Providing Public Goods Without Strong Sanctioning Institutions

This paper proposes a simple mechanism aimed to establish positive contributions to public goods in the absence of powerful institutions to sanction free-riders. The idea of the mechanism is to require players to commit to the public good by paying a deposit prior to the contribution stage. If all players commit in this way, those players who do not contribute their share to the public good forfeit their deposit. If there is no universal commitment, all deposits are refunded and the standard game is played. Given deposits are sufficiently high, prior commitment and full ex post contributions are part of a strict subgame perfect Nash equilibrium for the resulting game. As the mechanism obviates the need for any ex post prosecution of free-riders, it is particularly suited for situations where players do not submit to a common authority as in the case of international agreements

Providing Public Goods Without Strong Sanctioning Institutions

This paper proposes a simple mechanism aimed to establish positive contributions to public goods in the absence of powerful institutions to sanction free-riders. The idea of the mechanism is to require players to commit to the public good by paying a deposit prior to the contribution stage. If all players commit in this way, those players who do not contribute their share to the public good forfeit their deposit. If there is no universal commitment, all deposits are refunded and the standard game is played. Given deposits are sufficiently high, prior commitment and full ex post contributions are part of a strict subgame perfect Nash equilibrium for the resulting game. As the mechanism obviates the need for any ex post prosecution of free-riders, it is particularly suited for situations where players do not submit to a common authority as in the case of international agreements.public goods; cooperation; institutions; Climate-Change Treaties

Minimum Participation Rules for the Provision of Public Goods

This paper considers the endogenous formation of an institution to provide a public good. If the institution governs only its members, players have an incentive to free ride on the institution formation of others and the social dilemma is simply shifted to a higher level. Addressing this second-order social dilemma, we study the effectiveness of three different minimum participation requirements: 1. full participation / unanimity rule; 2. partial participation; 3. unanimity first and in case of failure partial participation. While unanimity is most effective once established, one might suspect that a weaker minimum participation rule is preferable in practice as it might facilitate the formation of the institution. The data of our laboratory experiment do not support this latter view, though. In fact, weakening the participation requirement does not increase the number of implemented institutions. Thus, we conclude that the most effective participation requirement is the unanimity rule which leaves no room for free riding on either level of the social dilemma.public goods, coalition formation, endogenous institutions

Ward identities in N=1\mathcal{N}=1 supersymmetric SU(3) Yang-Mills theory on the lattice

The introduction of a space-time lattice as a regulator of field theories breaks symmetries associated with continuous space-time, i.e.\ Poincar{\'e} invariance and supersymmetry. A non-zero gluino mass in the supersymmetric Yang-Mills theory causes an additional soft breaking of supersymmetry. We employ the lattice form of SUSY Ward identities, imposing that their continuum form would be recovered when removing the lattice regulator, to obtain the critical hopping parameter where broken symmetries can be recovered.Comment: Presented at Lattice 2017, the 35th International Symposium on Lattice Field Theory at Granada, Spain (18-24 June 2017

Supermultiplets in N=1 SUSY SU(2) Yang-Mills Theory

We study $\mathcal{N}=1$ supersymmetric Yang-Mills theory (SYM) on the lattice. The non-perturbative nature of supersymmetric field theories is still largely unknown. Similarly to QCD, SYM is confining and contains strongly bound states. Applying the variational method together with different smearing techniques we extract masses of the lightest bound states such as gluino-glue, glueball and mesonic states. As these states should form supermultiplets, this study allows to check whether SYM remains supersymmetric also on the quantum level.Comment: Presented at Lattice 2017, the 35th International Symposium on Lattice Field Theory at Granada, Spain (18-24 June 2017

Improved results for the mass spectrum of N=1 supersymmetric SU(3) Yang-Mills theory

This talk summarizes the results of the DESY-M\"unster collaboration for $\mathcal{N}=1$ supersymmetric Yang-Mills theory with the gauge group SU(3). It is an updated status report with respect to our preliminary data presented at the last conference. In order to control the lattice artefacts we have now considered a clover improved fermion action and different values of the gauge coupling.Comment: Presented at Lattice 2017, the 35th International Symposium on Lattice Field Theory at Granada, Spain (18-24 June 2017

Do Sugar-Sweetened Beverages Increase Fasting FGF21 Irrespective of the Type of Added Sugar? A Secondary Exploratory Analysis of a Randomized Controlled Trial.

Human fibroblast growth factor 21 (FGF21) is a multifaceted metabolic regulator considered to control sugar intake and to exert beneficial effects on glucose and lipid metabolism. Elevated serum FGF21 levels are associated with metabolic syndrome, suggesting a state of FGF21 resistance. Further, given the evidence of a hepatic ChREBP and FGF21 signaling axis, it can be assumed that SSBs containing fructose would possibly increase FGF21 concentrations. We investigated the effects of sugar-sweetened beverage (SSB) consumption on fasting FGF21 levels in healthy, lean men, discriminating the effects of glucose, fructose, and their disaccharide sucrose by secondary data analysis from a randomized controlled trial. Seven weeks of daily SSB consumption resulted in increased fasting FGF21 in healthy, lean men, irrespective of the sugar type. Medians of ΔFGF21 between post-SSB intervention values (week 7) and no-intervention period values (IQR) in pg/mL were: glucose 17.4 (0.4-45.8), fructose 22.9 (-8.6-35.1), and sucrose 13.7 (2.2-46.1). In contrast, this change in FGF21 concentration was only 6.3 (-20.1-26.9) pg/mL in the control group. The lack of a fructose-specific effect on FGF21 concentrations is contrary to our assumption. It is concluded that SSB intake may impact FGF21 concentrations and could contribute to the increased FGF21 concentrations observed in subjects suffering from metabolic syndrome that is possibly associated with decreased FGF21 responsiveness

Do Sugar-Sweetened Beverages Increase Fasting FGF21 Irrespective of the Type of Added Sugar? A Secondary Exploratory Analysis of a Randomized Controlled Trial

Human fibroblast growth factor 21 (FGF21) is a multifaceted metabolic regulator considered to control sugar intake and to exert beneficial effects on glucose and lipid metabolism. Elevated serum FGF21 levels are associated with metabolic syndrome, suggesting a state of FGF21 resistance. Further, given the evidence of a hepatic ChREBP and FGF21 signaling axis, it can be assumed that SSBs containing fructose would possibly increase FGF21 concentrations. We investigated the effects of sugar-sweetened beverage (SSB) consumption on fasting FGF21 levels in healthy, lean men, discriminating the effects of glucose, fructose, and their disaccharide sucrose by secondary data analysis from a randomized controlled trial. Seven weeks of daily SSB consumption resulted in increased fasting FGF21 in healthy, lean men, irrespective of the sugar type. Medians of ΔFGF21 between post-SSB intervention values (week 7) and no-intervention period values (IQR) in pg/mL were: glucose 17.4 (0.4-45.8), fructose 22.9 (-8.6-35.1), and sucrose 13.7 (2.2-46.1). In contrast, this change in FGF21 concentration was only 6.3 (-20.1-26.9) pg/mL in the control group. The lack of a fructose-specific effect on FGF21 concentrations is contrary to our assumption. It is concluded that SSB intake may impact FGF21 concentrations and could contribute to the increased FGF21 concentrations observed in subjects suffering from metabolic syndrome that is possibly associated with decreased FGF21 responsiveness