Sequential equilibrium in monotone games: A theory-based analysis of experimental data

A monotone game is an extensive-form game with complete information, simultaneous moves and an irreversibility structure on strategies. It captures a variety of situations in which players make partial commitments and allows us to characterize conditions under which equilibria result in socially desirable outcomes. However, since the game has many equilibrium outcomes, the theory lacks predictive power. To produce stronger predictions, one can restrict attention to the set of sequential equilibria, or Markov equilibria, or symmetric equilibria, or pure-strategy equilibria. This paper explores the relationship between equilibrium behavior in a class of monotone games, namely voluntary contribution games, and the behavior of human subjects in an experimental setting. Several key features of the symmetric Markov perfect equilibrium (SMPE) are consistent with the data. To judge how well the SMPE fits the data, we estimate a model of Quantal Response Equilibrium (QRE) [R. McKelvey, T. Palfrey, Quantal response equilibria for normal form games, Games Econ. Behav. 10 (1995) 6-38; R. McKelvey, T. Palfrey, Quantal response equilibria for extensive form games, Exp. Econ. 1 (1998) 9-41] and find that the decision rules of the QRE model are qualitatively very similar to the empirical choice probabilities.     

Signaling without a common prior: Results on experimental equilibrium selection

The common prior assumption is pervasive in game-theoretic models with incomplete information. This paper investigates experimentally the importance of inducing a correct common prior in a two-person signaling game. Equilibrium selection arguments predict that different equilibria may be selected depending on whether the common prior is induced or not. Indeed, for a specific probability distribution of the sender?s type, the long-run behavior without an induced common prior is shown to be different from the long-run behavior when a common prior is induced, while for other distributions long-run behavior is similar under both regimes. We also present a learning model that allows players to learn about the other players? strategies and the prior distribution of the sender?s type. We show that this learning model accurately accounts for all main features of the data.     

Global stability condition on the plane: A general law of demand

It is well known that global stability of competitive equilibrium obtains only under quite stringent restrictions. This paper identifies a set of restrictions which may be interpreted as a very weak form of the so-called Law of Demand and shows how this may imply global stability for motion on the plane. It is also of some interest that this condition is satisfied by a perturbed version of the celebrated Scarf example which does not satisfy existing conditions for global stability.     

Unobserved heterogeneity and equilibrium: an experimental study of Bayesian and adaptive learning in normal form games

We describe an experiment based on a simple two-person game designed so that different learning models make different predictions. Econometric analysis of the experimental data reveals clear heterogeneity in the subjects’ learning behavior. But the subjects follow only a few decision rules for basing their play on their information, and these rules have simple cognitive interpretations. There is a unique equilibrium in pure strategies, and many equilibria in mixed strategies. We find that the only equilibrium consistent with the data is one of the mixed strategy equilibria. This equilibrium is shown, surprisingly, to be consistent with Jordan's Bayesian model.     

Short-memory equilibrium in stochastic overlapping generations economies

In stochastic OLG exchange economies, we show that short-memory equilibria—the natural extension from deterministic economies of steady states, low-order cycles, or finite state-space stationary sunspots equilibria—fail to exist generically in utilities. As a result, even with independent and identically distributed exogenous shocks there is serial correlation in endogenous economic variables in equilibrium. This arises even if utilities are time-separable, some goods inferior, and there are no technological lags. Hence, the origins of economic fluctuations can be traced only to the demographic structure of a heterogeneous agent, multiple-good economy.     

Heterogeneous producers facing common shocks: An overlapping-generations example

An analytically tractable model of a competitive, full-information economy is provided in which, for some parameter values, entry and exit over the course of the business cycle is concentrated among small firms. This model is intended to make the logical point that the relatively high sensitivity of small firms to business-cycle fluctuations does not necessarily indicate the presence of informational or incentive constraints in financial markets.     

School choice: an experimental study

We present an experimental study of three school choice mechanisms. The Boston mechanism is influential in practice, while the Gale-Shapley and Top Trading Cycles mechanisms have superior theoretical properties. Consistent with theory, this study indicates a high preference manipulation rate under Boston. As a result, efficiency under Boston is significantly lower than that of the two competing mechanisms in the designed environment. However, contrary to theory, Gale-Shapley outperforms Top Trading Cycles and generates the highest efficiency. Our results suggest that replacing the Boston mechanism with either Gale-Shapley or Top Trading Cycles mechanism might significantly improve efficiency.     

Testing the TASP: An experimental investigation of learning in games with unstable equilibria

We report experiments studying mixed strategy Nash equilibria that are theoretically stable or unstable under learning. The Time Average Shapley Polygon (TASP) predicts behavior in the unstable case. We study two versions of Rock-Paper-Scissors that include a fourth strategy, Dumb. The unique Nash equilibrium is identical in the two games, but the predicted frequency of Dumb is much higher in the game where the NE is stable. Consistent with TASP, the observed frequency of Dumb is lower and play is further from Nash in the high payoff unstable treatment. However, Dumb is played too frequently in all treatments.     

An experimental investigation of wage taxation and unemployment in closed and open economies

We investigate experimentally the economic effects of wage taxation to finance unemployment benefits for a closed economy and an international economy. The main findings are the following. (i) There is clear evidence of a vicious circle in the dynamic interaction between the wage tax and unemployment. (ii) Employment is boosted by budget deficits but subsequent tax rate adjustments to balance the budget lead to employment levels substantially lower than theoretically predicted. (iii) A sales risk for producers due to price uncertainty on output markets appears to cause a downward pressure on factor employment. For labor the wage tax exacerbates this adverse effect.     

Tax and subsidy incidence equivalence theories: experimental evidence from competitive markets

A basic tenet in microeconomics is tax incidence equivalence, which holds that the burden of a unit tax on buyers and sellers is independent of who actually pays the tax. By contrast, policymakers and the public often mistake statutory incidence for economic incidence. Using competitive laboratory markets, I test both tax incidence equivalence and an analogous theorem for subsidies. For sufficiently large markets, the results show strong support for both theories; there is little to no evidence, even in the short run, of the popular misperception that statutory incidence equals economic incidence. In smaller markets in which competitive forces are weaker and relative bargaining strengths may play a role, the evidence for tax incidence equivalence is weaker as minor price discrepancies may persist between markets.     

On the uniqueness of competitive equilibrium

Summary . The paper is concerned with the following question: in addition to local uniqueness, what other conditions must be imposed to ensure global uniqueness of competitive equilibrium? The answer is provided within a standard framework involving excess demand functions. Conditions are identified which have the nice property that they are true close to a regular equilibrium. Uniqueness is established by considering an adjustment process and showing that under the mentioned conditions, every equilibrium is locally asymptotically stable and moreover the process itself is globally stable; uniqueness follows from an Arrow and Hahn (1971) result. Alternatively, the paper may be seen as identifying conditions under which there is a vectorfield satisfying the requirements of an uniqueness result due to Dierker (1974). Received: July 1, 1996; revised version October 7, 1996     

General equilibrium, markets, macroeconomics and money in a laboratory experimental environment

Summary. This paper reports on the use of laboratory experimental techniques to create relatively complete economic systems. The creation of these market systems reflects a first attempt to explore the nature of inherently interdependent environments and to assess the ability of simultaneous equations equilibrium models like the classical static general competitive equilibrium model, to predict aspects of system behaviors. In addition, the impact of the quantity of a fiat money was studied. The economies were successfully created. Classical models capture much of what was observed. Received: May 21, 1996; revised version: May 21, 1997     

Estimated general equilibrium models for the evaluation of monetary policy in the US and Europe

In this paper we derive a general equilibrium model based on optimising behaviour, which also implies a data consistent framework for monetary policy analysis. Specifically, our model accounts for nominal inertia in both price and wage setting as well for habits in consumption. Using US and European data from 1970 to 1998 our parameter estimates reveal that (i) price contracts last for 8 months and 13 months in the US and Euro-area, respectively; (ii) wage contracts have a length of 7 months and 1.75 years in the US and Europe, respectively; (iii) the extent of backward-looking behaviour in price setting is statistically significant in both economies with 41% of price contracts in the US and 28% in the Euro-area set according to a simple rule-of-thumb; (iv) backward-looking wage setting is only present in Europe with 17% of contracts set in a backward-looking manner; and (v) similar habits effects are present in both European and US consumption. Finally, we simulate the effects of monetary policy by considering the impact of a 1 point increase in nominal interest rates for one quarter. Our parameter estimates imply that there is a relatively muted inflationary response to interest rate increases in Europe (price inflation falls by -0.08% in Europe and 0.11% in the US) and there is a correspondingly large output response (-0.2% in the US and -0.6% in Europe).     

Externalities and fundamental nonconvexities: A reconciliation of approaches to general equilibrium externality modeling and implications for decentralization

Starrett (1972) [33] and Boyd and Conley (1997) [7] approaches to externality modeling are unified by distinguishing between producible and nonproducible public commodities. Nonconvexities are associated with detrimental producible public commodities but not with nonproducible public commodities in Boyd and Conley (1997) [7]. Disposability properties (costly or costless) imply that producible public commodities are either by-products (e.g., pollution) or joint-products (e.g., national defense). Markets fail for both beneficial and detrimental by-products. Nonconvexities imply that price-based equilibria, e.g., Pigovian tax equilibrium, may not be Pareto-efficient. Foley's (1967, 1970) [17] and [18] “public competitive equilibrium” combines price and quantity signals with a unanimity criterion and restores the equivalence between equilibrium and efficiency.     

Ascending price Vickrey auctions for general valuations

Ascending price auctions involving a single price path and buyers paying their final bid price cannot achieve the Vickrey-Clarke-Groves (VCG) outcome in the combinatorial auctions setting. Using a notion called universal competitive equilibrium prices, shown to be necessary and sufficient to achieve the VCG outcome using ascending price auctions, we define a class of ascending price auctions in which buyers bid on a single price path. Truthful bidding by buyers is an ex post Nash equilibrium in such auctions. By giving discounts to buyers from the final price, the VCG outcome is achieved for general valuations.     

Corrigendum to “School choice: An experimental study” [J. Econ. Theory 127 (1) (2006) 202-231]

We correct an inconsistency in the efficiency comparison reported in [Y. Chen, T. Sönmez, School choice: An experimental study, J. Econ. Theory 127 (1) (2006) 202-231]. The efficiency comparison of the three school choice mechanisms in our paper is based on recombinant estimation with an identical set of 10 tie-breakers, while the statistics reported in Table 7 is computed using 14,400 tie-breakers.     

Pursuing the wrong options? Adjustment costs and the relationship between uncertainty and capital accumulation

Abel and Eberly (1999) prove that uncertainty has an ambiguous effect on long run capital accumulation in a real options model. We show that, with adjustment costs quadratic in investment, more uncertainty reduces capital and this effect may be large.     

On linking microsimulation and computable general equilibrium models using exact aggregation of heterogeneous discrete-choice making agents

Our paper contributes by bridging the gap between the (partial equilibrium) microsimulation and the computable general equilibrium (CGE) approaches, by making use of exact aggregation results from the discrete choice literature: heterogeneous individuals choosing within a set of discrete alternatives may be aggregated into a representative agent with (possibly multiple-level) constant elasticity-of-substitution/transformation preferences/technologies. These results therefore provide a natural link between the two policy evaluation approaches. We illustrate the usefulness of these results by evaluating potential effects of population ageing on the dynamics of income distribution and inequalities, using a simple overlapping generations model where individuals make leisure/work decisions, and choose a profession among a discrete set of alternatives.     

Another look at the linear q model: an empirical analysis of aggregate business capital spending with maintenance expenditures

Abstract .  The paper revisits the empirical investment literature, which has established that aggregate business fixed investment is not found to be related linearly to marginal or average Tobin's q . The theoretical background is extended here by developing a supply-side model where the depreciation rate of private capital is determined endogenously. The firm can either invest in 'new' capital, which adds directly to the existing capital stock at the presence of convex adjustment costs, or extend the durability of installed capital through maintenance expenditure, which affects its depreciation rate. The model shows that Tobin's q is then a positively related sufficient statistic for both components of aggregate capital expenditures. This central implication is tested empirically using aggregate time-series survey data from Canada on 'new' investment and maintenance expenditures covering the period 1956–93. The estimated relationships produce significant and plausible parameter estimates for the structural parameters of the q model.     

The impact of the 2008 German corporate tax reform: A dynamic CGE analysis

In this paper we develop the dynamic CGE model, ifoMod, which is designed to analyse the impact of fundamental tax reforms and in particular capital income tax reforms for Germany. The model is in line with neoclassical growth theory and features all important behavioural interactions between the four major building blocks of an economy including the firm and household sector, the government and the rest of the world. We consider firms of different legal forms which all face an intertemporal investment problem, a financing problem w.r.t. the optimal choice of debt and equity financing as well as a factor input problem when deciding on the optimal amount of different skill types of labour employed. We show the impact of different types of taxes on the behavioural margins of firms and households. The conducted simulation shows the impact of the latest German corporate tax reform of 2008 on the German macroeconomic variables such as investments, GDP, consumption and household's welfare.