THERMAL CONDUCTIVITY FOR A NOISY DISORDERED HARMONIC CHAIN

We consider a $d$-dimensional disordered harmonic chain (DHC) perturbed by an energy conservative noise. We obtain uniform in the volume upper and lower bounds for the thermal conductivity defined through the Green-Kubo formula. These bounds indicate a positive finite conductivity. We prove also that the infinite volume homogenized Green-Kubo formula converges

Heat Conduction and Entropy Production in Anharmonic Crystals with Self-Consistent Stochastic Reservoirs

We investigate a class of anharmonic crystals in $d$ dimensions, $d\ge 1$, coupled to both external and internal heat baths of the Ornstein-Uhlenbeck type. The external heat baths, applied at the boundaries in the 1-direction, are at specified, unequal, temperatures \tlb and \trb. The temperatures of the internal baths are determined in a self-consistent way by the requirement that there be no net energy exchange with the system in the non-equilibrium stationary state (NESS). We prove the existence of such a stationary self-consistent profile of temperatures for a finite system and show it minimizes the entropy production to leading order in (\tlb -\trb). In the NESS the heat conductivity $\kappa$ is defined as the heat flux per unit area divided by the length of the system and (\tlb -\trb). In the limit when the temperatures of the external reservoirs goes to the same temperature $T$, $\kappa(T)$ is given by the Green-Kubo formula, evaluated in an equilibrium system coupled to reservoirs all having the temperature $T$. This $\kappa(T)$ remains bounded as the size of the system goes to infinity. We also show that the corresponding infinite system Green-Kubo formula yields a finite result. Stronger results are obtained under the assumption that the self-consistent profile remains bounded.Comment: to appear in J. Stat. Phy

On the Role of Pre-Determined Rules for HRM Policies

Using simple game-theoretical models, this paper studies the role of pre-determined rules for HRM policies. We consider a model in which HRM decisions affect employees' self-images and thereby their motivation. We show that in the absence of written rules, managers are too reluctant (1) to differentiate between employees on the basis of their abilities, and (2) to terminate employment of employees on probation. Generally, organizations benefit from committing to strict rules for various HRM practices

Entanglement between Demand and Supply in Markets with Bandwagon Goods

Whenever customers' choices (e.g. to buy or not a given good) depend on others choices (cases coined 'positive externalities' or 'bandwagon effect' in the economic literature), the demand may be multiply valued: for a same posted price, there is either a small number of buyers, or a large one -- in which case one says that the customers coordinate. This leads to a dilemma for the seller: should he sell at a high price, targeting a small number of buyers, or at low price targeting a large number of buyers? In this paper we show that the interaction between demand and supply is even more complex than expected, leading to what we call the curse of coordination: the pricing strategy for the seller which aimed at maximizing his profit corresponds to posting a price which, not only assumes that the customers will coordinate, but also lies very near the critical price value at which such high demand no more exists. This is obtained by the detailed mathematical analysis of a particular model formally related to the Random Field Ising Model and to a model introduced in social sciences by T C Schelling in the 70's.Comment: Updated version, accepted for publication, Journal of Statistical Physics, online Dec 201

How many educated workers for your economy? European targets, optimal public spending, and labor market impact

This paper studies optimal taxation schemes for education in a search- matching model where the labor market is divided between a high-skill and a low-skill sector. Two public policy targets - maximizing the total employment level and optimizing the social surplus - are studied according to three different public taxation strategies. We calibrate our model using evidence from thirteen European countries, and compare our results with the target from the Europe 2020 Agenda for achievement in higher education. We show that, with current labor market char- acteristics, the target set by governments seems compatible with the social surplus maximization objective for some countries, while being too high for other countries. For all countries, maximizing employment would imply higher educational spending than that required for the social surplus to reach its maximum.info:eu-repo/semantics/publishedVersio

Can Tailored Communications Motivate Volunteers? A Field Experiment

Over 25% of the US population volunteers. Clary et al. (1998) devised a survey that identifies a volunteer’s primary motive for volunteering. We investigate the effect of tailoring the communications that volunteers receive from their organizations (e.g., printed newsletters, update emails) to each volunteer’s stated motive for volunteering affects volunteer performance. We find that in general, such tailoring has no effect, but that for volunteers who are motivated primarily by the pursuit of career-related benefits, such tailoring can have a substantial, positive effect on hours volunteered. We also find that the (in)effectiveness of this tailoring does not depend upon the volunteers’ knowledge of the tailoring. The tailoring of communications does not involve the explicit manipulation of material incentives. This renders it particularly attractive given the emergence of evidence on how extrinsic incentives can crowd out intrinsic incentives, especially in the domain of charitable contributions