TY - JOUR AB - We construct two-player two-strategy game-theoretic models of by-product mutualism, where our focus lies on the way in which the probability of cooperation among players is affected by the degree of adversity facing the players. In our first model, cooperation consists of the production of a public good, and adversity is linked to the degree of complementarity of the players׳ efforts in producing the public good. In our second model, cooperation consists of the defense of a public, and/or a private good with by-product benefits, and adversity is measured by the number of random attacks (e.g., by a predator) facing the players. In both of these models, our analysis confirms the existence of the so-called boomerang effect, which states that in a harsh environment, the individual player has few incentives to unilaterally defect in a situation of joint cooperation. Focusing on such an effect in isolation leads to the "common-enemy" hypothesis that a larger degree of adversity increases the probability of cooperation. Yet, we also find that a sucker effect may simultaneously exist, which says that in a harsh environment, the individual player has few incentives to unilaterally cooperate in a situation of joint defection. Looked at in isolation, the sucker effect leads to the competing hypothesis that a larger degree of adversity decreases the probability of cooperation. Our analysis predicts circumstances in which the "common enemy" hypothesis prevails, and circumstances in which the competing hypothesis prevails. AU - De Jaegher, Kris AU - Hoyer, Britta ID - 1922 JF - Journal of Theoretical Biology SN - 0022-5193 TI - By-product mutualism and the ambiguous effects of harsher environments – A game-theoretic model VL - 393 ER - TY - JOUR AU - Schiele, Valentin AU - Schmitz, Hendrik ID - 2688 JF - Journal of Health Economics TI - Quantile treatment effects of job loss on health VL - 49 ER - TY - JOUR AU - Herr, Annika AU - Nguyen, Thu-Van AU - Schmitz, Hendrik ID - 3083 IS - 10 JF - Health Policy TI - Public reporting and the quality of care of German nursing homes VL - 120 ER - TY - JOUR AU - Göpffarth, Dirk AU - Kopetsch, Thomas AU - Schmitz, Hendrik ID - 2956 IS - 7 JF - Health economics TI - Determinants of regional variation in health expenditures in Germany VL - 25 ER - TY - JOUR AU - Decker, Simon AU - Schmitz, Hendrik ID - 15259 JF - Journal of Health Economics SN - 0167-6296 TI - Health shocks and risk aversion VL - 156-170 ER - TY - JOUR AU - Gries, Thomas AU - Naudé, Wim AU - Bilkic, Natascha ID - 2815 JF - The Quarterly Review of Economics and Finance TI - Playing the Lottery or Dressing Up? A Model of Firm-Level Heterogeneity and the Decision to Export VL - 58 ER - TY - JOUR AU - Gries, Thomas AU - Feng, Yuanhua AU - Guo, Zhichao ID - 2816 IS - 2 JF - China Agricultural Economic Review TI - Changes of China’s agri-food exports to Germany caused by its accession to WTO and the 2008 financial crisis VL - 7 ER - TY - JOUR AU - Gries, Thomas AU - Palnau, Irene ID - 3295 IS - 4 JF - Peace Economics, Peace Science and Public Policy TI - Sustaining Civil Peace: a configurational comparative analysis VL - 21 ER - TY - JOUR AU - Gries, Thomas AU - Meierrieks, Daniel AU - Redlin, Margarete ID - 3296 IS - 1 JF - Oxford Economic Papers TI - Oppressive Governments, Dependence on the United States and Anti-American Terrorism VL - 67 ER - TY - JOUR AB - In the framework of spatial competition, two or more players strategically choose a locationin order to attract consumers. It is assumed standardly that consumers with the same favorite location fully agree on the ranking of all possible locations. To investigate the necessity of this questionable and restrictive assumption, we model heterogeneity in consumers’ distance perceptions by individual edge lengths of a given graph. A profile of location choices is called a “robust equilibrium” if it is a Nash equilibrium in several games which differ only by the consumers’ perceptions of distances. For a finite number of players and any distribution of consumers, we provide a full characterization of all robust equilibria and derive structural conditions for their existence. Furthermore, we discuss whether the classical observations of minimal differentiation and inefficiency are robust phenomena. Thereby, we find strong support for an old conjecture that in equilibrium firms form local clusters. AU - Buechel, Berno AU - Röhl, Nils ID - 491 IS - 2 JF - European Journal of Operational Research TI - Robust Equilibria in Location Games VL - 240 ER -