wealth wages and wedlock explaining the college gender gap reversal we study the role of changes in the wage structure and expectations about marriage in explaining the college gender gap reversal with strongly diminishing marginal utility of wealth and in the presence of a gender wage gap single women have a greater incentive than single men to invest in education marriage market distortions tend to depress the overall benefit of education for women relative to men we parameterize the model using us census data for the cohort born in 1950 and show that it can generate a reversal the most important driving force is the decline in marriage rates this article is protected by copyright all rights reserved

communication in repeated games with private monitoring abstract the paper considers repeated games where each player can be observed by only a subset of the other players and where players can make public announcements about the behavior of the players they observed we address the following question what is the minimal level of observability that is required to obtain efficient outcomes the main result is that the limit set of sequential equilibrium payoffs when the discount factor tends to one contains the set of individual rational payoffs whenever each player is observed by at leasttwoother players journal of economic literatureclassification number c73

competition and price variation when consumers are loss averse we modify the salop 1979 model of price competition with differentiated products by assuming that consumers are loss averse relative to a reference point given by their recent expectations about the purchase consumers sensitivity to losses in money increases the price responsiveness of demand and hence the intensity of competition at higher relative to lower market prices reducing or eliminating price variation both within and between products when firms face common stochastic costs in any symmetric equilibrium the markup is strictly decreasing in cost even when firms face different cost distributions we identify conditions under which a focal price equilibrium where firms always charge the same focal price exists and conditions under which any equilibrium is focal

the benefits and costs of strong patent protection a contribution to the current debate abstract today s conventional wisdom is that strong patent rights are conducive to economic progress yet not long ago students of the patent system took a more nuanced position arguing that often strong patents were not necessary to induce invention and entailed significant economic costs several empirical studies have supported this position however the current advocacy invokes theories of the positive benefits of patents that were repressed in the earlier more negative analyses this essay reviews these theories and the empirical evidence that might bear on them the authors conclude that there is reason for concern that the present movement towards stronger patent protection may hinder rather than stimulate technological and economic progress

collusion and price rigidity we consider an in nitely repeated bertrand game in which prices are publicly observed and each rm receives a privately observed i i d cost shock in each period we focus on symmetric perfect public equilibria sppe wherein any punishments are borne equally by all rms we identify a tradeoff that is associated with collusive pricing schemes in which the price to be charged by each rm is strictly increasing in its cost level such fully sorting schemes offer efficiency bene ts as they ensure that the lowest cost rm makes the current sale but they also imply an informational cost distorted pricing and or equilibrium path price wars since a higher cost rm must be deterred from mimicking a lower cost rm by charging a lower price a rigid pricing scheme where a rm s collusive price is independent of its current cost position sacri ces efficiency bene ts but also diminishes the informational cost for a wide range of settings the optimal symmetric collusive scheme requires i the absence of equilibrium path price wars and ii a rigid price if rms are sufficiently impatient however the rigid pricing scheme cannot be enforced and the collusive price of lower cost rms may be distorted downward in order to diminish the incentive to cheat when the model is modi ed to include i i d public demand shocks the downward pricing distortion that accompanies a rm s lower cost realization may occur only when current demand is high

efficient patent pools the paper builds a tractable model of patent pools agreements among patent owners to license sets of their patents it provides a necessary and sufficient condition for patent pools to enhance welfare and shows that requiring pool members to be able to independently license patents matters if and only if the pool is otherwise welfare reducing the paper allows patents to differ in importance asymmetric blocking patterns and licensors to also be licensees we undertake some initial exploration of the impact of pools on innovation the analysis has broader applicability than pools being relevant to a number of co marketing arrangements

optimal cartel pricing in the presence of an antitrust authority the dynamic behavior of a price fixing cartel is explored when it is concerned about creating suspicions that a cartel has formed consistent with preceding static theories the cartel s steady state price is decreasing in the damage multiple and the probability of detection however contrary to those theories it is independent of the level of fixed fines it is also shown that the cartel prices higher when a more competitive benchmark price is used in calculating damages

filing behaviour regarding essential patents in industry standards abstract this article addresses companies filing behaviour in respect of patents relevant for standard setting essential patents we discuss applicants incentives to achieve conformity of patent applications with technology standards under development based on these incentive structures we hypothesise that the claims of essential patents are amended more often than those of comparable patents additionally we argue that applicants have incentives to delay the grant decision as a result essential patents are hypothesised to have longer pendency times than comparable patents this implies more possibilities for applicants to exploit the flexibility within the patent application process to amend the claims of pending patent applications for empiric validation we use procedural patent data from the european patent application process we adopt a one to one matching approach pairing essential patents in telecommunications with control patents on the matching criteria of technology class filing date and applicant name additionally we compare these essentials with patents from companies that do not hold standards relevant patents we detect higher numbers of claims and amendments to claims as well as other relevant characteristics for the essential patents using survival analysis we show that the higher numbers of amendments and claims and the higher share of x references are responsible for higher pendency times since they significantly decrease hazard rates in the survival analysis we discuss the general implications for the functioning of the patent system and address the detrimental effects caused by the high degree of uncertainty generated by these filing strategies possible solutions such as better co ordination are devised

optimal cartel trigger price strategies abstract a dynamical model of industry equilibrium is described in which a cartel deters deviations from collusive output levels by threatening to produce at cournot quantities for a period of fixed duration whenever the market price falls below some trigger price in this model firms can observe only their own production level and a common market price the market demand curve is assumed to have a stochastic component so that an unexpectedly low price may signal either deviations from collusive output levels or a downward demand shock

the initiation and withdrawal of odd eighth quotes among nasdaq stocks an empirical analysis christie and schultz 1994 journal of finance 49 1813 1840 nd that market makers in many active nasdaq stocks avoid odd eighth quotes this paper studies 67 58 nasdaq stocks whose market makers initiate withdraw odd eighth quotes these regime shifts are often completed within the span of a day and coincide with dramatic changes in dollar percentage and e ective spreads in most cases we are unable to identify comparable changes in the costs of making markets we do identify long run changes in average prices that may provide a partial explanation however we also nd

business cycles and monetary regimes in emerging economies a role for a monopolistic banking sector abstract this study shows that the presence of imperfect competition in the banking system propagates external shocks and amplifies the business cycle strategic limit pricing aimed at protecting retail niches from potential competitors generates countercyclical bank markups markup increments during recessions directly increase borrowing costs for firms and indirectly damage the financial position of firms balance sheets increasing the risk perception of lenders i use bayesian techniques and data from argentina to show that the inclusion of monopolistic banking improves the fit of the new keynesian small open economy model

the folk theorem with imperfect public information the authors study repeated games in which players observe a public outcome that imperfectly signals the actions played they provide conditions guaranteeing that any feasible individually rational payoff vector of the stage game can arise as a perfect equilibrium of the repeated game with sufficiently little discounting the central condition requires that there exist action profiles with the property that for any two players no two deviations one by either player give rise to the same probability distribution over public outcomes the results apply to principal agent partnership oligopoly and mechanism design models and to one shot games with transferable utilities copyright 1994 by the econometric society

a theory of dynamic oligopoly ii price competition kinked demand curves and edgeworth cycles we provide game theoretic foundations for the classic kinked demand curve equilibrium and edgeworth cycle we analyze a model in which firms take turns choosing prices the model is intended to capture the idea of reactions based on short run commitment in a markov perfect equilibrium mpe a firm s move in any period depends only on the other firm s current price there are multiple mpe s consisting of both kinked demand curve equilibria and edgeworth cycles in any mpe profit is bounded away from the bertrand equilibrium level we show that a kinked demand curve at the monopoly price is the unique symmetric renegotiation proof equilibrium when there is little discounting we then endogenize the timing by allowing firms to move at any time subject to short run commitments we find that firms end up alternating thus vindicating the ad hoc timing assumption of our simpler model we also discuss how the model can be enriched to provide explanations for excess capacity and market sharing keiiwords tacit collusion markov perfect equilibrium kinked demand curve edgeworth cycle excess capacity market sharing endogenous timing

emerging ways to address the reemerging conflict between patenting and technological standardization the relationship between standards and intellectual property rights iprs is a complementary but troubled one the way it is managed affects the way stakeholders contribute to standards and may ultimately affect the way some technologies and even industries evolve a spate of recent legal controversies has been accompanied by the emergence of new mechanisms to help govern the risk of conflict here this article provides an empirical analysis of these attempts to reconcile the aims of these regimes

communication in repeated games with imperfect private monitoring this paper examines repeated games in which each player observes a private and imperfect signal on the actions played and in which players are allowed to communicate using public messages providing incentives for players to reveal their observations generates revelation constraints that combined with signal imperfections may be a source of inefficiencies however by delaying the revelation of their observations players may economize on the cost of deterring deviations and thereby avoid these inefficiencies because a player would not want to trigger a sanction that would penalize him too revelation constraints also tend to make sanctions difficult to enforce however with at least three players detecting deviations may not require that all the players reveal their observations in that case we obtain a nash threat version of the folk theorem with two players we do not obtain a similar result nevertheless we show that an efficient outcome can almost always be approximated

essential patents frand royalties and technological standards in this paper we abandon the usual assumption that patents bring known benefits to the industry or that their benefits are known to all parties when royalty payments are increasing in one s patent portfolio private information about the quality of patents leads to a variety of distortions in particular the incentives of firms to pad by contributing weak patents three main results that emerge from the analysis are that i the threat of court disputes reduces incentives to pad but at the cost of lower production of strong patents ii mitigating this undesirable side effect calls for a simultaneous increase in the cost of padding that is a better filtering of patent applications iii upstream firms have more incentives to pad than vertically integrated firms which internalize the fact that patent proliferation raises the share of profits going to the upstream segment of the industry but at the expense of its downstream segment this seems consistent with recent evidence concerning padding

motives to patent empirical evidence from germany abstract against the background of the patent upsurge we first analyse the role of patenting and alternative instruments to protect intellectual property based on a sample of german companies active in patenting in a second step we investigate the motives to patent considering sector and company size effects we find that company size matters both for the importance of instruments and the motives to patent especially important are the new strategic motives to patent like using patents to improve a company s own position in negotiations with partners licensees and the financial sector or to use patents as incentives for r d personnel or performance indicators these correlate positively with company size we derive some possible challenges for future patent policies from these insights

optimal cartel equilibria with imperfect monitoring abstract there exist optimal symmetric equilibria in the green porter model 4 8 having an elementary intertemporal structure such an equilibrium is described entirely by two subsets of price space and two quantities the only production levels used by firms in any contingency the central technique employed in the analysis is the reduction of the repeated game to a family of static games

cartel enforcement with uncertainty about costs what cartel agreements are possible when firms have private information about production costs in order for a cartel agreement to work it must take into account the incentives for firms to misrepresent their cost information and it must provide sufficient reward so that no firm wishes to defect for private cost uncertainty we characterize the set of cartel agreements with side payments that can be supported as bayesian nash equilibria we show that if defection results in either cournot or bertrand competition the incentive problems in large cartels are severe enough to prevent the cartel from achieving the monopoly outcome in contrast with common cost uncertainty the incentive problems become less severe in large cartels allowing perfect collusion

tacit collusion with imperfect monitoring in the canadian manufacturing industry an empirical study this article undertakes a cross sectoral analysis of a salient empirical implication of the model of tacit collusion advanced by abreu pearce and stachetti 1986 specifically we assess the prevalence of a first order markovian process for alternating between price wars and collusive periods through nonparametric tests the analysis focuses on 30 different industries in canada the evidence provides weak support for optimal collusion in one industry which is consistent with the idea that such kind of collusive arrangements is unusual or if collusion is all too common that price wars as deviations from collusion are rare

the rigidity of prices this paper uses evidence on individual transaction prices to analyze price behavior the evidence shows that for many transactions pricesremain rigid for periods exceeding one year the rigidity of price ispositively correlated with industry concentration for several productsthe correlation of price changes across buyers is low the paper alsoinvestigates the relationship between price rigidity price change andthe length of time a buyer and seller have been doing business together the author interprets the evidence as emphasizing the importance of nonprice rationing and the inadequacy of models in whichprice movements alone clear markets copyright 1986 by american economic association

collusion with persistent cost shocks we consider a dynamic bertrand game in which prices are publicly observed and each firm receives a privately observed cost shock in each period although cost shocks are independent across firms within a firm costs follow a first order markov process we analyze the set of collusive equilibria available to firms emphasizing the best collusive scheme for the firms at the start of the game in general there is a trade off between productive efficiency whereby the low cost firm serves the market in a given period and high prices we show that when costs are perfectly correlated over time within a firm if the distribution of costs is log concave and firms are sufficiently patient then the optimal collusive scheme entails price rigidity firms set the same price and share the market equally regardless of their respective costs when serial correlation of costs is imperfect partial productive efficiency is optimal for the case of two cost types first best collusion is possible if the firms are patient relative to the persistence of cost shocks but not otherwise we present numerical examples of first best collusive schemes

endogenous price commitment sticky and leadership pricing evidence from the italian petrol market this article studies dynamic pricing strategies in the italian gasoline market before and after the market leader unilaterally announced its commitment to adopt a sticky pricing policy using daily italian firm level prices and weekly average eu prices we show that the effect of the new policy was twofold first it facilitated price alignment and coordination on price changes after the policy change the observed pricing pattern shifted from cost based to sticky leadership pricing second using a dif in dif estimation and a synthetic control group we show that the causal effect of the new policy was to significantly increase prices through sticky leadership pricing our paper highlights the importance of price commitment by a large firm in order to sustain tacit collusion

collusion over the business cycle we present a theory of collusive pricing for markets in which demand alternates stochastically between fast growth boom and slow growth recession phases we show that 1 the most collusive prices are weakly procyclical countercyclical when demand growth rates are positively negatively correlated through time and 2 the amplitude of the collusive pricing cycle is larger when the expected duration of boom phases decreases and when the expected duration of recession phases increases we also offer a generalization of rotemberg and saloner s 1986 model interpreting their findings in terms of transitory demand shocks that occur within broader business cycle phases

repeated insurance contracts and moral hazard abstract an attempt is made to account for the frequently observed phenomenon of insurance companies offering discounts to clients who possess a favorable record of past claims we argue that such discounts provide a mechanism which enables both insurer and insured to counteract the inefficiency which arises from moral hazard

bertrand competition when rivals costs are unknown the conclusions of the bertrand model of competition are substantially altered by the presence of asymmetric information about rivals costs asymmetric information eliminates the discontinuity in the bertrand model and significantly alters the properties of the market equilibrium in the bertrand nash equilibrium when rivals costs are unknown firms price above marginal cost and have positive expected profit the analysis is extended to franchise competition the market equilibrium is sensitive to market structure and yields incentives for entry copyright 1995 by blackwell publishing ltd

the impact of cyclical demand movements on collusive behavior recent work by rotemberg and saloner 1986 investigates the effect of the business cycle on optimal collusive pricing by specifying that demand is subject to i i d shocks an implication of the i i d assumption is that firms expectations on future demand are unrelated to the current level of demand we put forth a model that allows for both the level of current demand and firms expectations on future demand to change over time thus it captures two important properties of the business cycle our analysis reveals that while the gain to deviating from a collusive agreement is greatest during booms firms find it most difficult to collude during recessions as the forgone profits from inducing a price war are relatively low an implication of this effect for pricing behavior is that at the same level of demand price is lower when demand is declining than when demand is rising consistent with previous theoretical work we find that firms price countercyclically for a range of values for the discount factor however numerical simulations reveal a greater tendency for firms to price countercyclically during recessions than during booms