Interaction Of Heterogeneous Agents Research Articles

General Equilibrium Model with Tax Audit and Endogenous Choice between Labor Market and Self-Employment

A general equilibrium model, which describes the interaction of heterogeneous agents who choose between the labor market and self-employment and the state, which plays the role of an inspection body (auditor) in a model that controls the fact of tax evasion, is considered. It is shown that in the case of information asymmetry, the tax rate that maximizes the amount of tax revenues increases. Under information asymmetry, the Laffer curve approaches its analog with symmetric information if the penalties or the budgets of the tax office are high. Despite the fact that in equilibrium the amount of penalties paid is zero, they have a significant effect on the amount of tax revenues. As an effective deterrent to tax violators, they are increasing the amount of tax collections at a slower pace.

20 years of WEHIA: A journey in search of a safer road

The central theme of a series of workshops since 1996 entitled Workshops on Economics with Heterogeneous Interactive Agents (WEHIA), has been that of examining how aggregate economic properties arise from the actions and interactions of heterogeneous individuals. The workshop aimed to bring together scholars of different disciplines working on interaction of heterogeneous agents, particles or various forms of animal life. WEHIA aimed to be a locus for these scholars to communicate and exchange results and experiences. After identifying a pars destruens and a pars adstruens of the workshop, we identify some possible developments of the themes of WEHIA.

Financial market equilibria with heterogeneous agents: CAPM and market segmentation

We consider a single-period financial market model with normally distributed returns and heterogeneous agents. Specifically, some investors are classical expected utility maximizers whereas some others follow cumulative prospect theory. Using well-known functional forms for the preferences, we analytically prove that a Security Market Line Theorem holds. This implies that capital asset pricing model is a necessary (though not sufficient) requirement in equilibria with positive prices. We prove that equilibria may not exist and we give explicit sufficient conditions for an equilibrium to exist. To circumvent the complexity arising from the interaction of heterogeneous agents, we propose a segmented-market equilibrium model where segmentation is endogenously determined.

Macroeconomic Stabilization Policies in Intrinsically Unstable Macroeconomies

Many monetary and fiscal policy measures have aimed at mitigating the effects of the financial market meltdown that started in the U. S. subprime sector in 2008 and has subsequently spread world wide as a great recession. Slowly some recovery appears to be on the horizon, yet it is worthwhile exploring the fragility and potentially destabilizing feedbacks of advanced macroeconomies in the context of a framework that builds on the ideas of Keynes and Tobin. This framework stresses the fragilities and destabilizing feedback mechanisms that are potential features of all major markets-those for goods, labor, and financial assets. We use a Tobin macroeconomic portfolio approach and the interaction of heterogeneous agents on the financial market to characterize the potential for financial market instability. Though the study of the latter has been undertaken in many partial models, we focus here on the interconnectedness of all three markets. Furthermore, we study what potential labor market, fiscal and monetary policies can have in stabilizing unstable macroeconomies. In order to study this problem we introduce, besides money, long term bonds and equity into the asset market. We in particular propose a countercyclical monetary policy that sells assets in the boom and purchases them in recessions. Modern stability analysis is brought to bear to demonstrate the stabilizing effects of the suggested policies. The policies suggested here could help the Fed in its search for an appropriate exit strategy after its massive intervention in the financial market.

Stabilizing an unstable economy: Fiscal and monetary policy, stocks, and the term structure of interest rates

Monetary and fiscal policy measures have been applied in order to avert the financial market collapse and counteract the global recession. In this paper we present an integrated macromodel which in particular focuses on the financial markets. We use a Tobin-like macroeconomic portfolio approach, and the interaction of heterogeneous agents on the financial market to characterize the potential for financial market instability. We show that specific but unorthodox fiscal and monetary policies have to be used to stabilize such unstable macroeconomies.

Stabilizing an Unstable Economy: On the Choice of Proper Policy Measures

Abstract In the last months, the world’s economies were confronted with the largest economic recession since the Great Depression. The occurrence of a worldwide financial market meltdown as a consequence originally stemming from of the crisis in the US subprime housing sector was only prevented by extraordinary monetary and fiscal policy measures implemented at the international level. Although the world economy seems now to be slowing recovering, it is worthwhile exploring the fragility and potentially destabilizing feedbacks of advanced macroeconomies in the context of Keynesian macro models. Fragilities and destabilizing feedback mechanisms are known to be potential features of all markets—the product markets, the labor market, and the financial markets. In this paper we focus in particular on the financial market. We use a Tobin-like macroeconomic portfolio approach, and the interaction of heterogeneous agents on the financial market to characterize the potential instability of the financial markets. Though the study of the latter has been undertaken in many partial models, we focus here on the interconnectedness of all three markets. Furthermore, we also study how labor market, fiscal and monetary policies can stabilize unstable macroeconomies. Besides other stabilizing policies we in particular propose a countercyclical monetary policy that sells assets in the boom and purchases assets in recessions. Modern stability analysis is brought to bear to demonstrate the stabilizing effects of those suggested policies.

BUILDING AN ARTIFICIAL STOCK MARKET POPULATED BY REINFORCEMENT‐LEARNING AGENTS

In this paper we propose an artificial stock market model based on interaction of heterogeneous agents whose forward-looking behaviour is driven by the reinforcement-learning algorithm combined with some evolutionary selection mechanism. We use the model for the analysis of market self-regulation abilities, market efficiency and determinants of emergent properties of the financial market. Distinctive and novel features of the model include strong emphasis on the economic content of individual decision-making, application of the Q-learning algorithm for driving individual behaviour, and rich market setup. Along with that a parallel version of the model is presented, which is mainly based on research of current changes in the market, as well as on search of newly emerged consistent patterns, and which has been repeatedly used for optimal decisions’ search experiments in various capital markets.

Stabilizing an Unstable Economy: On the Choice of Proper Policy Measures

In the last months, the world's economies were confronted with the largest economic recession since the Great Depression. The occurrence of a worldwide financial market meltdown as a consequence originally stemming from of the crisis in the US subprime housing sector was only prevented by extraordinary monetary and fiscal policy measures implemented at the international level. Although the world economy seems now to be slowing recovering, it is worthwhile exploring the fragility and potentially destabilizing feedbacks of advanced macroeconomies in the context of Keynesian macro models. Fragilities and destabilizing feedback mechanisms are known to be potential features of all markets-the product markets, the labor market, and the financial markets. In this paper we focus in particular on the financial market. We use a Tobin-like macroeconomic portfolio approach, and the interaction of heterogeneous agents on the financial market to characterize the potential instability of the financial markets. Though the study of the latter has been undertaken in many partial models, we focus here on the interconnectedness of all three markets. Furthermore, we also study how labor market, fiscal and monetary policies can stabilize unstable macroeconomies. Besides other stabilizing policies we in particular propose a countercyclical monetary policy that sells assets in the boom and purchases assets in recessions. Modern stability analysis is brought to bear to demonstrate the stabilizing effects of those suggested policies. --