Price Dynamics in an Exchange Economy

The pure exchange model is the foundation of the neoclassical theory of value, yet equilibrium predictions and models of price adjustment for this model remained untested prior to the experiment reported in this paper. With the exchange economy replicated several times, prices and allocations converge sharply to the competitive equilibrium in continuous double auction (CDA) trading. Convergence is evaluated by comparing the extent of price adjustment within each market replication (or trading period) to the extent of adjustment across trading periods: most observed price adjustment occurs within trading periods, so price adjustment data are evaluated with the Hahn process model (Hahn and Negishi [1962]), which is a disequilibrium model of within-period trades. Estimation demonstrates that the model is consistent with observed price paths within each period of the exchange economy. The model is augmented with an additional assumption – based on observations from this experiment – that the initial trade price in period t+1 is randomly drawn from the interval between the minimum and maximum trade prices in period t. The estimated within-period adjustment rule, combined with this across-period adjustment rule, generates price paths similar to data from an experiment session.Competitive equilibrium, disequilibrium dynamics, continuous double auction, experimental economics, exchange economy, Hahn process, neoclassical theory of value, tatonnement, unit root tests

Housing Market Price Tier Movements in an Expansion and Collapse

The subprime mortgage crisis has done more damage to the financial system than any financial crisis since the depression. This paper examines the Federal Reserve’s expansionary monetary policy during the early part of this decade, the effect of that expansionary policy on mortgage market liquidity, the effects of that liquidity on housing price movements, and the way that those price movements contributed to the severity of the financial crisis. House prices increased most in the low-priced tier of the market during the expansion, which prompted lenders and investors in mortgage-backed securities to finance highly leveraged purchases in this segment of the market. But house prices also decline most in the low-priced tier during a contraction or collapse, among borrowers with inadequate assets and income to absorb the decline in their home values if forced to sell their homes. Consequently, their losses were transmitted into the financial sector, with an impact far more devastating than in any crisis since the depression. In order to address this structural vulnerability of the residential real estate market, several problems with incentives and information disclosure at almost every stage in the lending and securitization process need to be addressed, including the incentives of home buyers, loan originators, loan servicers, bond rating firms, investment banks, and credit enhancement providers. Alternatively, many of the problems with risk assessment may need to be transferred to investors, who have a clear incentive to gather information and assess risks, and can discipline lenders by directing capital to those lenders who adequately manage lending risks.

The Strategic Impact of Pace in Double Auction Bargaining

This paper evaluates performance of human subjects and instances of a bidding model that interact in continuous ­time double auction experiments. Asks submitted by instances of the seller model (``automated sellers'') maximize the seller's expected surplus relative to a heuristic belief function, and arrive stochastically according to an exponential distribution. Automated buyers are similar. Across experiment sessions we vary the exponential distribution parameters of automated sellers and buyers in order to assess the impact of the relative pace of asks and bids on the performance of both human subjects and the automated sellers and buyers. In these experiments, prices converge and allocations converge to efficiency, yet the split of surplus typically differs significantly from the equilibrium split. In order to evaluate the impact of pace, a statistical model is developed in which the relative performance of sellers to buyers is examined as a function of the profile of types present in each experiment session. This econometric model demonstrates that (1) human buyers outperform human sellers, (2) automated sellers and buyers with a longer expected time between asks or bids outperform faster automated sellers and buyers, and (3) the performance of the faster automated buyers is comparable to that of human buyers.Double auction, experimental economics, bounded rationality

Risk Aversion, Beliefs, and Prediction Market Equilibrium

Manski [2004] analyzes the relationship between the distribution of traders’ beliefs and the equilibrium price in a prediction market with risk neutral traders. He finds that there can be a substantial difference between the mean belief that an event will occur, and the price of an asset that pays one dollar if the event occurs and otherwise pays nothing. This result is puzzling, since these markets frequently produce excellent predictions. This paper resolves the apparent puzzle by demonstrating that both risk aversion and the distribution of traders’ beliefs significantly affect the equilibrium price. For coeffcients of relative risk aversion near those estimated in empirical studies and for plausible belief distributions, the equilibrium price is very near the traders’ mean belief.Asset pricing, beliefs, competitive equilibrium, prediction markets, risk aversion

Market Dynamics in Edgeworth Exchange

Edgeworth exchange is the fundamental general equilibrium model, yet equilibrium predications and theories of price adjustment for this model remain untested. This paper reports an experimental test of Edgeworth exchange which demonstrates that prices and allocations converge sharply to the competitive equilibrium. Price convergence is evaluated with the tatonnement model, interpreted as a disequilibrium model of across- period price adjustment. Subsequently, the extent of within-period adjustment is compared to that of across-period adjustment. Since most observed price adjustment occurs within trading periods, price adjustment data is evaluated with two disequilibrium models of within- period trades. These models are the Geometric Mean model, which is formulated in this paper, and the Hahn process (Hahn and Negishi [1962]). Price dynamics from experiment sessions fit the Geometric Mean model better than the Hahn process, and in addition, the Geometric Mean model provides direction for development of an Edgeworth exchange bargaining model.Competitive equilibrium, disequilibrium dynamics, double auction, Edgeworth exchange, experimental economics, exchange economy, Hahn process, market dynamics

The Edgeworth exchange formulation of bargaining models and market experiments

We construct Edgeworth exchange economies equivalent to demand and supply environments typically used in bargaining models and market experiments. This formulation clearly delineates environment, institution, and behavior for these models and experiments. To illustrate, we examine results by Gode and Sunder, who simulate random behavior in a double auction and argue that this institution leads to an efficient allocation, even in the absence of rationality. We use the Edgeworth exchange representation of their economic environment to demonstrate that they model individually rational behavior, and show that their model is a special case of theoretical results by Hurwicz, Radner, and Reiter.Double auction, Market experiment, Edgeworth exchange, Bounded rationality

Individual Rationality and Market Efficiency

The demonstration by Smith [1962] that prices and allocations quickly converge to the competitive equilibrium in the continuous double auction (CDA) was one of the first – and remains one of the most important results in experimental economics. His initial experiment, subsequent market experiments, and models of price adjustment and exchange have added considerably to our knowledge of how markets reach equilibrium, and how they respond to disruptions. Perhaps the best known model of exchange in CDA market experiments is the random behavior in the “zero-intelligence” (ZI) model by Gode and Sunder [1993]. They conclude that even without trader rationality the CDA generates efficient allocations and “convergence of transaction prices to the proximity of the theoretical equilibrium price,” provided only that agents meet their budget constraints. We demonstrate that – by any reasonable measure – prices don’t converge in their simulations. Their budget constraint requires that a buyer’s currency never exceeds her value for the commodity, which is an unnatural restriction. Their conclusion that market efficiency results from the structure of the CDA independent of traders’ profit seeking behavior rests on their claim that the constraints that they impose are a part of the market institution, but this is not so. We show that they in effect impose individual rationality, which is an aspect of agents' behavior. Researchers on learning in markets have been misled by their interpretation of the ZI simulations, with deleterious effects on the debate on market adjustment processes.Bounded rationality; double auction; exchange economy; experimental economics; market experiment; "zero intelligence" model

Gross domestic product and its components in recessions

The recent economic crisis – already deservedly labeled the ‘great recession’ – continues to plague the health of the economy as a whole and has motivated us to probe its characteristic features and compare it to the typical economic downturn. Events during the boom and crash have been sharply delineated, progressing from (1) an unprecedented housing price bubble from 1997 to 2006, (2) rapid house price decline beginning early in 2007, (3) freezing of credit markets in August 2007, (4) rapid declines in equities prices and economic output by the middle of 2008, and (5) deterioration of the financial system in 2008 and an aggressive and unprecedented Federal Reserve intervention in the fall of 2008. This sequence of events has provided a fresh perspective with which to examine past economic cycles, and, we believe, is likely to change how economists, policy makers, investors, and others think about monetary policy, housing cycles, and business cycles. We find that eleven of the most recent fourteen economic downturns in the U.S. – from the great depression that began in 1929 to the great recession starting in late 2007 – were led by declines in housing investment. In these eleven downturns, housing investment declined before any other major component of GDP and its total decline before and during the recession was larger in percentage terms than the decline in any other major sector. In the 1945 recession – one of the three recessions in which housing was not implicated – national defense expenditures fell while all major components of private expenditure rose. The other two – in 1937-38 and 2001 – resulted primarily from declines in non-residential fixed investment that preceded and exceeded declines in any other major component of GDP. Figure 1 shows the percentage of GDP contributed by housing expenditures over the past 81 years. Although housing is not a large component of GDP – which may explain its limited role in accounts of recessions – it is volatile, it has declined before almost every recession, it has rarely declined substantially without a recession following soon afterward, and the extent of its decline emerges as a good predictor of the depth and duration of the recession that follows.2 In addition to its role as a leading indicator, and its volatility over the business cycle, housing investment has recovered faster than any other sector of the economy in every recession since 1921, with the single exception of the 1980 recession, which lasted only 12 months.

Bondholder Reorganization of Systemically Important Financial Institutions

This paper describes a resolution process for faltering financial firms that quickly allocates losses to bondholders and transfers ownership of the firm to them. This process overcomes the most serious flaws in resolution plans submitted by banks under Dodd-Frank Title I and in the FDIC receivership procedure in Dodd-Frank Title II by restoring the balance sheet of a failing financial institution and immediately replacing the management and board of directors who allowed its demise. In almost all bank failures, this process would eliminate the need for government involvement beyond court certification of the reorganization. The procedure overcomes the serious incentive distortions and inefficiencies that result from bailouts, and avoids the destruction of value and financial market turmoil that would result from the bankruptcies and liquidations that Dodd-Frank requires for distressed and failing banks

A Tractable Model of Reciprocity and Fairness

We introduce a parametric model of other-regarding preferences. The income distribution and the kindness or unkindness of others' choices ('intentions') systematically affect a person's emotional state. The emotional state systematically affects the marginal rate of substitution between own and others' payoffs, and thus the person's subsequent choices. The model is applied to two sets of laboratory data: simple binary choice mini-ultimatum games, and Stackelberg duopoly games with a range of choices. The results confirm that other-regarding preferences respond to others' intentions as well as to the income distribution.