a median voter model of social security this paper presents a theoretical median voter analysis of the determination of the level of social security the framework for the analysis is a continuous time overlapping generations model with nonaltruistic households facing borrowing constraints in the capital market a majority voting equilibrium is shown to exist in which the median voter is liquidity constrained the desired level of social security for each voter is a declining function of the preexisting level of social security as a consequence in a sequence of votes on social security beginning with a zero level the program initially overshoots its steady state value copyright 1989 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

the principal agent relationship with an informed principal ii common values in many circumstances a principal may have relevant private information when she proposes a contract to an agent we analyze such a principal agent relationship as a noncooperative game the principal proposes a contract which is accepted or rejected by the agent who for most of our analysis has no private information the contract is executed if accepted otherwise the reservation allocation takes effect this allocation may be determined by a pre existing contract which the principal by her proposal is attempting to renegotiate or it may simply be the no trade point in this paper we assume that the principal s information directly affects the agent s payoff before solving the game we discuss pareto efficiency with asymmetric information we define an incentive compatible allocation to be weakly interim efficient wie if there exists no alternative incentive compatible allocation that both parties prefer for all possible beliefs that the agent might have about the principal s private information type we show that any wie allocation is interim efficient ie for some beliefs the rothschild stiglitz wilson rsw allocation relative to the reservation allocation l is the allocation that maximizes the payoff of each type of principal within the class of incentive compatible allocations that guarantee the agent at least the utility he gets from a irrespective of his beliefs about the principal s type the equilibrium set of the contract proposal game consists of the allocations that weakly pareto dominate the rsw allocation thus there is a unique equilibrium outcome if and only if the latter is ie and the equilibrium outcome is the rsw allocation itself after characterizing the equilibrium allocations we study those that are renegotiation proof when either the principal or the agent leads the renegotiation we then compare our contract proposal game which is a signaling model with its screening counterpart we conclude by extending our results to the case in which the agent as well as the principal has private information under the assumption of quasi linear preferences

on the role of confidentiality and deadlines in bilateral negotiations abstract the preference between public and private negotiations for a buyer who sequentially visits two sellers is examined it is shown that the buyer weakly prefers private negotiations so as to create strategic uncertainty about the trade history with substitute goods such uncertainty is valuable only when price offers have short deadlines that prevent a head to head competition with complementary goods strategic uncertainty is valuable to the extent that price coordination becomes a concern for sellers which is likely to be the case when sellers possess high bargaining powers their price offers have short deadlines and or goods are weak complements sellers strategic deadline choices as well as their incentives to disclose information about negotiations are also investigated

the principal agent relationship with an informed principal the case of private values we analyze the principal agent relationship when the principal has private information as a three stage noncooperative game contract proposal acceptance refusal and contract execution we assume that the information does not directly affect the agent s payoff private values equilibrium exists and is generically locally unique moreover it is pareto optimal for the different types of principal the principal generically does strictly better than when the agent knows her information equilibrium allocations are the walrasian equilibria of an economy where the traders are different types of principal and exchange the slack on the agent s individual rationality and incentive compatibility constraints

optional fixed fees in multilateral vertical relations abstract we examine vertical contracting in a perfect information environment in contrast to mcafee and schwartz mcafee r p schwartz m 1994 opportunism in multilateral vertical contracting nondiscrimination exclusivity and uniformity american economic review vol 84 pp 210 230 we demonstrate that outcomes are efficient if an upstream monopolist has the choice of requiring upfront fixed fee payments or making them optional

trading in networks theory and experiments intermediation is a prominent feature of economic production and exchange two features of intermediation are salient coordination among traders between the source and the destination and competition between alternative combinations of intermediaries we develop a simple model to study these forces and we test the theoretical predictions in experiments our theoretical analysis yields a complete characterization of pricing equilibrium in networks there exist both ecient and inecient equilibria suggesting a key role of coordination among intermediaries strategic interaction leads to either buyer and seller retaining all surplus or intermediaries extracting all surplus we develop conditions on network structure under which these di erent extremal outcomes arise respectively laboratory experiments show that eciency prevails in almost all cases so traders are successful in coordination subjects coordinate on extreme surplus division finally experiments highlight the role of network structure in determining pricing and the

voting on pensions a survey abstract the paper presents a nonexhaustive survey of the literature designed to explain emergence size and political sustainability of pay as you go pension systems it proposes a simple framework of analysis a small open two overlapping generation economy model around which some variants are displayed dictatorship of the median voter is assumed the text is organized to answer the following questions i do political equilibria with payg pension schemes exist ii why do they emerge iii what are the conditions for the participation constraint of the pension game to be verified and finally iv what is the size of the pension system chosen by the median voter and how is this size influenced by an exogenous e g demographic shock

internal rationality imperfect market knowledge and asset prices we present a decision theoretic framework in which agents are learning about market behavior and that provides microfoundations for models of adaptive learning agents are internally rational i e maximize discounted expected utility under uncertainty given dynamically consistent subjective beliefs about the future but agents may not be externally rational i e may not know the true stochastic process for payoff relevant variables beyond their control this includes future market outcomes and fundamentals we apply this approach to a simple asset pricing model and show that the equilibrium stock price is then determined by investors expectations of the price and dividend in the next period rather than by expectations of the discounted sum of dividends as a result learning about price behavior affects market outcomes while learning about the discounted sum of dividends is irrelevant for equilibrium prices stock prices equal the discounted sum of dividends only after making very strong assumptions about agents market knowledge

controlling opportunism in vertical contracting when production precedes sales in a make to stock vertical contracting setting with private contracts when retailers do not observe each other s stocks before choosing their prices an opportunism problem always exist in contract equilibria but public market wide resale price maintenance rpm can restore monopoly power however other widely used tools which do not fall under antitrust scrutiny and require only private bilateral contracts such as buyback contracts also allow the producer to fully exercise his monopoly power we conclude that a more lenient policy toward rpm is unlikely to affect the producer s ability to control opportunism

contracting with externalities the paper studies inefficiencies arising in contracting between one principal and n agents when the utility of each agent depends on all agents trades with the principal when the principal commits to a set of publicly observable bilateral contract offers the arising inefficiency is due entirely to the externalities imposed on non signers in contrast when the principal s offers are privately observed the distortion is due to the externalities given agents equilibrium trades comparison of the two externalities determines the relative efficiency of the two contracting regimes in both cases we show that when n is large each agent can be treated as non pivotal provided that appropriate continuity assumptions are satisfied we also study the case in which the principal can condition each agent s trade on other agents messages we characterize the set of such mechanisms in which each agent s participation is voluntary when the principal can commit to any such mechanism she implements the first best outcome while threatening each deviator with the harshest possible punishment however in the presence of noise that goes to zero slower than n goes to infinity in the limit we obtain a generally inefficient outcome in which each agent feels non pivotal

vertical contracting with informational opportunism we consider vertical contracting arrangements between a manufacturer and a retailing network when retailers have private information and the organization is run through bilateral contracts we highlight a new form of informational opportunism arising when the manufacturer manipulates information learned separately in each relationship we characterize the set of allocations robust to such opportunism by means of simple ex post incentive compatibility constraints those constraints limit the manufacturer s ability to use yardstick competition among retailers they simplify contracts and restore a rent efficiency trade off even with correlated information we show that sell out contracts are optimal under a wide range of circumstances

the revelation and delegation principles in common agency games in the context of common agency adverse selection games we illustrate that the revelation principle cannot be applied to study equilibria of the multi principal games we then demonstrate that an extension of the taxation principle what we term the delegation principle can be used to characterize the set of all common agency equilibria this abstract was borrowed from another version of this item

coordination and bargaining power in contracting with externalities abstract building on genicot and ray g genicot d ray contracts and externalities how things fall apart j econ theory 131 2006 71 100 we develop a model of non cooperative bargaining that combines the two main approaches in the literature of contracting with externalities the offer game in which the principal makes simultaneous offers to the agents and the bidding game in which the agents make simultaneous offers to the principal allowing for agent coordination we show that the outcome of our bargaining procedure may differ remarkably from those of the offer and the bidding games in particular we find that bargaining can break agents coordination and that the principal s payoff can be decreasing in his own bargaining power

non exclusive competition in the market for lemons in order to check the impact of the exclusivity regime on equilibrium allocations we set up a simple akerlof like model in which buyers may use arbitrary taris under exclusivity we obtain the zero profit separating riley rothschilds stiglitz allocation under non exclusivity there is also a unique equilibrium allocation that involves a unique price as in akerlof 1970 these results can be applied to insurance in the dual model in yaari 1987 and have consequences for empirical tests of the existence of asymmetric information

robust predictions for bilateral contracting with externalities the paper studies bilateral contracting between one principal and n agents when each agent s utility depends on the principal s unobservable contracts with other agents we show that allowing deviations to menu contracts from which the principal chooses bounds equilibrium outcomes in a wide class of bilateral contracting games without imposing ad hoc restrictions on the agents beliefs this bound yields for example competitive convergence as n in environments in which an appropriately defined notion of competitive equilibrium exists we also examine the additional restrictions arising in two common bilateral contracting games the offer game in which the principal makes simultaneous offers to the agents and the bidding game in which the agents make simultaneous offers to the principal

competition in loan contracts we present a model of an unsecured loan market many lenders simultaneously offer loan contracts a debt level and an interest rate to a borrower the borrower may accept more than one contract her payoff if she defaults increases in the total amount borrowed if this payoff is high enough deterministic zero profit equilibria cannot be sustained lenders earn a positive profit and may even charge the monopoly price the positive profit equilibria are robust to increases in the number of lenders despite the absence of asymmetric information the competitive outcome does not obtain in the limit

how strong are weak patents economists usually conceive of patents as property rights that prevent others from practicing the patenting technology unless they first obtain a license from the patent holder even for ironclad patents i e for patents that are certain to be valid the existing literature has shown that the analysis of equilibrium licensing contracts is surprising subtle and complex 1 for example the analysis is quite different depending upon whether one firm s licensing contract is observable to the other firms likewise equilibrium outcomes are quite different if royalties must be linear than in the case where two part tariffs and other non linear royalties are permitted in that literature a downstream firm that refuses to sign a contract with the upstream supplier either exits the industry in the case that the upstream supplier controls an essential input or must rely on more costly inputs in the case of a non essential input in other words the downstream firm s threat point is to use some backstop technology in practice however patents are issued after a brief examination by the patent office to see if they meet the statutory requirements for novelty and non obviousness mounting evidence indicates that many weak patents i e patents unlikely to be found valid if challenged in court are issued by the u s patent and trademark office uspto 2 some observers view this with great alarm arguing that uspto is handing out undeserved monopolies others by contrast have suggested that these weak patents are of little concern because they will have little commercial impact because they will be licensed at commensurately low royalty rates or not enforced at all we study the commercial impact of weak patents more precisely we define a patent s strength as the probability that it will be found valid if challenged in court and we examine the relationship between a patent s strength and the royalties that it can command the distinctive

opportunism in multilateral vertical contracting nondiscrimination exclusivity and uniformity comment an input supplier selling to competing downstream firms would benefit from publicly committing at the outset to all contracts efficient commitment however would require complete contracts the authors study instead bilateral contracting without commitment regarding others terms each firm then fears that the supplier might opportunistically renegotiate another s contract to increase bilateral profit at the firm s expense the authors show that nondiscrimination clauses generally cannot curb such third party opportunism even with symmetric firms to reassure firms crude forms of commitment may be adopted this could explain the pervasiveness of exclusivity arrangements and the striking uniformity and intertemporal rigidity of franchise contracts copyright 1994 by american economic association

public pensions as optimal social contracts abstract a simple overlapping generations model is modified to allow for an externality experienced by the young from consumption by the elderly this sets up a game between generations in which one generation s strategy may be to save too little and rely on gifts from the young e g public assistance for retirement income social security can therefore be viewed as a pareto optimal contract to restore efficient intertemporal allocation a funded public pension plan corresponds to forced saving but is vulnerable in that the next young generation may stop contributing rely on its children for retirement assistance and meanwhile reap the consumption externality from the current elderly s social security benefits this suggests a forced giving or pay as you go type of compulsory pension plan such as exists in most nations which also has the advantage of aiding the initial old generation and therefore generating an immediate consumption externality for the initial young the approach can also be used to explain other aspects of existing social security

constraints in perfect foresight models the case of old age savings and public pensions abstract the solution of discrete time perfect foresight models with constrained state variables differs considerably from the solution of models without constraints in this paper this is worked out for a simple model of decision making on public pensions

expectations on pension schemes under non stationary conditions abstract the way expectations are treated in models concerning pension schemes in generally decisive for their predicted development in this letter we show how these expectations can consistently be modeled in a dynamic context without having to rely on adhoc assumptions

the welfare effects of upstream mergers in the presence of downstream entry barriers we examine the incentives for upstream firms to consolidate horizontally and the impact of this process on industry performance when there are downstream entry barriers and firms negotiate bilaterally in the short run consumers are not worse off with upstream mergers since consolidation only results in a redistribution of industry rents in the long run consumers are better off after upstream mergers since they induce more entry into that segment when social welfare is evaluated a limit on upstream consolidation may prevent excessive entry but upstream entry can be sometimes insufficient if the retailers intrinsic bargaining power is excessive

social security as trade among living generations we model u s social security that is legislated endogeneously by living generations specifically we consider the effects of social security on resource allocation and pareto optimality examining which generations gain from social security and whether some generations lose because saving and transfer decisions are made sequentially in the real world we use an infinite horizon overlapping generations framework in which life cycle saving and transfers to the old are determined by living agents we focus on the case in which agents are altruistic but place sufficiently greater weight on own comsumption than on the consumption of agents in other generations so that starting from a steady state without social security living agents would gain utility if consumption were shifted marginally to them from later generations excerpt

endogenous games and mechanisms side payments among players we characterize the outcomes of games when players may make binding offers of strategy contingent side payments before the game is played this does not always lead to efficient outcomes despite complete information and costless contracting the characterizations are illustrated in a series of examples including voluntary contribution public good games cournot and bertrand oligopoly principal agent problems and commons games among others

buyer power and intrabrand coordination we analyze the competitive effects of vertical contracts in a contracting situation where rival retailers offer contracts to a manufacturer in contrast to bernheim and whinston 1998 who study the situation in which competing manufacturers offer contracts to a common retailer we find that two part tariffs even if contingent on exclusivity or not do not suffice to implement the monopolyoutcome richer arrangements including e g conditional fixed fees and upfront payments are thus required to internalize all contracting externalities the welfare implications are ambiguous on the one hand richer contracts ensure that no efficient retailer is excluded on the other hand they allow firms to maintain monopoly prices despite intrabrand competition simulations suggest that the latter effect may be more significant