154 research outputs found

    Income inequality, income, and internet searches for status goods : a cross-national study of the association between inequality and well-being

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    Is there a positive association between a nation’s income inequality and concerns with status competition within that nation? Here we use Google Correlate and Google Trends to examine frequency of internet search terms and find that people in countries in which income inequality is high search relatively more frequently for positional brand names such as Prada, Louis Vuitton, or Chanel. This tendency is stronger among well-developed countries. We find no evidence that income alone is associated with searches for positional goods. We also present evidence that the concern with positional goods does not reflect non-linear effects of income on consumer spending, either across nations or (extending previous findings that people who live in unequal US States search more for positional goods) within the USA. It is concluded that income inequality is associated with greater concerns with positional goods, and that this concern is reflected in internet searching behaviour

    Geometrical properties of Potts model during the coarsening regime

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    We study the dynamic evolution of geometric structures in a poly-degenerate system represented by a qq-state Potts model with non-conserved order parameter that is quenched from its disordered into its ordered phase. The numerical results obtained with Monte Carlo simulations show a strong relation between the statistical properties of hull perimeters in the initial state and during coarsening: the statistics and morphology of the structures that are larger than the averaged ones are those of the initial state while the ones of small structures are determined by the curvature driven dynamic process. We link the hull properties to the ones of the areas they enclose. We analyze the linear von-Neumann--Mullins law, both for individual domains and on the average, concluding that its validity, for the later case, is limited to domains with number of sides around 6, while presenting stronger violations in the former case.Comment: 12 page

    Classical transverse Ising spin glass with short- range interaction beyond the mean field approximation

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    The classical transverse field Ising spin- glass model with short-range interactions is investigated beyond the mean- field approximation for a real d- dimensional lattice. We use an appropriate nontrivial modification of the Bethe- Peierls method recently formulated for the Ising spin- glass. The zero- temperature critical value of the transverse field and the linear susceptibility in the paramagnetic phase are obtained analytically as functions of dimensionality d. The phase diagram is also calculated numerically for different values of d. In the limit d -> infinity, known mean- field results are consistently reproduced.Comment: LaTex, 11 pages, 2 figure

    History Dependent Phenomena in the Transverse Ising Ferroglass: the Free Energy Landscape

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    In this paper we investigate the relationship between glassy and ferromagnetic phases in disordered Ising ferromagnets in the presence of transverse magnetic fields, Γ\Gamma. Iterative mean field simulations probe the free energy landscape and suggest the existence of a glass transition as a function of Γ\Gamma which is distinct from the Curie temperature. New experimental field-cooled and zero-field-cooled data on LiHox_xY1x_{1-x}F4_4 provide support for our theoretical picture.Comment: 4 pages RevTex; 5 figure

    Incomparability and incommensurability in choice : no common currency of value?

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    Models of decision-making typically assume the existence of some common currency of value, such as utility, happiness, or inclusive fitness. This common currency is taken to allow comparison of options and to underpin everyday choice. Here we suggest instead that there is no universal value scale, that incommensurable values pervade everyday choice, and hence that most existing models of decision-making in both economics and psychology are fundamentally limited. We propose that choice objects can be compared only with reference to specific but nonuniversal “covering values.” These covering values may reflect decision-makers’ goals, motivations, or current states. A complete model of choice must accommodate the range of possible covering values. We show that abandoning the common-currency assumption in models of judgment and decision-making necessitates rank-based and “simple heuristics” models that contrast radically with conventional utility-based approaches. We note that if there is no universal value scale, then Arrow’s impossibility theorem places severe bounds on the rationality of individual decision-making and hence that there is a deep link between the incommensurability of value, inconsistencies in human decision-making, and rank-based coding of value. More generally, incommensurability raises the question of whether it will ever be possible to develop single-quantity-maximizing models of decision-making

    Models of deliberate ignorance in individual choice

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    This chapter reviews models of deliberate ignorance and argues that models developed in both psychology and economics may be useful in understanding different aspects of deliberate ignorance. Such models must specify what quantity is increased at the expense of the potential benefits of the ignored information. A model classification is developed based on the quantity that different models assumed to be so increased. Three broad classes of relevant models are identified: (a) models that assume that utility associated with the content of beliefs may be increased by deliberate ignorance, (b) models that assume that the consistency of beliefs with each other or with a sense of identity may be increased by deliberate ignorance, and (c) models that assume that the quality of decision making may be increased by deliberate ignorance. Gaps in the literature are identified. In particular, it is suggested that insufficient attention has been given to the distinction between the effects on an agent’s utility of acquiring information (a one-off change) and possession of information (being in a steady-state of changed beliefs). Ultimately, models of deliberate ignorance will need to address the relationship between people’s (often partial and contradictory) knowledge about the world and their reasoning about that world

    Ground-State Phase Diagram of the Two-Dimensional Quantum Heisenberg Mattis Model

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    The two-dimensional S=1/2S=1/2 asymmetric Heisenberg Mattis model is investigated with the exact diagonalization of finite clusters. The N\'eel order parameter and the spin glass order parameter can be smoothly extrapolated to the thermodynamic limit in the antiferromagnetic region, as in the pure Heisenberg antiferromagnet. The critical concentration of the N\'eel phase is consistent with that of the two-dimensional Ising Mattis model, and the spin glass order parameter increases monotonously as the ferro-bond concentration increases. These facts suggest that quantum fluctuation does not play an essential role in two-dimensional non-frustrated random spin systems. KEYWORDS: quantum spin system, ground state, randomness, Mattis model, N\'eel order, spin glass orderComment: 10 pages, LaTeX, 6 compressed/uuencoded postscript figures, J. Phys. Soc. Jpn. 65 (1996) No. 2 in pres

    Replica analysis of the generalized p-spin interaction glass model

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    We investigate stability of replica symmetry breaking solutions in generalized pp-spin models. It is shown that the kind of the transition to the one-step replica symmetry breaking state depends not only on the presence or absence of the reflection symmetry of the generalized "spin"-operators U^\hat{U} but on the number of interacting operators and their individual characteristics.Comment: 14 pages, 1 figur

    First-order transitions and triple point on a random p-spin interaction model

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    The effects of competing quadrupolar- and spin-glass orderings are investigated on a spin-1 Ising model with infinite-range random pp-spin interactions. The model is studied through the replica approach and a phase diagram is obtained in the limit pp\to\infty. The phase diagram, obtained within replica-symmetry breaking, exhibits a very unusual feature in magnetic models: three first-order transition lines meeting at a commom triple point, where all phases of the model coexist.Comment: 9 pages, 2 ps figures include
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