The Role of Absolute Continuity in “Merging of Opinions” and “Rational Learning”

D. Blackwell and L. Dubins (1962, Ann. Math. Statist.38, 882–886) showed that opinions merge when priors are absolutely continuous. E. Kalai and E. Lehrer (1993, Econometrica61, 1019–1045) use this result to show that players in a repeated game eventually play like a Nash equilibrium. We provide an alternative proof of merging of opinions that clarifies the role of absolute continuity while casting doubt on the relevance of the result. Persistent disagreement, the opposite of merging, allows the construction of a sequence of mutually favorable “bets.” By a law of large numbers, both agents are certain they will win these bets on average. This certain disagreement violates absolute continuity. Journal of Economic Literature Classification Numbers: C11, C69, C72, D83.     

ON ADDITIVE METHODS TO SHARE JOINT COSTS*

The Shapley value theory is extended to cost functions with multiple outputs (or to production functions with multiple inputs) where each output is demanded by a different agent and the level of demand varies. Beyond the Additivity and Dummy axioms (Shapley's original axioms) we insist that the cost-share of an agent should not decrease when she increases her demand (Demand Monotonicity). This property rules out the Aumann-Shapley pricing formula, as well as any method charging average cost for homogeneous goods. We characterize the class of cost sharing methods satisfying Additivity, Dummy, Demand Monotonicity and Cross Monotonicity. The last says that when outputs i and j are cost complements (resp-cost substitutes) the cost share of i is non decreasing (resp-non increasing) in the demand of j. Two prominent methods in the class are the Shapley-Shubik method (i.e. the Shapley value of the Stand Alone cost game) and serial cost sharing (which extends to multiple goods a formula due to Moulin and Shenker). They are characterized respectively by a lower bound and by an upper bound on individual cost shares.     

Cost‐Based Anti‐dumping as a Repeated Game

In this paper, we consider anti‐dumping (AD) duties as a tool to facilitate collusion between a domestic and a foreign firm in an infinitely repeated differentiated Bertrand game, where prices are publicly observable and each firm receives a privately observed i.i.d. cost shock in each period. We consider second‐best scenarios, where market‐share or production arrangement with sidepayments is not allowed. We show that there exist equilibrium‐path reciprocal ADs. The collusive (trigger) price is distorted downward compared with complete information benchmark as a trade‐off between diminishing the incentive to deviate and ensuring off‐schedule deviation gains when private cost shocks are highly favourable. The model differs from Green and Porter ( 1984 ) and Rotemberg and Saloner ( 1986 ) in that it is the private cost shocks as opposed to public demand shocks that necessitate modifications of collusion. In conclusion, AD policy may encourage collusion, and therefore, unless the source of market imperfection is carefully examined, laissez faire might be a better choice.     

Commons with increasing marginal costs: random priority versus average cost*

Indivisible units are produced with increasing marginal costs. Under average cost, each user pays average cost. Under random priority, users are randomly ordered (without bias) and successively offered to buy at the true marginal cost. Both average cost (AC) and random priority (RP) inefficiently overproduce. RP tends to overproduce less, but which game collects more surplus depends much on the demand configuration. We show that a key to compare the welfare properties of the two mechanisms is the crowding factor, i.e., the number of potential users over the number of units of output users can afford: The more crowded the commons, the more RP outperforms AC. In the quadratic cost case, beyond the threshold value of 2.4 for the crowding factor, RP strongly outperforms AC; beneath it AC only mildly outperforms RP. Thus the RP mechanism manages crowded commons better than AC.     

A characterization of optimistic weighted Shapley rules in minimum cost spanning tree problems

In this paper we present an axiomatic characterization of the weighted Shapley value of the optimistic TU game associated with a minimum cost spanning tree problem. This characterization is based on two monotonicity properties, population monotonicity (if a new agent joint the society nobody is worse off) and the strong cost monotonicity (if the connection cost between any pair of agents increases nobody is better off), and weighted share of extra costs (the extra costs should be divided proportionally to the weights of the agents).      

“Constitutionalizing” the corporation

To become effective instruments in the attainment of a sustainable society, corporations should have their constitutional status settled. Thus far, mainly by Supreme Court decisions, corporations have an uncertain status. They are “persons” under the Constitution and have certain rights; but unlike natural persons, they do not have concomitant constitutional duties. Corporations should be viewed as “private” governments exercising substantial power in society. They are, however, considered to be associations of individuals rather than divisions of society. The need is to legitimate their governing power by “constitutionalizing” them. That can be done by corporations accepting, or having imposed upon them, two principal constitutional duties. First, means should be developed whereby corporate officers routinely take the general good into account. That duty could be implemented by making “social impact statements,” analogous to but broader than the familiar environmental impact statements, before making important corporate decisions. Secondly, as “sociological communities,” corporate officers wield considerable power over members of those communities. A bill of rights similar to the Constitution's Bill of Rights is recommended so as to make corporate power that is necessary for achievement of societal goals as tolerable and decent as possible. Acceptance of those duties would make corporations parts of, not separate from, the greater corporation called society. They would be private, profit-making entities with a definite public function. Preferably, the duties should be voluntarily accepted. Congress, however, has undoubted constitutional power to impose both, should it so desire.     

Noncooperative Equilibrium and Chamberlinian Monopolistic Competition

This paper addresses the existence of equilibrium for a nonatomic Bertrand game in a Chamberlinian environment. We reformulate O. Hart′s model (Rev. Econ. Stud. 52, 1985, 529–546) as a nonatomic game and show that under dispersion of tastes and continuity of the tastes density, there exists a pure-strategies ε-equilibrium where prices exceed marginal cost. Unlike Hart′s model there is no need to impose uniformity (or even independence) on the distribution of the m-tuple of differential commodities that consumers care about. Moreover, demand curves are allowed to vary across firms and in equilibrium firms may earn profits. Journal of Economic Literature Classification Numbers: B21, D43, L13.     

The price of anarchy of serial, average and incremental cost sharing

We compute the price of anarchy (PoA) of three familiar demand games, i.e., the smallest ratio of the equilibrium to efficient surplus, over all convex preferences quasi-linear in money. For any convex cost, the PoA is at least in the average and serial games, where n is the number of users. It is zero in the incremental game for piecewise linear cost functions. With quadratic costs, the PoA of the serial game is , and for the average and incremental games. This generalizes if the marginal cost is convex or concave, and its elasticity is bounded.      

Infinite horizon common interest games with perfect information

We consider infinite horizon common interest games with perfect information. A game is a K-coordination game if each player can decrease other players' payoffs by at most K times his own cost of punishment. The number K represents the degree of commonality of payoffs among the players. The smaller K is, the more interest the players share. A K-coordination game tapers off if the greatest payoff variation conditional on the first t periods of an efficient history converges to 0 at a rate faster than K^−t as t→∞. We show that every subgame perfect equilibrium outcome is efficient in any tapering-off game with perfect information. Applications include asynchronously repeated games, repeated games of extensive form games, asymptotically finite horizon games, and asymptotically pure coordination games.     

Endogenous timing,strategic tariff game and bilateral trade in vertical oligopoly

This paper builds an observable delay game in endogenous timing to study the possible occurrence of trade wars in a vertical, bilateral trade model. It examines the effects of production cost differences and order of moves on optimal tariffs, market equilibria, dumping margin and social welfare in both fixed timing and endogenous timing games. In a fixed timing game, it shows that price dumping in the intermediate good market arises from differences in country-specific final good production costs. Different from Bernhofen (1995; Journal of International Economics), trade costs resulting from reciprocal tariffs in upstream markets can reverse the price dumping under certain conditions. In an endogenous timing game, this paper finds that the magnitude of cost differences significantly influences countries’ decisions on the order of moves in a strategic tariff-making game. Both countries want to be the first movers under a small cost difference and consequently reach a simultaneous equilibrium result. This demonstrates that the second-best equilibrium proceeds under certain conditions. Under a large cost difference, sequential policy-making is the subgame perfect Nash equilibrium. If the cost difference is sufficiently large, both countries have an incentive to launch a trade war as a multiple equilibrium game.     

Reciprocity and Giving in a Consecutive Three‐Person Dictator Game with Social Interaction

We study pure indirect reciprocity by setting up a modified dictator game with three players A, B, and C acting sequentially. Subject A takes a share of a pie and passes the rest to subject B, while B divides the rest between herself and C. We find that this consecutive three‐person dictator game increases generosity compared with the traditional two‐person dictator game. We analyze the influence of social interaction and uncertainty. In treatments with certainty we observe pure indirect reciprocity: B indirectly reciprocates for A's behavior in the decision on how generous to be to C.     

On the voluntary provision of “weakest‐link” public goods: The case of private information

We characterize equilibria in a private‐provision public‐good game where individuals are allowed arbitrary contribution levels and the level of the public good equals the least contribution made by an individual. Equilibrium comparative statics are derived for the interim Pareto‐dominant equilibrium. First, improvements in the cost distribution of even only one player benefit all. Second, even with such “weakest‐link” public goods, for which greater similarity of preferences would seem to facilitate coordination, decreased heterogeneity can actually decrease payoffs. Indeed, increasing the riskiness of cost distributions has an ambiguous effect on welfare. Two mechanisms are provided for improving equilibrium payoffs: Technology transfer and cheap‐talk communication. While substantial welfare gains are possible, examples show that (a) technology transfer may be futile if a “regularity” condition is not satisfied and (b) cheap talk may be useless if the language for communication is not sufficiently rich.     

THE ASYMMETRIC IMPACT OF “INFORMATIVE” AND “UNINFORMATIVE” FEDERAL OPEN MARKET COMMITTEE STATEMENTS ON ASSET PRICES

This paper examines the effect of the information content of Federal Open Market Committee (FOMC) statements on the level and volatility of Treasuries and stock returns. Statements are separated into “informative” and “uninformative” groups with informative statements delivering important information which was not previously anticipated by the consensus. We find evidence that the information content of FOMC statements tends to generate an asymmetric response, with informative statements having a larger effect than uninformative statements. Asymmetries tend to be more pronounced for the conditional mean than conditional volatility. The behavior of volatility is tent‐shaped, spiking during policy announcements and declining before and after the release. We also find that the evolution of the language of the FOMC statements does matter to market participants and that joint releases of target rate changes and informative statements have a distinctly more pronounced impact than other types of announcements. (JEL E52, E58, E65, G12, G14)     

Economies with Land—A Game Theoretical Approach

With an economy with land (an economy of Debreu-type in which land is the unique commodity) we associate a cooperative game with transferable utility v . The set of all TU-games of type v is investigated and the set of equilibrium payoffs (in the TU-sense) of the economy is described as a subset of the core of v . We prove that equilibrium payoffs can be extended to population monotonic allocation schemes in the sense of Sprumont.     

PREFERENTIAL TRADE AGREEMENTS AND MULTILATERAL TARIFF COOPERATION*

Are preferential trade agreements (PTAs) building or stumbling blocks for multilateral trade liberalization? I address this question in an infinitely repeated tariff game between three countries engaged in intraindustry trade under oligopoly. The central result is that when countries are symmetric, a free trade agreement (FTA) undermines multilateral tariff cooperation by adversely affecting the cooperation incentive of the nonmember whereas a customs union (CU) does so via its effect on the cooperation incentives of members. However, when countries are asymmetric with respect to either market size or cost, there exist circumstances where PTAs facilitate multilateral tariff cooperation.     

The social cost problem,rights, and the (non)empty core

We revisit the “Coase theorem” through the lens of a cooperative game model which takes into account the assignment of rights among agents involved in a problem of social cost. We consider the case where one polluter interacts with many potential victims. Given an assignment or a mapping of rights, we represent a social cost problem by a cooperative game. A solution consists in a payoff vector. We introduce three properties for a mapping of rights. First, core compatibility indicates that the core of the associated cooperative games is nonempty. Second, Kaldor‐Hicks core compatibility indicates that there is a payoff vector in the core where victims are fully compensated for the damage once the negotiations are completed. Third, no veto power for a victim says that no victim has the power to veto an agreement signed by the rest of the society. We then demonstrate two main results. First, core compatibility is satisfied if and only if the rights are assigned either to the polluter or to the entire set of victims. Second, there is no mapping of rights satisfying Kaldor‐Hicks core compatibility and no veto power for a victim.     

OWN‐ AND CROSS‐PRICE ELASTICITIES FOR GAMES WITHIN A STATE LOTTERY PORTFOLIO

Lotto demand modeling typically focuses on a single game and evaluates whether estimated “effective price” (expected loss from buying one ticket) elasticity is consistent with net revenue maximization. However, a portfolio of several different lottery games is now usually offered to players and judging the effectiveness of agencies in generating revenue requires estimation of both cross‐price and own‐price elasticities. Here we employ data from Spain to derive elasticities. Results imply that games are under‐priced if net revenue maximization is the goal. But the cross‐price estimates suggest that the operator is successful in limiting the extent to which a large jackpot on one game cannibalizes same‐week sales of other games. The paper also analyzes the impacts from two increases in the level of entry fees introduced during the data period. These appear to have affected net revenue favorably. (JEL D12, G11, H27, H30, L83)     

A game of timing and visibility

We consider the following abstraction of competing publications. There are n players in the game. Each player i chooses a point x_i in the interval [0,1], and a player's payoff is the distance from its point x_i to the next larger point, or to 1 if x_i is the largest. For this game, we give a complete characterization of the Nash equilibrium for the two-player game, and, more important, we give an efficient approximation algorithm to compute numerically the symmetric Nash equilibrium for the n-player game. The approximation is computed via a discrete version of the game. In both cases, we show that the (symmetric) equilibrium is unique. Our algorithmic approach to the n-player game is non-standard in that it does not involve solving a system of differential equations. We believe that our techniques can be useful in the analysis of other timing games.     

THE GREAT RECESSION, “RAINY DAY” FUNDS,AND COUNTERCYCLICAL FISCAL POLICY IN LATIN AMERICA

We examine the fiscal policy options that were available to Latin American countries at the onset of the current global economic crisis, concluding that most of the major countries in the region possessed the fiscal space (as measured by credible fiscal sustainability and debt headroom) to run prudent countercyclical fiscal deficits. For those countries, the appropriate policy response involved a constrained fiscal expansion focused on productive public spending and financed by drawing on the “rainy day” funds—in the form of large stocks of foreign exchange reserves—that they accumulated in prior years, rather than by market borrowing. (JEL E62, E63, F34)     

Comment on “σ: The long and short of it”

I comment on some of the issues discussed by Robert Chirinko (Chirinko, R.S., 2008. σ: The long and short of it. Journal of Macroeconomics 30 (2), 671-686). I also offer some additional evidence and discuss the theoretical implications of the empirical findings regarding σ.