A dynamic model of a monetary production economy under the disequilibrium economics approach

This paper presents a model of a monetary production economy with non-Walrasian good, labor and money markets. In the non-Walrasian approach, transactions occur at non clearing prices and agents's demand and supply are affected by quantity constraints in the opposite side of the market. The model is characterized by a representative firm, which maximize profits subject to a production technology, a representative consumer, which maximize utility subject to a budget constraint, and by a central bank which provide liquidity. The consumer provides the labor force and owns all the equities of the firm. The main result of the model is the existence of non-Warlasian equilibria which are suboptimal with respect to Warlasian ones. Furthermore, non-Warlasian equilibria are characterized by money non-neutrality and proper monetary policies are found to be able to bring the system near to the Walrasian pointdisequilibrium economics; economic dynamics, monetary policy

Waiting-times and returns in high-frequency financial data: an empirical study

In financial markets, not only prices and returns can be considered as random variables, but also the waiting time between two transactions varies randomly. In the following, we analyse the statistical properties of General Electric stock prices, traded at NYSE, in October 1999. These properties are critically revised in the framework of theoretical predictions based on a continuous-time random walk model.Duration; Continuous-time random walk; Fractional calculus; Statistical finance.

Correlations in the Bond–Future Market

We analyze the time series of overnight returns for the bund and btp futures exchanged at liffe (London). The overnight returns of both assets are mapped onto a one–dimensional symbolic–dynamics random walk: The “bond walk”. During the considered period (October 1991—January 1994) the bund–future market opened earlier than the btp–future one. The cross correlations between the two bond walks, as well as estimates of the conditional probability, show that they are not independent; however each walk can be modeled by means of a trinomial probability distribution. Monte Carlo simulations confirm that it is necessary to take into account the bivariate dependence in order to properly reproduce the statistical properties of the real–world data. Various investment strategies have been devised to exploit the “prior” information obtained by the aforementioned analysis.Random walk, complex systems, financial markets

Revisiting the derivation of the fractional diffusion equation

The fractional diffusion equation is derived from the master equation of continuous-time random walks (CTRWs) via a straightforward application of the Gnedenko-Kolmogorov limit theorem. The Cauchy problem for the fractional diffusion equation is solved in various important and general cases. The meaning of the proper diffusion limit for CTRWs is discussed.Comment: Paper presented at the International Workshop on Scaling and Disordered Systems, Paris, France, 13-14 April 200

Macroprudential policies in an agent-based artificial economy

Basel III is a recently-agreed regulatory standard for bank capital adequacy with focus on the macroprudential dimension of banking regulation, i.e., the system-wide implications of banks' lending and risk. An important Basel III provision is to reduce procyclicality of present banking regulation and promote countercyclical capital buffers for banks. The Eurace agent-based macroeconomic model and simulator has been recently showed to be able to reproduce a credit-fueled boom-bust dynamics where excessive bank leverages, while benefitting in the short term, have destabilizing effects in the medium-long. In this paper. we employ the Eurace model to test regulatory policies providing time varying capital requirements for banks, based on mechanisms that enforce banks to build up or release capital buffers, according to the overall conditions of the economy. As conditioning variables for these dynamic policies, both the unemployment rate and the aggregate credit growth have been considered. Results show that the dynamic regulation of capital requirements is generally more successful than fixed tight capital requirements in stabilizing the economy and improving the macroeconomic performance.Basel III, macroprudential regulation, agent-based models and simulation

The impact of banks’ capital adequacy regulation on the economic system: an agent-based approach

Since the start of the financial crisis in 2007, the debate on the proper level leverage of financial institutions has been flourishing. The paper addresses such crucial issue within the Eurace arti?cial economy, by considering the effects that different choices of capital adequacy ratios for banks have on main economic indicators. The study also gives us the opportunity to examine the outcomes of the Eurace model so to discuss the nature of endogenous money, giving a contribution to a debate that has grown stronger over the last two decades. A set of 40 years long simulations have been performed and examined in the short (first 5 years), medium (the following 15 years) and long (the last 20 years) run. Results point out a non-trivial dependence of real economic variables such as the Gross Domestic Product (GDP), the unemployment rate and the aggregate capital stock on banks’ capital adequacy ratios; this dependence is in place due to the credit channel and varies significantly according to the chosen evaluation horizon. In general, while boosting the economy in the short run, regulations allowing for a high leverage of the banking system tend to be depressing in the medium and long run. Results also point out that the stock of money is driven by the demand for loans, therefore supporting the theory of endogenous nature of credit money.Agent-based models, banking regulation

On the distributional properties of size, profit and growth of Icelandic firms

In this paper, we analyze the distributional properties of the balance sheets of Icelandic firms by performing an empirical analysis of total assets, profit rates and growth rates using a data set of 2818 Icelandic firms during the period 2000-2009. We find that the firms size measure, i.e. total assets, have the same heavy tail characteristics as various studies have shown, e.g. for U.S. and Italian firms. The heavy tail nature of the total assets distribution seems to be robust w.r.t. a boom-bust cycle of the economy as well as special characteristics of Icelandic firms, e.g. their relatively small size and private ownership. Another important finding is that the profit rates, or return on assets, of Icelandic firms follow a Laplace like distribution similar to U.S. firms. Additionally, we identified deviations from the distributional regularities, namely the power law behavior of firms' size and Laplacian distributions of growth and profit rates, during the booming period of the economy 2005-2007.Firm size, Profit rates, Growth rates, Power law, Laplace distribution, Icelandic Firms