Closed exchange and production-and-exchange economies may have multiple equilibria, a fact that i... more 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: society can assign default penalties on fiat money so the economy selects one of the equilibria. Our data show that the choice of default penalty takes the economy to the neighborhood of 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. Additionally we discuss the meaning and experimental implications of default penalties that support an active bankruptcy-modified competitive equilibrium. JEL: C73, C92, D51, E42, G21, G33
We compare general equilibrium economies in which building and maintenance of a depreciating publ... more We compare general equilibrium economies in which building and maintenance of a depreciating public facility is financed either by anonymous voluntary contributions or by taxing agents on their income from private production. Agents start with an endowment of private goods and money, while the government starts with an endowment of public good and money. All private goods produced are tendered for sale in exchange for money in a sell-all market mechanism. Agents' proceeds from sale are taxed, and they individually allocate their private goods between current consumption and investment in production for the following period. The optimal levels of supply of the public good, and tax rate to sustain it over time, are defined and calculated for infinite and finite horizons. These equilibrium theoretical predications are compared to the outcomes of laboratory economies when (1) the starting public facility is either at or below the optimal level; and (2) the tax rate is either exogenously set at the optimal level, or at the median of rates proposed by individual agents. We find that the experimental economies sustain public goods at about 70-90 percent of the infinite horizon but considerably more than the finite horizon optimum. Payoffs (efficiency) is at 90 percent of the infinite horizon equilibrium level even when the rate of taxation is determined by voting. Starting conditions play only a minor role for outcomes of the economies, as efficiency and the stock of public good adjusts to about the same level irrespective of the starting level. These results contrast with rapid decline in provision of public goods under anonymous voluntary contributions, and point to the possibility that the social institution of government enforced taxation may have evolved to address the problem of under-production of public goods through anonymous voluntary contributions.
Is personal credit issued by participants sufficient to operate an economy efficiently, with no o... more Is personal credit issued by participants sufficient to operate an economy efficiently, with no outside or government money? Sorin (1995) constructed a strategic market game to prove that this is possible. We conduct an experimental game in which each agent issues her own 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, or need for trust, the economy operates efficiently at any price level without government money. Conversely, perhaps explanations for prevalence of government money should be sought in either the above mentioned frictions or our unwillingness to experiment with innovation.
Large variations in stock prices happen with sufficient frequency to raise doubts about existing ... more Large variations in stock prices happen with sufficient frequency to raise doubts about existing models, which all fail to account for non-Gaussian statistics. We construct simple models of a stock market, and argue that the large variations may be due to a crowd effect, where agents imitate each other's behavior. The variations over different time scales can be related to
We extend the standard model of general equilibrium with incomplete markets (GEI) to allow for de... more We extend the standard model of general equilibrium with incomplete markets (GEI) to allow for default. Default can be either strategic, or due to ill-fortune. Agents who default are penalized to a degree proportional to the size of their default and to penalty parameters lambda. We find that under conditions similar to those necessary to guarantee the existence of GEI equilibrium, we get the existence of GEI_{lambda} equilibrium, for any lambda > 0. We argue that default is thus reasonably modeled as an equilibrium phenomenon. Moreover, we show that more lenient lambda which encourage default may be Pareto improving because they allow for better risk spreading. When default occurs, the Modigliani-Miller theorem typically fails to hold in our framework.
Is personal currency issued by participants sufficient to operate an economy efficiently, with no... more Is personal currency issued by participants sufficient to operate an economy efficiently, with no outside or government money? Sahi and Yao (in J Math Econ, 1989) and Sorin (in J Econ Theory, 1996) constructed a strategic market game to prove that this is possible. We conduct an experimental game in which each agent issues his/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 The authors are thankful to Benjamin Felt and Ryan Dunn for their labora...
Why people accept intrinsically worthless fiat money in exchange for real goods and services has ... more 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.
Closed exchange and production-and-exchange economies may have multiple equilibria, a fact that i... more 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: society can assign default penalties on fiat money so the economy selects one of the equilibria. Our data show that the choice of default penalty takes the economy to the neighborhood of 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. Additionally we discuss the meaning and experimental implications of default penalties that support an active bankruptcy-modified competitive equilibrium. JEL: C73, C92, D51, E42, G21, G33
We compare general equilibrium economies in which building and maintenance of a depreciating publ... more We compare general equilibrium economies in which building and maintenance of a depreciating public facility is financed either by anonymous voluntary contributions or by taxing agents on their income from private production. Agents start with an endowment of private goods and money, while the government starts with an endowment of public good and money. All private goods produced are tendered for sale in exchange for money in a sell-all market mechanism. Agents' proceeds from sale are taxed, and they individually allocate their private goods between current consumption and investment in production for the following period. The optimal levels of supply of the public good, and tax rate to sustain it over time, are defined and calculated for infinite and finite horizons. These equilibrium theoretical predications are compared to the outcomes of laboratory economies when (1) the starting public facility is either at or below the optimal level; and (2) the tax rate is either exogenously set at the optimal level, or at the median of rates proposed by individual agents. We find that the experimental economies sustain public goods at about 70-90 percent of the infinite horizon but considerably more than the finite horizon optimum. Payoffs (efficiency) is at 90 percent of the infinite horizon equilibrium level even when the rate of taxation is determined by voting. Starting conditions play only a minor role for outcomes of the economies, as efficiency and the stock of public good adjusts to about the same level irrespective of the starting level. These results contrast with rapid decline in provision of public goods under anonymous voluntary contributions, and point to the possibility that the social institution of government enforced taxation may have evolved to address the problem of under-production of public goods through anonymous voluntary contributions.
Is personal credit issued by participants sufficient to operate an economy efficiently, with no o... more Is personal credit issued by participants sufficient to operate an economy efficiently, with no outside or government money? Sorin (1995) constructed a strategic market game to prove that this is possible. We conduct an experimental game in which each agent issues her own 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, or need for trust, the economy operates efficiently at any price level without government money. Conversely, perhaps explanations for prevalence of government money should be sought in either the above mentioned frictions or our unwillingness to experiment with innovation.
Large variations in stock prices happen with sufficient frequency to raise doubts about existing ... more Large variations in stock prices happen with sufficient frequency to raise doubts about existing models, which all fail to account for non-Gaussian statistics. We construct simple models of a stock market, and argue that the large variations may be due to a crowd effect, where agents imitate each other's behavior. The variations over different time scales can be related to
We extend the standard model of general equilibrium with incomplete markets (GEI) to allow for de... more We extend the standard model of general equilibrium with incomplete markets (GEI) to allow for default. Default can be either strategic, or due to ill-fortune. Agents who default are penalized to a degree proportional to the size of their default and to penalty parameters lambda. We find that under conditions similar to those necessary to guarantee the existence of GEI equilibrium, we get the existence of GEI_{lambda} equilibrium, for any lambda > 0. We argue that default is thus reasonably modeled as an equilibrium phenomenon. Moreover, we show that more lenient lambda which encourage default may be Pareto improving because they allow for better risk spreading. When default occurs, the Modigliani-Miller theorem typically fails to hold in our framework.
Is personal currency issued by participants sufficient to operate an economy efficiently, with no... more Is personal currency issued by participants sufficient to operate an economy efficiently, with no outside or government money? Sahi and Yao (in J Math Econ, 1989) and Sorin (in J Econ Theory, 1996) constructed a strategic market game to prove that this is possible. We conduct an experimental game in which each agent issues his/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 The authors are thankful to Benjamin Felt and Ryan Dunn for their labora...
Why people accept intrinsically worthless fiat money in exchange for real goods and services has ... more 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.
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Papers by Martin N Shubik