On the formation of coalitions to provide public goods: Experimental evidence from the lab

The provision of public goods often relies on voluntary contributions and cooperation. While most of the experimental literature focuses on individual contributions, many real-world problems involve the formation of institutions among subgroups (coalitions) of players. International agreements serve as one example. This paper experimentally tests theory on the formation of coalitions in different institutions and compares those to a voluntary contribution mechanism. The experiment confirms the rather pessimistic conclusions from the theory: only few players form a coalition when the institution prescribes the full internalization of mutual benefits of members. Contrary to theory, coalitions that try to reduce the freeriding incentives by requiring less provision from their members, do not attract additional members. Substantial efficiency gains occur, however, both along the extensive and intensive margin when coalition members can each suggest a minimum contribution level with the smallest common denominator being binding. The experiment thereby shows that the acceptance of institutions depends on how terms of coalitions are reached. --public goods,institutions,coalition formation,cooperation

On the formation of coalitions to provide public goods : experimental evidence from the lab

The provision of public goods often relies on voluntary contributions and cooperation. While most of the experimental literature focuses on individual contributions, many real-world problems involve the formation of institutions among subgroups (coalitions) of players. International agreements serve as one example. This paper experimentally tests theory on the formation of coalitions in different institutions and compares those to a voluntary contribution mechanism. The experiment confirms the rather pessimistic conclusions from the theory: only few players form a coalition when the institution prescribes the full internalization of mutual benefits of members. Contrary to theory, coalitions that try to reduce the freeriding incentives by requiring less provision from their members, do not attract additional members. Substantial efficiency gains occur, however, both along the extensive and intensive margin when coalition members can each suggest a minimum contribution level with the smallest common denominator being binding. The experiment thereby shows that the acceptance of institutions depends on how terms of coalitions are reached

The impact of burden sharing rules on the voluntary provision of public goods

We investigate how burden sharing rules may impact the voluntary provision of a public good which generates heterogeneous benefits to agents. We compare different rule-based contribution schemes that are based on the principle of the smallest common denominator: all agents can suggest a minimum provision level of the public good that is allocated across agents according to some predetermined rule. We find that rule-based contribution schemes significantly increase payoff levels relative to the VCM. Important differences exist between the rules. Contrary to theory predictions, the equal-payoff rule Pareto-dominates all other rules. This also holds relative to a scheme where different types of players separately can determine their minimum contribution levels. Our results lend insights into the efficient institutional design for voluntary private provision of public goods, and how burden sharing rules interact with efficiency when agents are heterogeneous

On the performance of rule-based contribution schemes under endowment heterogeneity

We experimentally test different rule-based contribution mechanisms in a repeated 4-player public goods game with endowment heterogeneity and compare them to a VCM, distinguishing between a random- and an effort-based allocation of endowments. We find that endowment heterogeneities limit the efficiency gains from minimum contribution rules under random allocation. Under effort-based allocations, substantial efficiency gains relative to a VCM occur, though being largely driven by significant reductions of contributions in VCM. By apparently influencing the perception of fair burden sharing, the endowment allocation procedure crucially impacts voluntary contributions under VCM, while the rule-based mechanisms generate stable efficiency levels, even though endowment heterogeneity substantially limits the ability of rule-based mechanisms to achieve the potential efficiency gains

B-Meson Distribution Amplitudes of Geometric Twist vs. Dynamical Twist

Two- and three-particle distribution amplitudes of heavy pseudoscalar mesons of well-defined geometric twist are introduced. They are obtained from appropriately parametrized vacuum-to-meson matrix elements by applying those twist projectors which determine the enclosed light-cone operators of definite geometric twist and, in addition, observing the heavy quark constraint. Comparing these distribution amplitudes with the conventional ones of dynamical twist we derive relations between them, partially being of Wandzura-Wilczek type; also sum rules of Burkhardt-Cottingham type are derived.The derivation is performed for the (double) Mellin moments and then re-summed to the non-local distribution amplitudes. Furthermore, a parametrization of vacuum-to-meson matrix elements for non-local operators off the light-cone in terms of distribution amplitudes accompanying independent kinematical structures is derived.Comment: 18 pages, Latex 2e, no figure

Experimental validation of computerised models of clustering of platelet glycoprotein receptors that signal via tandem SH2 domain proteins

The clustering of platelet glycoprotein receptors with cytosolic YxxL and YxxM motifs, including GPVI, CLEC-2 and PEAR1, triggers activation via phosphorylation of the conserved tyrosine residues and recruitment of the tandem SH2 (Src homology 2) domain effector proteins, Syk and PI 3-kinase. We have modelled the clustering of these receptors with monovalent, divalent and tetravalent soluble ligands and with transmembrane ligands based on the law of mass action using ordinary differential equations and agent-based modelling. The models were experimentally evaluated in platelets and transfected cell lines using monovalent and multivalent ligands, including novel nanobody-based divalent and tetravalent ligands, by fluorescence correlation spectroscopy. Ligand valency, receptor number, receptor dimerisation, receptor phosphorylation and a cytosolic tandem SH2 domain protein act in synergy to drive receptor clustering. Threshold concentrations of a CLEC-2-blocking antibody and Syk inhibitor act in synergy to block platelet aggregation. This offers a strategy for countering the effect of avidity of multivalent ligands and in limiting off-target effects

Genetic regulation of plasma von Willebrand factor levels: quantitative trait loci analysis in a mouse model

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72680/1/j.1538-7836.2007.02325.x.pd

Cohesin SMC1β protects telomeres in meiocytes

Telomeres fail to attach to the nuclear envelope and lose structural integrity in cells lacking SMC1β