of dynamical “group-space” in which the three dimensions are simultaneously effective. Thus this model avoids a hydraulic understanding of group processes. Taking into account the model of groupdynamical space the group analyzed Trainer-interventions and asked which alternative intervention could have been possible to underline another dimension of the space. In the analysis of interventions they pointed out which of the three dimensions the trainer-intervention was focussing, which consequences this decision had for the group-process and they asked hypothetically which effects another strategy of intervention could have had. Every intervention is the consequence of a particular interpretation of the current group situation. And each decision could have been taken differently by bringing the attention towards another dimension of the groupdynamical space. This is the core-idea of this essay. Years ago a german movie was released with the title “Lola rennt” and it showed three variations of one moment with three entirely different show downs. This idea inspired us to choose the same titel for our reflections about the practice and richness of groupdynamical interventions. This essay is meant as a contribution to a “second order Groupdynamic” which is interested more in the way trainers perceive group processes than in the theory of the group-process itself.     

Getting better or getting worse? Consumer responses to decreasing, constant, and ascending multi-dimensional price profiles

This research investigates consumer preferences for different multi-dimensional price profiles. Drawing on research on price affect, we investigate whether consumers prefer descending monthly installments (e.g., 40, 30, 20, 10) over constant (e.g., 25, 25, 25, 25), or ascending ones (e.g., 10, 20, 30, 40). Results of a field experiment with a sample of 1,628 German car buyers corroborate the hypothesized profile effect. In the experiment, participants were asked to evaluate different finance offers for a new car that all had the same present value but differed in terms of how the installments unfolded over time. Consistent with the hypotheses, decreasing monthly installments are evaluated more favorably than constant installments, which, in turn are evaluated more favorably than ascending installments. Furthermore, the results provide evidence for the underlying process by showing that the impact of different MDP profiles is mediated by positive affect. Finally, it was hypothesized that consumers’ individual differences (i.e., debt aversion, financial expectations, and product category knowledge) would exert a moderating influence on evaluations of different price profiles; these hypotheses, however, were only partially confirmed. Theoretical and managerial implications are discussed.     

New directions for an organised health care system in Germany: The concept of managed care

Against the background of continually rising public sector health costs in Germany, Michael Müller and Klaus Uedelhofen discuss the merits of ‘Managed Care’, a philosophy of organised health care, having its origins in the US in the early 1970s. Managed care is based on networking all separate groups within the healthcare system, standardising the services and performance, and distributing or sharing risks between all parties involved. Advantages, beyond cost reductions, include quality assurance, greater transparency, the establishment of therapy standards and increased responsibility by patients. The outlook for managed care in Germany looks optimistic.     

Quantile smoothing in financial time series

Various parametric models have been designed to analyze volatility in time series of financial market data. For maximum likelihood estimation these parametric methods require the assumption of a known conditional distribution. In this paper we examine the conditional distribution of daily DAX returns with the help of nonparametric methods. We use kernel estimators for conditional quantiles resulting from a kernel estimation of conditional distributions. This work was financially supported by the Deutsche Forschungsgemeinschaft     

REFERENCE POINTS,SOCIAL NORMS,AND FAIRNESS IN CONTRACT RENEGOTIATIONS

How does an ex‐ante contract affect behavior in an ex‐post renegotiation game? We address this question in a canonical buyer–seller relationship with renegotiation. Our paper provides causal experimental evidence that an initial contract has a highly significant and economically important impact on renegotiation behavior that goes beyond the effect of contracts on bargaining threat points. We compare situations in which an initial contract is renegotiated to strategically equivalent bargaining situations in which no ex‐ante contract was written. The ex‐ante contract causes sellers to ask for markups that are 45% lower than in strategically equivalent bargaining situations without an initial contract. Moreover, buyers are more likely to reject given markups in renegotiations than in negotiations. These effects do not depend on whether the contract was written under competitive or monopolistic conditions. Our results provide strong evidence supporting the hypothesis that contracts serve as reference points that shape and coordinate the expectations of the contracting parties.     

<Emphasis Type="Italic">Lothar Krempel</Emphasis>: Visualisierung komplexer Strukturen. Grundlagen der Darstellung mehrdimensionaler Netzwerke. Schriften des Max-Planck-Instituts für Gesellschaftsforschung,Sonderband

Ohne Zusammenfassung     

Parent‐Child Value Similarity: The Role of Zeitgeist

Reporting a study of German 2‐child families, the article focuses on a neglected issue in value transmission studies: contemporaneous societal context. Parent‐child value similarity depends not only on family characteristics but also on zeitgeist, the modal value climate of a society. To evaluate the role of zeitgeist in value transmission, differences in parent‐child value similarity between families agreeing and disagreeing with the zeitgeist are studied, focusing on a core value of modern societies: hierarchic self‐interest. Results show a weak general zeitgeist effect. A family’s relative position vis‐à‐vis the societal value climate, however, is shown to strongly influence intergenerational similarity in hierarchic self‐interest, families distant from the zeitgeist showing a much higher intergenerational value similarity than families close to the zeitgeist.