Price-quantity Mechanisms Research Articles

Comparing policies to confront permit over-allocation

Instability in cap-and-trade markets, particularly with respect to permit price collapses, has been an area of concern for regulators. To that end, several policies, including hybrid price-quantity mechanisms and the newly introduced “market stability reserve” (MSR) systems, have been introduced and even implemented in some cases. I develop a stochastic dynamic model of a cap-and-trade system, parameterized to values relevant to the European Union׳s Emission Trading System (EU ETS) to analyze the performance of these policies aimed at adding stability to the system or at least at reducing perceived over-allocations of permits. Results suggest that adaptive-allocation mechanisms such as a price collar or MSR can reduce permit over-allocations and permit price volatility in a more cost-effective manner than simply reducing scheduled permit allocations. However, it is also found that the performance of these adaptive allocation policies, and in particular the MSR, are greatly affected by assumed discount rates and policy parameters.

Comparing Policies to Confront Permit Over-Allocation

Instability in cap-and-trade markets, particularly with respect to permit price collapses has been an area of concern for regulators. To that end, several policies, including hybrid price-quantity mechanisms and the newly introduced market stability reserve (MSR) systems have been introduced and even implemented in some cases. I develop a stochastic dynamic model of a cap-and-trade system, parameterized to values relevant to the European Union's Emission Trading System (EU ETS) to analyze the performance of these policies aimed at adding stability to the system or at least at reducing perceived over-allocations of permits. Results suggest adaptive-allocation mechanisms such as a price collar or MSR can reduce permit over-allocations and permit price volatility in a more cost-effective manner than simply reducing scheduled permit allocations. However, it is also found that the performance of these adaptive allocation policies, and in particular the MSR, are greatly affected by assumed discount rates and policy parameters.

Natural Implementation with Partially Honest Agents in Economic Environments with Free-Disposal

We study Nash implementation by natural price-quantity mechanisms in pure exchange economies with free-disposal (Saijo et al., 1996, 1999) where agents have weak/strong intrinsic preferences for honesty (Dutta and Sen, 2012). Firstly, the Walrasian rule is shown to be non-implementable where all agents have weak (but not strong) intrinsic preferences for honesty. Secondly, the class of efficient allocation rules that are implementable is identifi?d provided that at least one agent has strong intrinsic preferences for honesty. Lastly, the Walrasian rule is shown to belong to that class.

Natural implementation with partially-honest agents in economic environments with free-disposal

We study Nash implementation by natural price-quantity mechanisms in pure exchange economies with free-disposal (Saijo et al., 1996, 1999) where agents have weak/strong intrinsic preferences for honesty (Dutta and Sen, 2012). Firstly, the Walrasian rule is shown to be non-implementable where all agents have weak (but not strong) intrinsic preferences for honesty. Secondly, the class of e¢ cient allocation rules that are implementable is identi…ed provided that at least one agent has strong intrinsic preferences for honesty. Lastly, the Walrasian rule is shown to belong to that class.

Natural Implementation with Partially Honest Agents

In this paper, we introduce the weak and the strong notions of partially honest agents (Dutta and Sen, 2012), and then study implementation by natural price-quantity mechanisms (Saijo et al., 1996, 1999) in pure exchange economies with three or more agents in which pure-consequentialistically rational agents and partially honest agents coexist. Firstly, assuming that there exists at least one partially honest agent in either the weak notion or the strong notion, the class of efficient social choice correspondences which are Nash-implementable by such mechanisms is characterized. Secondly, the (unconstrained) Walrasian correspondence is shown to be implementable by such a mechanism when there is at least one partially honest agent of the strong type, which may provide a behavioral foundation for decentralized implementation of the Walrasian equilibrium. Finally, in this set-up, the effects of honesty on the implementation of more equitable Pareto optimal allocations can be viewed as negligible.

Nash-implementation of competitive equilibria via a bounded mechanism

We deal with the problem of providing incentives for the implementation of competitive outcomes in a pure-exchange economy with finitely many households. We construct a feasible price-quantity mechanism, which fully implements Walras equilibria via Nash equilibria in fairly general environments. Traders’ preferences need neither to be ordered nor continuous. In addition, the mechanism is such that no pure strategy is weakly dominated, hence is bounded (in the sense of Jackson 1992). In particular it makes no use of any integer game.

A Price-Quantity Mechanism to Implement Lindahl Allocations with Forthrightness

Un mécanisme en prix et quantité pour décentraliser les allocations de Lindahl de manière transparente Cet article propose un nouveau mécanisme en prix et quantité, tel que le jeu associé décentralise des allocations de Lindahl en équilibre de Nash. Nous montrons qu’il vérifie la propriété de déclaration franche ( forthrightness ), introduite par Saijo et al. [1996]. En effet, à l’équilibre de Nash, chaque joueur annonce directement et honnêtement son prix personnalisé et sa demande de bien public, et obtient l’allocation économique correspondante. Dans le cas d’une économie quasi-linéaire, nous montrons que l’équilibre de Nash du jeu est globalement stable, en formalisant le comportement hors équilibre des joueurs comme un processus du gradient.

Natural Implementation with Partially-Honest Agents

The paper proposes necessary and su¢ cient conditions for the natural implementation of (e¢ cient) social choice correspondences (SCCs) in pure …nite exchange economies when some of the agents are partially honest. A partially honest agent is an agent who strictly prefers to tell the truth when lying has no better material consequences for her. Firstly, it is shown that if there is even one partially honest agent in the economy (and the planner does not know her identity), then any SCC is Nash implementable by a natural price-allocation mechanism. Secondly, and in sharp contrast with the results of conventional models of natural implementation, it is shown that the equivalence relationship between natural price-allocation mechanisms and natural price-quantity 2 mechanisms no longer holds. Finally, and even more strikingly, the paper reports that the class of implementable SCCs by natural price-quantity mechanisms is signi…cantly enlarged.

Efficiency and imperfect competition with incomplete markets

We deal with the problem of providing incentives for the implementation of constrained optimal outcomes in a two-period economy with incomplete markets. Allowing both for price observation, price-manipulation and a minimal amount of coordination enables to recover (second-best) efficiency at equilibrium, therefore to do better than perfect competition. To make this point, we construct a feasible price-quantity mechanism for two-period economies. In the absence of monitoring between the first and the second period, one gets a full implementation of the (typically inefficient) GEI equilibria via Nash equilibria. By contrast, when actions are observed between the two periods, a large subset of feasible and individually rational allocations can be obtained as strategic equilibria. Furthermore, the correspondence of individually rational, second-best efficient outcomes is implemented via undominated Nash equilibria (NE).

A characterization of natural and double implementation in production economies

We define two types of natural mechanisms, quantity and price-quantity types, in convex production economies, and characterize the class of Pareto subsolutions doubly implementable in Nash and strong Nash equilibria by these mechanisms respectively. First, we show that there is a class of Pareto subsolutions doubly implementable by natural quantity mechanisms, as long as production sets have smooth boundaries. We characterize the class of Pareto subsolutions doubly implementable by natural price-quantity mechanisms without assuming differentiability of utility functions. Third, we show that the Walrasian solution is the unique Pareto and fully individually rational solution naturally and doubly implementable in private ownership economies.

Characterizing Natural Implementability: The Fair and Walrasian Correspondences

We characterize natural implementability in exchange economies when a social choice correspondence possibly recommends a Pareto efficient allocation where the common marginal rate of substitution is not determined uniquely. We find that the no-envy and efficient (or fair) correspondence cannot be implemented by any natural mechanism with a price and a quantity announcement, but can be implemented by a natural mechanism with a price and two-quantity announcement. On the other hand, the constrained Walrasian correspondence can be implemented by a natural price-quantity mechanism with budget balance. Journal of Economic Literature Classification Numbers: C72, D51, D63, D78.

Toward Natural Implementation

The authors identify some fundamental conditions that a 'natural' mechanism should satisfy in exchange economies. First, they provide necessary and sufficient conditions for social choice correspondences to be implemented in Nash equilibria by natural mechanisms. Second, they show that the class of social choice correspondences implementable by (price and) two-quantity mechanisms is equivalent to the class of social choice correspondences implementable by (price and) allocation mechanisms. Third, the authors find that the no-envy correspondence is implementable by a two-quantity mechanism and the fair correspondence is implementable by a price-quantity mechanism. Copyright 1996 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.