Financial fragility in a basic agent-based model

A simple agent-based model of business units lending money to one another is sufficient to understand on what conditions avalanches of bankruptcies may arise. The model highlights the consequences of specialisation into money lending as well as the impact of preferential lending relations

Monetary economics from econophysics perspective

This is an invited article for the Discussion and Debate special issue of The European Physical Journal Special Topics on the subject "Can Economics Be a Physical Science?" The first part of the paper traces the personal path of the author from theoretical physics to economics. It briefly summarizes applications of statistical physics to monetary transactions in an ensemble of economic agents. It shows how a highly unequal probability distribution of money emerges due to irreversible increase of entropy in the system. The second part examines deep conceptual and controversial issues and fallacies in monetary economics from econophysics perspective. These issues include the nature of money, conservation (or not) of money, distinctions between money vs. wealth and money vs. debt, creation of money by the state and debt by the banks, the origins of monetary crises and capitalist profit. Presentation uses plain language understandable to laypeople and may be of interest to both specialists and general public.Comment: 23 pages, 1 figur

The dynamics of financial stability in complex networks

We address the problem of banking system resilience by applying off-equilibrium statistical physics to a system of particles, representing the economic agents, modelled according to the theoretical foundation of the current banking regulation, the so called Merton-Vasicek model. Economic agents are attracted to each other to exchange `economic energy', forming a network of trades. When the capital level of one economic agent drops below a minimum, the economic agent becomes insolvent. The insolvency of one single economic agent affects the economic energy of all its neighbours which thus become susceptible to insolvency, being able to trigger a chain of insolvencies (avalanche). We show that the distribution of avalanche sizes follows a power-law whose exponent depends on the minimum capital level. Furthermore, we present evidence that under an increase in the minimum capital level, large crashes will be avoided only if one assumes that agents will accept a drop in business levels, while keeping their trading attitudes and policies unchanged. The alternative assumption, that agents will try to restore their business levels, may lead to the unexpected consequence that large crises occur with higher probability

Three great american disinflations

In this paper, we examine three famous episodes of deliberate deflation (or disinflation) in U.S. history, including episodes following the Civil War, World War I, and the Volcker disinflation of the early 1980s. These episodes were associated with widely divergent effects on the real economy, which we attribute both to differences in the policy actions undertaken, and to the transparency and credibility of the monetary authorities. We attempt to account for the salient features of each episode within the context of a stylized DSGE model. Our model simulations indicate how a more predictable policy of gradual deflation could have helped avoid the sharp post-WWI depression. But our analysis also suggests that the strong argument for gradualism under a transparent monetary regime becomes less persuasive if the monetary authority lacks credibility; in this case, an aggressive policy stance (as under Volcker) can play a useful signalling role by making a policy shift more apparent to private agents. JEL Classification: E31, E32, E5

Behavioral Economics: Past, Present, Future

Behavioral economics increases the explanatory power of economics by providing it with more realistic psychological foundations. This book consists of representative recent articles in behavioral economics. This chapter is intended to provide an introduction to the approach and methods of behavioral economics, and to some of its major findings, applications, and promising new directions. It also seeks to fill some unavoidable gaps in the chapters’ coverage of topics

Learning and the Welfare Implications of Changing Inflation Targets

This paper computes the welfare consequences, for a representative agent, of a shift in the inflation target of monetary authorities. The welfare computations are conducted first by comparing the two steady states that the different inflation targets entail, and next by accounting for the transition from one steady-state to the next. Further, the paper allows this transition to be characterized by incomplete information, under which private agents learn about the inflation target shift using Bayesian updating. The analysis is repeated in a variety of model parameterizations, to test the robustness of the results. We find that the welfare benefits of reducing the target rate of inflation from 2% initially to 0% may at first appear to be significant. When measured by comparing steady states, these benefits are worth up to 0.5% of steady-state consumption. However, accounting for the transition towards the new, low inflation steady state significantly reduces the computed benefits, by at least one half.Inflation targeting, welfare benefits of lower inflation, new keynesian model