Research

Potential employers and employees, lawyers and clients, or different business firms often determine their contracts in dyadic negotiations. Exchange theories reflect this pattern. Starting from exogenously given negotiation networks, sociological exchange theories explain bilateral divisions of perfectly divisible surpluses (e.g., cake, dollar) as consequences of the respective partners' structural embeddedness. They thus explain exchange outcomes as the result of bilateral bargaining in networks on the distribution of a surplus. We combine the generalized Nash bargaining solution from cooperative game theory with the assumption that relational and individual features as well as the network positions affect exchange outcomes.

Mutually profitable cooperation is characterized by the fact that the combined efforts of the cooperating parties generate a certain surplus. The production of such a surplus can be framed as a trust problem between two actors. Should an actor provide resources if the other actor can decide on the division of the surplus if it materializes? Under which conditions is trust in a reasonable division of the surplus warranted? We study the effects of “temporal embeddedness” and “network embeddedness”. If both actors interact repeatedly, they can learn about the other actor's trustworthiness from past interactions and third-party resources. And, they can control their relation by facilitating or hampering future exchange (e.g., retaliation, reputation, exit) in which both actors should be interested.

In the absence of manipulation, both the sex ratio at birth and the population sex ratio are remarkably constant in human populations. In large parts of Asia and North Africa, the tradition of son preferences, manifest through sex-selective abortion and discrimination in care practices for girls, has distorted these natural sex ratios. The large cohorts of “surplus” males now reaching adulthood are predominantly of low socioeconomic class, and numerous studies express concerns that their lack of marriageability, and consequent marginalization in society, may lead to antisocial behavior, violence, prostitution, and HIV spread.

Although less dramatic in origin and size, qualitatively similar cohorts of “surplus” men have also emerged in the Neue Bundesländer, where disproportionally many women left rural municipalities during the last three decades since re-unification. We study the effects of these cohorts of “surplus” men by combining micro-level survey data on attitudes with municipality-level data on demographics and economic developments. Using this new panel data set covering all German Landeskreise over the last 30 years, we can estimate the direct demographic effects of “surplus” men on cohabitation, marriage, and divorce rates and the indirect sociological effects of social marginalization on xenophobic attitudes towards foreigners and support for extreme-right parties.

Who cooperates with whom under which conditions? Online experiments are a valuable complement to laboratory experiments and surveys, as they enable to transport a homogeneous decision situation into heterogeneous living conditions. Cooperative outcomes of interactions depend on the personality of the decision maker (e.g., risk attitude, previous experiences), the decision maker’s perception of the interaction partner (e.g., stereotypes leading to positive or negative discrimination), and the type of interaction situation (e.g., altruistic sharing, bargaining, or investing/trusting).