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Martin Shubik Publications

Publish Date
Abstract

Closed exchange and production-and-exchange economies may have multiple equilibria, a fact that is usually ignored in macroeconomic models. Our basic argument is that default and bankruptcy laws are required to prevent strategic default, and these laws can also serve to provide the conditions for uniqueness. In this paper, we report experimental evidence on the effectiveness of this approach to resolving multiplicity: a society can assign default penalties on fiat money so that the economy selects one of the equilibria. Our data show that the choice of default penalty takes the economy close to the chosen equilibrium. The theory and evidence together reinforce the idea that accounting, bankruptcy and possibly other aspects of social mechanisms play an important role in resolving the otherwise mathematically intractable challenges associated with multiplicity of equilibria in closed economies.

Abstract

A link between a no-side-payment (NSP) market game and a side-payment (SP) market game can be established by introducing a sufficient amount of an ideal utility-money of constant marginal utility to all agents. At some point when there is “enough money” in the system, if it is “well distributed” the new game will be a SP game. This game can also be related to a pure NSP game where a set of default parameters have been introduced. These parameters play a role similar to the parameters specifying the interpersonal comparisons in the side-payment game. We study this game for the properties of the delta-core and consider both the conditions for the uniqueness of competitive equilibria and a new approach to the second welfare theorem. A discussion of the relationship between market games and strategic market games is also noted.

Abstract

The enlargement of the general-equilibrium structure to allow default subject to penalties results in a construction of a simple mechanism for selecting a unique competitive equilibrium. We consider economies for which a common credit money can be applied to uniquely select any competitive equilibrium with suitable default penalties. We identify two classes of such economies. One consists of economies with utility functions being homogeneous of degree 1; the other consists of economies with the number of consumers equal to the number of commodities and traders having quasi-linear utility functions with respect to different commodities.

Abstract

We present a model in which an outside bank and a default penalty support the value of fiat money, and experimental evidence that the theoretical predictions about the behavior of such economies, based on the Fisher-condition, work reasonably well in a laboratory setting. The import of this finding for the theory of money is to show that the presence of a societal bank and default laws provide sufficient structure to support the use of fiat money and use of the bank rate to influence inflation or deflation, although other institutions could provide alternatives.

Abstract

Why people accept intrinsically worthless fiat money in exchange for real goods and services has been a longstanding question. There are many competing sufficient explanations that may confound each other in practice but can be individually tested in isolation experimentally. In this paper we examine a sufficient explanation of the value of fiat money through the existence of a debt instrument which allows consumption to be moved earlier in time. We present experimental evidence that the theoretical predictions about the behavior of such economies work reasonably well in a laboratory setting. The import of this finding for the theory of money is to show that the presence of a societal bank and default laws provide sufficient structure to support the use of fiat money, although many other institutions such as taxation provide alternatives.

Abstract

We present a model in which an outside bank and a default penalty support the value of fiat money, and experimental evidence that the theoretical predictions about the behavior of such economies, based on the Fisher-condition, work reasonably well in a laboratory setting. The import of this finding for the theory of money is to show that the presence of a societal bank and default laws provide sufficient structure to support the use of fiat money and use of the bank rate to influence inflation or deflation, although other institutions could provide alternatives.

Abstract

A discussion is given of the problems involved in the formal modeling of the innovation process. The link between innovation and finance is stressed. The nature of how the circular flow of funds is broken and the role of finance in evaluation and control is discussed.

Abstract

We define and examine the performance of three minimal strategic market games (sell-all, buy-sell, and double auction) in laboratory relative to the predictions of theory. Unlike open or partial equilibrium settings of most other experiments, these closed exchange economies have limited amounts of cash to facilitate transactions and include feedback. General equilibrium theory, since it abstracts away from market mechanisms and has no role for money or credit, makes no predictions about how the paths of convergence to the competitive equilibrium may differ across alternative mechanisms. Introduction of markets and money as carriers of process creates the possibility of motion. The laboratory data reveal different paths, and different levels of allocative efficiency in the three settings. The results suggest that abstracting away from all institutional details does not help understand dynamic aspects of market behavior. For example, the oligopoly effect of feedback from buying an endowed good is missed. Inclusion of mechanism differences into theory may enhance our understanding of important aspects of markets and money and help link conventional equilibrium analysis with dynamics.

Abstract

Is personal currency issued by participants sufficient to operate an economy efficiently, with no outside or government money? Sahi and Yao (1989) and Sorin (1996) constructed a strategic market game to prove that this is possible. We conduct an experimental game in which each agent issues her personal IOUs, and a costless efficient clearinghouse adjusts the exchange rates among them so the markets always clear. The results suggest that if the information system and clearing are so good as to preclude moral hazard, any form of information asymmetry, and need for trust, the economy operates efficiently at any price level without government money. These conditions cannot reasonably be expected to hold in natural settings. In a second set of treatments when agents have the option of not delivering on their promises, a high enough penalty for non-delivery is necessary to ensure an efficient market; a lower penalty leads to inefficient, even collapsing, markets due to moral hazard.

Abstract

We define and examine three minimal market games (sell-all, buy-sell, and double auction) in the laboratory relative to the predictions of theory. These closed exchange economies have some cash to facilitate transactions, and include feedback. The experiment reveals that (1) the competitive general equilibrium (CGE) and non-cooperative (NCE) models are reasonable anchors to locate most but not all the observed outcomes of the three market mechanisms; (2) outcomes tend to get closer to CGE predictions as the number of players increases; (3) prices and allocations in double auctions deviate persistently from CGE predictions; (4) the outcome paths across the three market mechanisms differ significantly and persistently; (5) importance of market structures for outcomes is reinforced by algorithmic trader simulations; and (6) none of the three markets dominates the others across six measures of performance. Inclusion of some mechanism differences into theory may enhance our understanding of important aspects of markets.

Games and Economic Behavior
Abstract

We define and examine the performance of three minimal strategic market games (sell-all, buy-sell, and double auction) in laboratory relative to the predictions of theory. Unlike open or partial equilibrium settings of most other experiments, these closed exchange economies have limited amounts of cash to facilitate transactions and include feedback. General equilibrium theory, since it abstracts away from market mechanisms and has no role for money or credit, makes no predictions about how the paths of convergence to the competitive equilibrium may differ across alternative mechanisms. Introduction of markets and money as carriers of process creates the possibility of motion. The laboratory data reveal different paths, and different levels of allocative efficiency in the three settings. The results suggest that abstracting away from all institutional details does not help understand dynamic aspects of market behavior. For example, the oligopoly effect of feedback from buying an endowed good is missed. Inclusion of mechanism differences into theory may enhance our understanding of important aspects of markets and money and help link conventional equilibrium analysis with dynamics.

Keywords: Strategic market games, Laboratory experiments, Minimally intelligent agents, Adaptive learning agents, General equilibrium

JEL Classification: C92, D43, D51, D58, L13

Annals of Finance
Abstract

Is personal currency issued by participants sufficient to operate an economy efficiently, with no outside or government money? Sahi and Yao (1989) and Sorin (1996) constructed a strategic market game to prove that this is possible. We conduct an experimental game in which each agent issues her personal IOUs, and a costless efficient clearinghouse adjusts the exchange rates among them so the markets always clear. The results suggest that if the information system and clearing are so good as to preclude moral hazard, any form of information asymmetry, and need for trust, the economy operates efficiently at any price level without government money. These conditions cannot reasonably be expected to hold in natural settings. In a second set of treatments when agents have the option of not delivering on their promises, a high enough penalty for non-delivery is necessary to ensure an efficient market; a lower penalty leads to inefficient, even collapsing, markets due to moral hazard.

Keywords: Strategic market games, Government and individual money, Efficiency, Experimental gaming

JEL Classification: C73, C91