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 - TY - JOUR AU - Schmitz, Hendrik ID - 5239 JF - Patient Gesundheitswesen – Mission 2030 Unsere gemeinsame Verantwortung die Zukunft zu gestalten TI - Rationalisierung vs. Rationierung Ist die Rationierung unvermeidbar? ER - TY - JOUR AU - Schmitz, Hendrik AU - Westphal, Matthias ID - 2957 JF - Journal of Health Economics TI - Short-and medium-term effects of informal care provision on female caregivers’ health VL - 42 ER - TY - JOUR AU - Brangewitz, Sonja AU - Gamp, Jan-Philip ID - 2522 IS - 3 JF - Economic Theory SN - 0938-2259 TI - Competitive outcomes and the inner core of NTU market games VL - 57 ER - TY - JOUR AU - Gries, Thomas AU - Grundmann, Rainer ID - 2819 IS - 4 JF - Journal of Population Economics TI - Trade and fertility in the developing world: the impact of trade and trade structure VL - 27 ER - TY - JOUR AU - Gries, Thomas AU - Dung, Ha Van ID - 2842 JF - Modern Economy TI - Household Savings and Productive Capital Formation in Rural Vietnam: Insurance vs. Social Network VL - 5 ER - TY - JOUR AB - This paper studies welfare consequences of consumer-side market transparency with endogenous entry of firms. Different from most studies, we consider the unique symmetric entry equilibrium, which is in mixed strategies. We identify two effects of market transparency on welfare: a competition effect and a novel market-structure effect. We show, surprisingly, that for almost all demand functions the negative market-structure effect eventually dominates the positive competition effect as the market becomes increasingly transparent. Consumer-side market transparency can therefore be socially excessive even without collusion. The only exception among commonly used demand functions is the set of constant demand functions. AU - Gu, Yiquan AU - Hehenkamp, Burkhard ID - 2709 IS - 2 JF - Journal of Institutional and Theoretical Economics JITE SN - 0932-4569 TI - Too Much of a Good Thing? Welfare Consequences of Market Transparency VL - 170 ER - TY - JOUR AB - How is collective defence by players affected when they face a threat from an intelligent attacker rather than a natural threat? This paper analyses this question using a game-theoretic model. Facing an intelligent attacker has an effect if players move first and visibly set their defence strategies, thereby exposing any players who do not defend, and if the attacker is, moreover, not able to commit to a random attack. Depending on the parameters of the game, the presence of an intelligent attacker either increases the probability that players jointly defend (where such joint defence either does or does not constitute a utilitarian optimum), or decreases the probability that players jointly defend (even though joint defence is a utilitarian optimum). AU - De Jaegher, Kris AU - Hoyer, Britta ID - 1923 IS - 5 JF - Defence and Peace Economics SN - 1024-2694 TI - Collective action and the common enemy effect VL - 27 ER - TY - JOUR AU - Schmitz, Hendrik AU - Augurzky, B. AU - Roppel, U. ID - 5241 JF - RWI Position TI - Kehrtwende in der Gesundheitspolitik - Unnötige Abkehr von einer erfolgreichen Reform zur Finanzierung der gesetzlichen Krankenversicherung VL - 59 ER - TY - JOUR AU - Mayrhofer, Thomas AU - Schmitz, Hendrik ID - 2959 IS - 3 JF - Journal of Population Economics TI - Testing the relationship between income inequality and life expectancy: A simple correction for the aggregation effect when using aggregated data VL - 27 ER - TY - JOUR AU - Keese, Matthias AU - Schmitz, Hendrik ID - 2960 IS - 3 JF - Review of Income and Wealth TI - Broke, ill, and obese: is there an effect of household debt on health? VL - 60 ER -