On the interpretation of the WTP/WTA gap as imprecise utility: an axiomatic analysis

The willingness-to-pay (WTP) and willingness-to-accept (WTA) disparity reported in a rich empirical literature suggests that people have only an imprecise idea of how valuable a good is to them. In this note, we provide axioms that formally relate this imprecision in the evaluation of a good to the imprecision in the utility function, in the sense that x is strictly preferred to y iff the WTP for x is larger than the WTA for y. The preference relation is therefore an interval order (Fishburn (1970)) with ``interval utility' equal to the WTP/WTA interval itself. Applications to preference for liquidity and the strength of the status quo bias are given.WTA/WTP gap, interval orders, imprecise utility, reference-dependent preferences, status quo bias

Random matrix ensembles associated with Lax matrices

A method to generate new classes of random matrix ensembles is proposed. Random matrices from these ensembles are Lax matrices of classically integrable systems with a certain distribution of momenta and coordinates. The existence of an integrable structure permits to calculate the joint distribution of eigenvalues for these matrices analytically. Spectral statistics of these ensembles are quite unusual and in many cases give rigorously new examples of intermediate statistics

Perturbation approach to multifractal dimensions for certain critical random matrix ensembles

Fractal dimensions of eigenfunctions for various critical random matrix ensembles are investigated in perturbation series in the regimes of strong and weak multifractality. In both regimes we obtain expressions similar to those of the critical banded random matrix ensemble extensively discussed in the literature. For certain ensembles, the leading-order term for weak multifractality can be calculated within standard perturbation theory. For other models such a direct approach requires modifications which are briefly discussed. Our analytical formulas are in good agreement with numerical calculations.Comment: 28 pages, 7 figure

Voltage-controlled tunneling anisotropic magneto-resistance of a ferromagnetic p++p^{++}-(Ga,Mn)As/n+n^{+}-GaAs Zener-Esaki diode

The large tunneling anisotropic magneto-resistance of a single $p^{++}$-(Ga,Mn)As/$n^{+}$-GaAs Zener-Esaki diode is evidenced in a perpendicular magnetic field over a large temperature and voltage range. Under an applied bias, the tunnel junction transparency is modified, allowing to continuously tune anisotropic transport properties between the tunneling and the ohmic regimes. Furthermore, an asymmetric bias-dependence of the anisotropic tunneling magneto-resistance is also observed: a reverse bias highlights the full (Ga,Mn)As valence band states contribution, whereas a forward bias only probes part of the density of states and reveals opposite contributions from two subbands.Comment: 11 pages, 3 figure

Coordinates, modes and maps for the density functional

Special bases of orthogonal polynomials are defined, that are suited to expansions of density and potential perturbations under strict particle number conservation. Particle-hole expansions of the density response to an arbitrary perturbation by an external field can be inverted to generate a mapping between density and potential. Information is obtained for derivatives of the Hohenberg-Kohn functional in density space. A truncation of such an information in subspaces spanned by a few modes is possible. Numerical examples illustrate these algorithms.Comment: 15 pages, 9 figure

TEMPORAL PAYMENT ISSUES IN CONTINGENT VALUATION ANALYSIS

We analyze agent response to disparate payment schedules for protection of critical habitat units for the Seller sea lion in Alaska. The model allows for identification of implicit and explicit discount rates using information from a system of maximum likelihood equations. Testing is done using data for one, five, and fifteen year payment treatments.Research Methods/ Statistical Methods,

L'expansion coloniale de la fourmi d'Argentine

La fourmi Linepithema humile fait preuve d'une exceptionnelle aptitude à coloniser de très larges territoires. Cette expansion est favorisée par une organisation sociale bien différente de celle qu'elle adopte dans son pays d'origine. Quelle est la clé de ce changement

Quantum computing of delocalization in small-world networks

We study a quantum small-world network with disorder and show that the system exhibits a delocalization transition. A quantum algorithm is built up which simulates the evolution operator of the model in a polynomial number of gates for exponential number of vertices in the network. The total computational gain is shown to depend on the parameters of the network and a larger than quadratic speed-up can be reached. We also investigate the robustness of the algorithm in presence of imperfections.Comment: 4 pages, 5 figures, research done at http://www.quantware.ups-tlse.fr

Simple Computational Methods for Measuring the Difference of Empirical Distributions: Application to Internal and External Scope Tests in Contingent Valuation

This paper develops a statistically unbiased and simple method for measuring the difference of independent empirical distributions estimated by bootstrapping or other simulation approaches. This complete combinatorial method is compared with other unbiased and biased methods that have been suggested in the literature, first in Monte Carlo simulations and then in a field test of external and internal scope testing in contingent valuation. Tradeoffs between methods are discussed. When the empirical distributions are not independent a straightforward difference test is suggested.Research Methods/ Statistical Methods,