Relaxation in statistical many-agent economy models

We review some statistical many-agent models of economic and social systems inspired by microscopic molecular models and discuss their stochastic interpretation. We apply these models to wealth exchange in economics and study how the relaxation process depends on the parameters of the system, in particular on the saving propensities that define and diversify the agent profiles.Comment: Revised final version. 6 pages, 5 figure

Time-to-build obsolescence and the technological paradox

The paper focusses on the technological paradox. To analyze the possible temporary negative eect of an innovation, we make use of a ow representation of production. Our aim is to show that such phenomenon can be justied by a simple property of the production process: in real time costs strictly come before proceeds.Moving in the same direction of Amendola (1974), we analyze the obsolescence effect induced by a rise in the interest rate. Furthermore, we analyze the role of capital market stickiness on the timing of the technological paradox and on the distribution of the obsolescence eect among the different stages of a vertical integrated production system.Technological paradox, technology adoption, time-to-build, obsolescence.

Kinetic models of immediate exchange

We propose a novel kinetic exchange model differing from previous ones in two main aspects. First, the basic dynamics is modified in order to represent economies where immediate wealth exchanges are carried out, instead of reshufflings or uni-directional movements of wealth. Such dynamics produces wealth distributions that describe more faithfully real data at small values of wealth. Secondly, a general probabilistic trading criterion is introduced, so that two economic units can decide independently whether to trade or not depending on their profit. It is found that the type of the equilibrium wealth distribution is the same for a large class of trading criteria formulated in a symmetrical way with respect to the two interacting units. This establishes unexpected links between and provides a microscopic foundations of various kinetic exchange models in which the existence of a saving propensity is postulated. We also study the generalized heterogeneous version of the model in which units use different trading criteria and show that suitable sets of diversified parameter values with a moderate level of heterogeneity can reproduce realistic wealth distributions with a Pareto power law.Comment: 10 pages, 7 figure

Classical and quantum Brownian motion in an electromagnetic field

The dynamics of a Brownian particle in a constant magnetic field and time-dependent electric field is studied in the limit of white noise, using a Langevin approach for the classical problem and the path-integral Feynman-Vernon and Caldeira-Leggett framework for the quantum problem. We study the time evolution in configuration space of the probability distribution of an initial pure state represented by an asymmetrical Gaussian wave function and show that it can be described as the superposition of (a) the classical motion of the center of mass, (b) a rotation around the mean position, and (c) a spreading processes along the principal axes.Comment: Presented at FQMT15-Frontiers of Quantum and Mesoscopic Thermodynamics, July 27-August 1, 2015, Prague, Czech Republi

Tax compliance, income distribution and social norms

This paper studies the effect of income inequality on tax evasion. To discuss the topic, we present a simple model, based on Benabou and Tirole [6], that incorporates incentives for tax compliance such as punishment and fines, intrinsic motivation and social norms. Since we consider a regressive system of incentives to comply, income inequality increases the value of tax evasion although overall propensity to comply is unaffected. In this framework, we consider the hypothesis that social norms are group specific as in the case of social segregation or status related networks. We show that all the negative effects of inequalities are amplified: the difference between the tax compliance of the income groups and the value of tax evasion increase