《神曲》中的两希文化对立与融合

但丁的《神曲》既浸透了宗教意识,又饱含了生命的热情。翻开《神曲》,我们可以看出,面对两希文化各有千秋的局面,但丁显得十分热切,但又带点茫然。但丁的《神曲》为两希文化的融合作出了一次伟大的尝试。从《神曲》中所反映出来的两希文化对立和融合出发,深入探讨了两种不同文化对作品的影响。     

Unique Implementation of the Full Surplus Extraction Outcome in Auctions with Correlated Types

In auctions with correlated types it is possible to design mechanisms such that full surplus extraction can be obtained as the outcome of an equilibrium in which agents use (weakly) dominant strategies. However, it is not assured that the outcome is unique. We present an example in which no mechanism can yield the full surplus extraction outcome as the unique Bayesian equilibrium outcome. Next we show that in the standard auction model the multiplicity problem can be fully resolved using sequential mechanisms, i.e., we show that it is possible to obtain the full surplus extraction outcome as the unique perfect Bayesian equilibrium outcome.Journal of Economic LiteratureClassification Numbers: D44; D70.     

Union–firm bargaining: Order of play and efficiency

This paper shows that a modified alternating offers Rubinstein model can provide a Pareto superior outcome in the context of the right-to-manage union–firm bargaining. Two examples of bargaining protocols that yield a superior outcome are provided. In the first example, the parties engage in a game in which the order of play is determined as part of the bargaining. We show that the game has a unique subgame perfect equilibrium in which the firm always moves first in the wage bargaining game. The equilibrium wage is, therefore, unique. In the second example, we examine a two-part-tariff alternating offers bargaining protocol, where the parties bargain over the wage and transfer payments. We show that this bargaining protocol has a Pareto efficient, unique subgame perfect equilibrium. Thus, although the parties do not bargain over the level of employment, the outcome under this protocol is, nevertheless, socially optimal.     

Franz Mueller,eminent social economist

Taken from the remarks made at the presentation of the Divine Award at the ASE Presidential Breakfast, December 29, 1987, Chicago.     

Bargaining and markets: complexity and the competitive outcome

Rubinstein and Wolinsky (Rev. Econ. Stud. 57 (1990) 63-78) consider a simple decentralised market game in which agents meet randomly or voluntarily and bargain over the terms of trade. They show that any individually rational price can be sustained as a sequential equilibrium even though the model has a unique competitive outcome. Here, I consider Rubinstein and Wolinsky's model and show that if complexity costs of implementing strategies enter players’ preferences, together with the standard payoff in the game, then every equilibrium is stationary/Markov and induces the unique competitive price. Thus, I demonstrate that aversion to complexity may provide a justification for the competitive outcome.     

Protecting Minorities through the Average Voting Rule

In the average voting rule, the outcome is some weighted average of votes. The unique average voting outcome is characterized by a median formula, which depends on voters' preferred allocations and some parameters constructed from voters' weights. A minority is said to be protected by a switch in voting rule if the outcome becomes closer to the median bliss point of the minority. Sufficient conditions for minority protection are that, either the minority's weight is sufficiently large or the majority outcome is too unfavorable to the minority. Applications to the composition of public goods and to public expenditures level are considered. We explore the combined use of average and majority voting in a two‐stage procedure for determining the level and the composition of public expenditures.     

Asymmetric information and rationalizability

We study how asymmetric information affects the set of rationalizable solutions in a linear setup where the outcome is determined by forecasts about this same outcome. The unique rational expectations equilibrium is also the unique rationalizable solution when the sensitivity of the outcome to agents’ forecasts is less than one, provided that this sensitivity is common knowledge. Relaxing this common knowledge assumption, multiple rationalizable solutions arise when the proportion of agents who know the sensitivity is large, and the uninformed agents believe it is possible that the sensitivity is greater than one. Instability is equivalent to existence of some kind of sunspot equilibria.     

Demand bargaining and proportional payoffs in majority games

We study a majoritarian bargaining model in which players make payoff demands in decreasing order of voting weight. The unique subgame perfect equilibrium outcome is such that the minimal winning coalition of the players that move first forms with payoffs proportional to the voting weights. This result advances previous analysis in terms of one or more of the following: a) the simplicity of the extensive form (finite horizon with a predetermined order of moves); b) the range of the majority games covered; c) the equilibrium concept (subgame perfect equilibrium is sufficient for a unique prediction).     

Dominance solvability of dynamic bargaining games

We formulate and study a general finite-horizon bargaining game with simultaneous moves and a disagreement outcome that need not be the worst possible result for the agents. Conditions are identified under which the game is dominance solvable in the sense that iterative deletion of weakly dominated strategies selects a unique outcome. Our analysis uses a backward induction procedure to pinpoint the latest moment at which a coalition can be found with both an incentive and the authority to force one of the available alternatives. Iterative dominance then implies that the alternative characterized in this way will be agreed upon at the outset—or, if a suitable coalition is never found, that no agreement will be reached.     

Payoff dominance and risk dominance in the observable delay game: a note

We examine whether the payoff dominant sequential-move (Stackelberg) outcome is realized when timing is endogenized. We adopt the observable delay game formulated by Hamilton and Slutsky [Games Econ Behav 2(1):29–46, 1990]. We find that if one sequential-move outcome is payoff dominant, either (i) the outcome both players prefer is the unique equilibrium; or (ii) two sequential-move outcomes are equilibria and the one both players prefer is risk dominant. In other words, no conflict between payoff dominance and risk dominance in the observable delay game exists, in contrast to other games such as (non pure) coordination games. We also find that even if one of two sequential-move outcomes is the unique equilibrium outcome in the observable delay game, it does not imply that the equilibrium outcome is payoff dominant to the other sequential-move outcome.      

Endogenous Growth Cycles in Continuous Time

The endogenous dynamics of a closed constant returns multi-market economy are examined in which agents face downward sloping demand. The trigger for growth in this model is a technological change that warrants costly adjustment in input quantities by agents. In the resulting dynamic game, relative prices within markets remain constant. Consequently, all own price elasticities are constant. In markets characterized by lower cost of capital the unique outcome is collusion in which agents do not incur adjustment cost and there is no adoption of new technology. But in other markets a unique non-cooperative equilibrium exists in which agents do incur the cost of adopting the new technology. Only three specifications of adjustment costs are feasible. Output increases along an S-shaped time path with or without a non-explosive cyclical component.     

Efficient Allocations with Hidden Income and Hidden Storage

We consider an environment in which individuals receive income shocks that are unobservable to others and can privately store resources. We provide a simple characterization of the unique efficient allocation of consumption in cases in which the rate of return on storage is sufficiently high or, alternatively, in which the worst possible outcome is sufficiently dire. We show that, unlike in environments without unobservable storage, the symmetric efficient allocation of consumption is decentralizable through a competitive asset market in which individuals trade risk-free bonds among themselves.     

Matching markets with adverse selection

This paper considers a market with adverse selection in the spirit of Rothschild and Stiglitz (Quart. J. Econ. 90 (1976) 629). The major departure from existing approaches is that we model a decentralized market that is open-ended and constantly refilled by new participants, e.g., by new workers and firms in the case of a labor market. The major novelty of this approach is that the distribution of types in the market becomes an endogenous variable, which is jointly determined with equilibrium contracts. As frictions become small, we show that the least-cost separating contracts are always supported as an equilibrium outcome, regardless of the distribution of types among entrants. Moreover, we derive conditions under which this outcome is also unique.     

Authority and communication in the laboratory

We report findings from experiments on two delegation–communication games. An uninformed principal chooses whether to fully delegate her decision-making authority to an informed agent or to retain the authority and communicate with the agent via cheap talk to obtain decision-relevant information. In the game in which the delegation outcome is payoff-dominated by both the truthful and the babbling communication outcomes, we find that principal-subjects almost always retain their authority and agent-subjects communicate truthfully. Significantly more choices of delegation than of communication are observed in another game in which the delegation outcome payoff-dominates the unique babbling communication outcome; yet there is a non-negligible fraction of principal-subjects who holds on to their authority and agent-subjects who transmits some information. A level-k analysis of the game indicates that a principal-subject “under-delegates” due to the belief that her less-than-fully-strategic opponent will provide information; such belief is in turn consistent with the actual play.     

Endogenous timing in tax competition: The effect of asymmetric information

This study explores the effects of asymmetric information on endogenous leadership in a simple tax competition environment. The study models a two-country economy where one country is informed about its own and opponent's productivity of private goods, while the other country only knows its productivity. The results show that each type of informed country has an incentive to pretend to be the other type, which leads to a Stackelberg outcome endogenously, while the simultaneous move is the unique outcome under complete information. Under the Stackelberg outcome, the uninformed country moves first and the informed country moves second. Moreover, ex-post social welfare under asymmetric information can become larger than that under complete information, because the uninformed country chooses a less aggressive tax rate under asymmetric information. These results depend on the type of uncertainty, and capital ownership and share.     

Coordinating development: Can income-based incentive schemes eliminate Pareto inferior equilibria?

Individuals' inability to coordinate investment may significantly constrain economic development. In this paper we study a simple investment game characterized by multiple equilibria and ask whether an income-based incentive scheme can uniquely implement the high-investment outcome. A general property of this game is the presence of a crossover-investment point at which an individual's incomes from investment and non-investment are equal. We show that arbitrarily small errors in the government's knowledge of this crossover point can prevent unique implementation of the high-investment outcome. We conclude that informational requirements are likely to severely limit a government's ability to use income-based incentive schemes as a coordination device.     

The principal-agent problem with a satisficing agent

The principal-agent problem is formulated with an expected utility maximizing principal and a satisficing agent. If the outcome set is finite and if there is only one aspiration level, then there are always optimal incentive schemes which can be represented by vectors having only the unique aspiration level and zero as coordinate values. The relation between the monotone likelihood ratio property and the monotonicity of optimal incentive schemes is investigated. This is done not only in the above model, but also in a continuous model with outcomes in an interval, which is much more interesting.     

A strategic implementation of the Average Tree solution for cycle-free graph games

In this note we provide a strategic implementation of the Average Tree solution for zero-monotonic cycle-free graph games. That is, we propose a non-cooperative mechanism of which the unique subgame perfect equilibrium payoffs correspond to the average hierarchical outcome of the game. This mechanism takes into account that a player is only able to communicate with other players (i.e., to make proposals about a division of the surplus of cooperation) when they are connected in the graph.     

Collective choice with endogenous reference outcome

A collective choice problem—essentially a bargaining problem without disagreement outcome—is studied. An extended solution, which determines a solution and a reference point simultaneously, is characterized. The unique extended solution that meets the extended versions of Pareto-optimality, independence of irrelevant alternatives, symmetry, and scale invariance maximizes the Nash product with respect to both the solution and the reference point.     

Bargaining and Boldness

We study a multiperson bargaining problem with general risk preferences through the use of Shaked's game of cycling offers with exogenous breakdown. If preferences are “smooth,” then as the risk of breakdown vanishes, the limiting outcome is one in which bargainers are equally marginally bold; where a bargainer's marginal boldness measures his willingness to risk disagreement in return for a marginal improvement in his position. Under smoothness, any (ordinal-)Nash solution is an equally marginally bold outcome. However, unlike the concept of the (ordinal-)Nash solution, a unique equally marginally bold outcome exists in natural cases—in particular, if all bargainers have risk-averse preferences of the rank-dependent expected utility type. For these preferences, the equally marginally bold outcome maximizes a “bargaining power”-adjusted (asymmetric) Nash product where the degree of asymmetry is determined by the disparity in the marginal valuation of certainty among bargainers. Journal of Economic Literature Classification Numbers: C72, C78, D81.