Can Higher Bonuses Lead to Less Effort? Incentive Reversal in Teams

Conventional wisdom suggests that an increase in monetary incentives should induce agents to exert higher effort. In this paper, however, we demonstrate that this may not hold in team settings. In the context of sequential team production with positive externalities between agents, incentive reversal might occur: an increase in monetary incentives (either because rewards increase or effort costs decrease) may lead agents to exert lower effort in the completion of a joint task – even if agents are fully rational, self-centered money maximizers. Herein we discuss this seemingly paradoxical phenomenon and report on two experiments that provide supportive evidence.incentives, incentive reversal, team production, externalities, laboratory experiments, personnel economics

Unification of parton and coupled-wire approaches to quantum magnetism in two dimensions

The fractionalization of microscopic degrees of freedom is a remarkable manifestation of strong interactions in quantum many-body systems. Analytical studies of this phenomenon are primarily based on two distinct frameworks: field theories of partons and emergent gauge fields, or coupled arrays of one-dimensional quantum wires. We unify these approaches for two-dimensional spin systems. Via exact manipulations, we demonstrate how parton gauge theories arise in microscopic wire arrays and explicitly relate spin operators to emergent quasiparticles and gauge-field monopoles. This correspondence allows us to compute physical correlation functions within both formulations and leads to a straightforward algorithm for constructing parent Hamiltonians for a wide range of exotic phases. We exemplify this technique for several chiral and non-chiral quantum spin liquids.Comment: 32 pages, 11 figure

Spin-charge separation in two dimensions: spinon-chargon gauge theories from duality

Strong interactions between electrons in two dimensions can realize phases where their spins and charges separate. We capture this phenomenon within a dual formulation. Focusing on square lattices, we analyze the long-wavelength structure of vortices when the microscopic particles -- electrons or spinful bosons -- are near half-filling. These conditions lead to a compact gauge theory of spinons and chargons, which arise as the fundamental topological defects of the low-energy vortices. The gauge theory formulation is particularly suitable for studying numerous exotic phases and transitions. We support the general analysis by an exact implementation of the duality of a coupled-wire array. Finally, we demonstrate how the latter can be exploited to construct parent Hamiltonians for fractional phases and their transitions

Integral constraints on the monodromy group of the hyperkahler resolution of a symmetric product of a K3 surface

Let M be a 2n-dimensional Kahler manifold deformation equivalent to the Hilbert scheme of length n subschemes of a K3 surface S. Let Mon be the group of automorphisms of the cohomology ring of M, which are induced by monodromy operators. The second integral cohomology of M is endowed with the Beauville-Bogomolov bilinear form. We prove that the restriction homomorphism from Mon to the isometry group O[H^2(M)] is injective, for infinitely many n, and its kernel has order at most 2, in the remaining cases. For all n, the image of Mon in O[H^2(M)] is the subgroup generated by reflections with respect to +2 and -2 classes. As a consequence, we get counter examples to a version of the weight 2 Torelli question, when n-1 is not a prime power.Comment: Version 3: Latex, 54 pages. Expository change

Can higher bonuses lead to less effort? Incentive reversal in teams

Conventional wisdom suggests that an increase in monetary incentives should induce agents to exert higher effort. In this paper, however, we demonstrate that this may not hold in team settings. In the context of sequential team production with positive externalities between agents, incentive reversal might occur: an increase in monetary incentives (either because rewards increase or effort costs decrease) may lead agents to exert lower effort in the completion of a joint task - even if agents are fully rational, self-centered money maximizers. Herein we discuss this seemingly paradoxical phenomenon and report on two experiments that provide supportive evidence