18,140 research outputs found

    DEMAND FOR AGRICULTURAL ECONOMIC INFORMATION

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    Using data gathered in two surveys we analyze the movement of information in agriculture. The relative importance of varying classes of information providers are assessed by classes of users. A network based framework expands models of human capital and bounded rationality to assess the calculus of choice of information.information, bounded rationality, Institutional and Behavioral Economics,

    Loss Aversion and Reference Points in Contracts

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    Loss aversion has become the dominant alternative to expected utility theory for modeling choice under uncertainty. The setting of the base payment in contracts provides an interesting application of referenced based decision theory. The impact of loss aversion on contract structure depends critically on whether reservation opportunities (outside options) are evaluated with respect to the reference point implied in the contract. We show that when reservation opportunities are independent of the reference point, reward contracts are optimal. However, when reservation opportunities are evaluated against the reference point, then penalty contracts are more efficient.Risk and Uncertainty, L14, D81, D21, D82,

    Weak plaquette valence bond order in the S=1/2S=1/2 honeycomb J1J2J_1-J_2 Heisenberg model

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    Using the density matrix renormalization group, we investigate the S=1/2S=1/2 Heisenberg model on the honeycomb lattice with first- (J1J_1) and second-neighbor (J2J_2) interactions. We are able to study long open cylinders with widths up to 12 lattice spacings. For J2/J1J_2/J_1 near 0.3, we find an apparently paramagnetic phase, bordered by an antiferromagnetic phase for J20.26J_2\lesssim 0.26 and by a valence bond crystal for J20.36J_2\gtrsim 0.36. The longest correlation length that we find in this intermediate phase is for plaquette valence bond (PVB) order. This correlation length grows strongly with cylinder circumference, indicating either quantum criticality or weak PVB order.Comment: 9 pages, 15 figures, minor changes are made for publication in Phys. Rev. Let

    Unexpected z-Direction Ising Antiferromagnetic Order in a frustrated Spin-1/2 J1J2J_1-J_2 XY Model on the Honeycomb Lattice

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    Using the density matrix renormalization group (DMRG) on wide cylinders, we study the phase diagram of the spin-1/2 XY model on the honeycomb lattice, with first-neighbor (J1=1J_1 = 1) and frustrating second-neighbor (J2>0J_2>0) interactions. For the intermediate frustration regime 0.22J20.360.22\lesssim J_2\lesssim0.36, we find a surprising antiferromagnetic Ising phase, with ordered moments pointing along the z axis, despite the absence of any S_z_z interactions in the Hamiltonian. Surrounding this phase as a function of J2J_2 are antiferromagnetic phases with the moments pointing in the xyx-y plane for small J2J_2 and a close competition between an xyx-y plane magnetic collinear phase and a dimer phase for large values of J2J_2. We do not find any spin liquid phases in this model.Comment: 5 pages, 5 figures, minor changes made for publication on PR
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