efficient mechanisms for bilateral trading we consider bargaining problems between one buyer and one seller for a single object the seller s valuation and the buyer s valuation for the object are assumed to be independent random variables and each individual s valuation is unknown to the other we characterize the set of allocation mechanisms that are bayesian incentive compatible and individually rational and show the general impossibility of ex post efficient mechanisms without outside subsidies for a wide class of problems we show how to compute mechanisms that maximize expected total gains from trade and mechanisms that can maximize a broker s expected profit journal of economic literature classification number 026

hybrid r d we develop a model of r d collaboration in which individual firms carry out in house research on core activities and undertake bilateral joint projects on non core activities with other firms we develop conditions on the profit functions of the firm under which r d investments in different projects of a firm are complementary we show that this condition is met by standard price and quantity setting oligopoly models we then study the relation between the number of joint projects and investments and profits in this context we identify a second aspect of complementarity equilibrium investments in in house as well as in each joint project are increasing in the number of projects however we find that an increase in number of joint projects of all firms lowers collective profits suggesting the presence of excessive incentives for conducting research

the economic impact of social ties evidence from german reunification we use the fall of the berlin wall in 1989 to show that personal relationships which individuals maintain for noneconomic reasons can be an important determinant of regional economic growth we show that west german households who had social ties to east germany in 1989 experienced a persistent rise in their personal incomes after the fall of the berlin wall moreover the presence of these households significantly affects economic performance at the regional level it increases the returns to entrepreneurial activity the share of households who become entrepreneurs and the likelihood that firms based within a given west german region invest in east germany as a result west german regions that for idiosyncratic reasons have a high concentration of households with social ties to the east exhibit substantially higher growth in income per capita in the early 1990s a one standard deviation rise in the share of households with social ties to east germany in 1989 is associated with a 4 7 percentage point rise in income per capita over six years we interpret our findings as evidence of a causal link between social ties and regional economic

of networks and markets the rise and rise of a south indian town the example of tiruppur s cotton knitwear industry abstract tiruppur town is the center of a tightly clustered range of activities related to the cotton knitwear industry the successful and dramatic expansion which has taken place over the last 15 years has meant many more jobs limited technological improvement improved quality in yarn and fabric and an increasingly diverse range of garments for the larger firms in the industry access to export markets has been the driving force to improving their competitiveness wages remain low and working conditions poor however perhaps partly because capital concentration has not on the whole been accompanied by centralized vertically integrated production nevertheless clustering and dense interfirm networks provide advantages for firms of all sizes since process specialization is spatially divisible

interfirm relationships and informal credit in vietnam trading relations in vietnam s emerging private sector are shaped by two market frictions the difficulty of locating trading partners and the absence of legal enforcement of contracts examining relational contracting we find that a firm trusts its customer enough to offer credit when the customer finds it hard to locate an alternative supplier a longer duration of trading relationship is associated with larger credit as is prior information gathering customers identified through business networks receive more credit these network effects are enduring suggesting that networks are used to sanction defaulting customers

public goods in networks this paper considers incentives to provide goods that are non excludable along social or geographic links we find first that networks can lead to specialization in public good provision in every social network there is an equilibrium where some individuals contribute and others free ride in many networks this extreme is the only outcome second specialization can benefit society as a whole this outcome arises when contributors are linked collectively to many agents finally a new link increases access to public goods but reduces individual incentives to contribute hence overall welfare can be higher when there are holes in a network

incentive compatible and stable trade mechanisms on networks abstract we study a network of buyers and sellers where each seller owns an indivisible object and has no incentive to keep it while each buyer has a downward sloping demand curve which is private information only the connected buyer seller pairs can engage in trade we search for trade mechanisms that are efficient strategy proof bilateral trade stable and individually rational in general there does not exist a trade mechanism simultaneously satisfying these properties the tension between strategy proofness and bilateral trade stability is generated by the intersection between sets of competitors of a buyer at different sellers such intersections often allow the buyer to manipulate via demand reductions the prices paid in the network the observed tension can be resolved if and only if the underlying network is cycle free in such a case there is a unique trade mechanism which satisfies our four properties a generalized vickrey auction

bilateralism and free trade we study a setting with many countries in each country there are firms that can sell in the domestic as well as foreign markets countries can sign bilateral free trade agreements that lower import tariffs and thereby facilitate trade we allow a country to sign any number of bilateral free trade agreements a profile of free trade agreements defines the trading regime our principal finding is that in symmetric settings bilateralism is consistent with global free trade we also explore the effects of asymmetries across countries and political economy considerations on the incentives to form trade agreements

local matching of flexible load in smart grids abstract today s power systems are experiencing a transition from primarily fossil fuel based generation toward greater shares of renewable energy sources it becomes increasingly costly to manage the resulting uncertainty and variability in power system operations solely through flexible generation assets incorporating demand side flexibility through appropriately designed incentive structures can add an additional lever to balance demand and supply based on a supply model using empirical wind generation data and a discrete model of flexible demand with temporal constraints we design and evaluate a local online market mechanism for matching flexible load and uncertain supply under this mechanism truthful reporting of flexibility is a dominant strategy for consumers reducing payments and increasing the likelihood of allocation suppliers during periods of scarce supply benefit from elevated critical value payments as a result of flexibility induced competition on the demand side we find that for a wide range of the key parameters supply capacity flexibility level the cost of ensuring incentive compatibility in a smart grid market relative to the welfare optimal matching is relatively small this suggests that local matching of demand and supply can be organized in a decentral manner in the presence of a sufficiently flexible demand side extending the stylized demand model to include complementary demand structures we demonstrate that decentral matching induces only minor efficiency losses if demand is sufficiently flexible furthermore by accounting for physical grid limitations we show that flexibility and grid capacity exhibit complementary characteristics

networks of collaboration in oligopoly abstract in an oligopoly prior to competing in the market firms have an opportunity to form pair wise collaborative links with other firms these pair wise links involve a commitment of resources and lead to lower costs of production of the collaborating firms we study the incentives of firms to form links and the architecture of the resulting collaboration network we find that incentives to form links are intimately related to the nature of market competition our analysis also suggests that collaborations are used by firms to generate competitive advantage and that strategically stable networks are often asymmetric with some firms having many links while others have few links or are isolated specifically we show that networks with the dominant group architecture stars and inter linked stars are stable we also present some results on the architecture of socially efficient networks

market equilibrium under incomplete and imperfect information in bilateral electricity markets in contrast to the centralized pool model bilateral markets present a decision making situation in which information plays a major role along with the physical and operative constraints of the network we propose a model that includes network constraints for competitive bilateral electricity markets based on an evolutionary bipartite complex network in which the nodes and weighted links represent the players and transactions respectively the strong stable equilibrium of the network is applied to detect possible market equilibria obtained through a dynamic game with incomplete and imperfect information in which the players form an evolutionary network while trying to maximize their own utilities the model is conceptually illustrated with a four bus test system and then applied to the ieee30 test system to analyze the impact of the transmission network and information on the equilibria and market performance

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

elicitation of honest preferences for the assignment of individuals to positions the problem of eliciting honest preferences from individuals who must be assigned to a set of positions is considered individuals know that they will be charged for the positions to which they are assigned a set of prices that provide no incentive for the individual to misrepresent his preferences is suggested it is shown that these prices constitute an element of the optimal solution to the dual of a linear programming assignment problem both the optimal allocation and the prices to be charged can be derived by solving two linear programming problems once preferences have been elicited the procedure can usefully be viewed as a simulation of a competitive market under conditions where such a market cannot be expected to function well it results in an efficient allocation where all resources are valued at their opportunity costs and consumer surplus is maximized its outcome thus has the desirable properties of competitive market equilibria

bargaining in a network of buyers and sellers abstract we analyze bargaining between buyers and sellers who are connected by an exogenously given network players can make repeated alternating public offers that may be accepted by any of the responders linked to each specific proposer our purpose is to find the conditions of the network which drive the price distribution in equilibrium this paper uses graph theory tools to provide necessary and sufficient conditions regarding the architecture of networks for the subgame perfect equilibrium of the bargaining game to coincide with the walrasian outcome

ethnic fractionalization in an african labour market abstract we find evidence of ethnic fractionalization and its consequences in an african labour market we consider earnings differentials between members of different ethnic groups and between employers relatives unrelated co ethnics and other workers in the ghanaian manufacturing sector variations in a standard set of observed workers characteristics explain a large proportion of the earnings differentials between ethnic groups however the greatest proportion is explained by the ethnic fractionalization of the labour market combined with variations in employers characteristics workers who are related to their employers earn a premium and there is statistical discrimination in favour of inexperienced co ethnic workers

second sourcing as a commitment monopoly incentives to attract competition we show that a new product monopolist may benefit from delayed competition if consumers incur setup costs setup costs create a dynamic consistency problem the monopolist cannot guarantee low future prices once customers have incurred those costs we show that if customers anticipate this problem the monopolist s profits can be improved through ex ante commitment to competition in the post adoption market if setup costs are large if setup costs are small the monopolist can typically achieve the same level of profits without price commitment as with

a theoretical foundation for the undercut proof equilibrium abstract this paper develops a theoretical foundation for the undercut proof equilibrium see shy 1996 shy 2002 morgan and shy 2015 in a general spatial setting the set of undercut proof prices is equivalent to the core of a non transferable utility coalitional game played on the set of outcomes that are feasible in bertrand competition the result depends critically on two conditions first firms must have unlimited capacity and constant marginal costs second the goods produced by firms must only be differentiated by the spatial characteristics of the market an application to network markets shows how the undercut proof equilibrium can be used to describe stable price dispersion and persistent performance differences

the formation of risk sharing networks this paper examines the formation of risk sharing networks in the rural philippines we find that geographic proximity possibly correlated with kinship is a major determinant of mutual insurance links among villagers age and wealth differences also play an important role in contrast income correlation and differences in occupation are not determinants of network links reported network links have a strong effect on subsequent gifts and loans gifts between network partners are found to respond to shocks and to differences in health status from this we conclude that intra village mutual insurance links are largely determined by social and geographical proximity and are only weakly the result of purposeful diversification of income risk the paper also makes a methodological contribution to the estimation of dyadic models

contracting with qualified suppliers in an extension of the laffont tirole model a buyer fully qualifies a set of suppliers ex ante and awards production to the most efficient ex post the buyer s incomplete information about production costs biases ex ante market structure in favor of a greater number of qualified suppliers further extensions that allow product differentiation and learning by doing suggest explanations for split production awards and less than fully qualified suppliers it may be difficult to specify ex ante precisely how the assets will be employed in production grossman and hart 1986 once relationship specific assets are in place the characteristics of the transaction and the gains from trade will be determined by ex post contracting between the buyer and the seller a safeguard for the buyer is to contract with more than one potential supplier to invest in the relationship specific assets required for production then after production require ments become clear the buyer can structure a competition between these suppliers for the right to produce this article analyzes when a second sourcing policy is desirable and how the buyer should structure it asanuma s 1989 description of the two vendor policy of automobile manufac turers in japan provides a context for the analysis japanese automobile manufac turers contract out for various kinds of components for example headlamps brakes or steering columns the common practice is to purchase each component from a small and relatively stable group of qualified suppliers with the purposes of assuring supply and of creating competition moreover for a particular part for a particular model there is a tendency for an automobile manufacturer to purchase from a single supplier in the group for the life of the model my understanding from interviews and the trade press is that u s automobile manufacturers also sole source from a select group of qualified suppliers but with

equilibrium in a market with sequential bargaining this paper considers a market where pairs of agents who are interested in carrying out a transaction are brought together by a stochastic process and upon meeting initiate a bargaining process over the terms of the transaction the basic bargaining problem is treated with the strategic approach the paper derives the steady state equilibrium agreements analyzes their dependence on market conditions such as the relative numbers of agents of different types and discusses their relations with the competitive equilibrium outcome and other results in the search equilibrium literature this paper considers a market that operates in the following way pairs of agents who have mutual interest in carrying out a transaction are brought together by a stochastic process when two agents meet they initiate a bargaining process over the terms of the transaction if two agents reach an agreement a transaction takes place and they leave the market of course the bargaining positions and hence the agreement reached in any particular meeting will be affected by the conditions prevailing in the market these will include the chances that each of the negotiating parties have of meeting other partners in the event that the agreement in the current negotiations is delayed also the expected length of time required to achieve an alternative transaction and the expected behavior of alternative partners the study of such a market mechanism is of interest for two reasons firstly it captures some realistic aspects of the trade in certain specific markets e g asset markets such as housing and some labor markets secondly it contributes to an understanding of the micro mechanisms of price formation and their role in shaping market outcomes in both cases the features studied are largely neglected in the traditional market equilibrium analyses the related literature includes the articles by diamond 4 5 diamond and maskin 6 mortensen 8 9 and zusman and bell 13 these articles consider markets of the type described above in which transactions are concluded at pairwise meetings of agents the major difference between our work and these articles is in the approach to the basic bargaining problem in the cited articles it is assumed that a meeting is concluded with an instantaneous agreement which divides the associated surplus in an arbitrary predetermined way when the surplus is assumed to be divided equally the division rule is in fact nash s axiomatic bargaining solution in contrast the present paper treats the basic bargaining problem with the strategic approach see rubinstein 19 which constitutes an attempt to look into the bargaining black box this approach explicitly models the time dimension of the bargaining process describes in detail the bargaining procedure and justifies the agreement as a perfect equilibrium in

bilateral bargaining in networks abstract each connected pair of nodes in a network can jointly produce one unit of surplus a maximum number of linked nodes is selected in every period to bargain bilaterally over the division of the surplus according to the protocol proposed by rubinstein and wollinsky equilibrium in a market with sequential bargaining econometrica 53 1985 1133 1150 all pairs which reach an agreement obtain the discounted payoffs and are removed from the network this bargaining game has a unique subgame perfect equilibrium that induces the dulmage mendelsohn decomposition partition of the bipartite network of the set of nodes in this network

price formation on the marseille fish market evidence from a network analysis abstract the empirical analysis of fish markets always reveals strong price dispersion for homogeneous or very similar goods the problem is how to explain this price dispersion on a market where there is no evident arbitrage explanations proposed by different authors include differences in organization the characteristics of the good and the influences of social interactions between buyers and sellers in line with the last of these three approaches we consider the fish market of marseille as a seller seller network we start by examining the influence of market interactions through a static and then a dynamic econometric model we then analyze the role of the seller s position in the network we bring to light a surprising paradox in that the sellers who share the most buyers with competitors i e the most central sellers charge the highest prices

a theory of buyer seller networks this paper introduces a new model of exchange networks rather than markets of buyers and sellers it begins with the empirically motivated premise that a buyer and seller must have a relationship a link to exchange goods networks buyers sellers and the pattern of links connecting them are common exchange environments this paper develops a methodology to study network structures and explains why agents may form networks in a model that captures characteristics of a variety of industries the paper shows that buyers and sellers acting strategically in their own self interests can form the network structures that maximize overall welfare

bargaining dynamics in exchange networks abstract we consider a one sided assignment market or exchange network with transferable utility and the dynamics of bargaining in such a market our dynamical model is local involving iterative updates of offers based on estimated best alternative matches in the spirit of pairwise nash bargaining agents are not strategic in our model we establish that when a balanced outcome a generalization of the pairwise nash bargaining solution to networks exists our dynamics converges rapidly to such an outcome

the inefficiency of refinancing why prepayment penalties are good for risky borrowers abstract this paper provides a theoretical analysis of the efficiency of prepayment penalties in a dynamic competitive lending model with risky borrowers and costly default when considering improvements in the borrower s creditworthiness as one of the reasons for refinancing mortgages we show that refinancing penalties can be welfare improving and that they can be particularly beneficial to riskier borrowers in the form of lower mortgage rates reduced defaults and increased availability of credit thus a high concentration of prepayment penalties among the riskiest borrowers can be an outcome of efficient equilibrium in a mortgage market we also provide empirical evidence that is consistent with the key predictions of our model

vertical mergers and product differentiation this paper presents an equilibrium theory of vertical mergers that incorporates strategic behaviors in the hotelling type location model this enables one to consider the relationship between downstream firms strategies for product differentiation and vertical integration i show that vertical integration enhances the degree of product differentiation of the integrated firm under some conditions partial integration arises in equilibrium which may increase the profit of the nonintegrated downstream firm the paper also discusses the welfare implications of vertical integration

making a market mass privatization in the czech and slovak republics the author assesses the czechoslovak mass privatization program for speed equity and corporate governance the program transferred claims on assets in 1 491 enterprises assets worth about 10 7 billion to the 8 5 million citizens who participated in the scheme the entire cycle of project preparation public information and nationwide simultaneous bidding took 14 months this was equivalent to privatizing more than three medium scale and large scale enterprises on average per day equity objectives were achieved by transferring equal claims equivalent to about 1 250 per person to all participants and by putting in place a transparent and decentralized process the government s role was simple to provide a framework and a set of rules for potential firms managers and shareholders to find each other the scheme s design based on simultaneous sequential bidding rounds worked to put information about enterprise values into the public domain by allowing increasingly informed bidders to interact the structure of ownership that emerged will have very different implications for corporate governance enterprises in the czech republic and those that sold for high prices in the bidding rounds are characterized by a greater concentration of shareholdings those in the slovak republic and those that sold for lower prices have more diffuse ownership structures the mass privatization scheme served to quickly differentiate the enterprises with favorable prospects from those with unfavorable prospects under current conditions but enterprises that could have survived in some form if they had been restructured before privatization or enterprises that could have been viable but lacked effective governance were sacrificed for the sake of speed and decentralization

from exogenous to endogenous economic networks internet applications economic agents behaviour is affected by their position in a network either exogenous or endogenous in which they interact with a sub set of neighbours only the network s links which may be generated by vertical and or horizontal relations or by more complex morphologies may explain the transition between dynamic equilibria and the instability of economic aggregates moreover networks shape strategic interaction among agents by determining their strategies the problem of access and interconnection particularly relevant in the internet is perhaps the best example a two way feedback between strategies and network structures arises instead when links are endogenous those features are clearly shown in the mechanism underlying the formation of peering links an dr d networks

r d networks we develop a model of strategic networks that captures two distinctive features of interfirm collaboration bilateral agreements and nonexclusive relationships our analysis highlights the relationship between market competition firms incentives to invest in r d and the architecture of collaboration networks in the absence of firm rivalry the complete network where each firm collaborates with all others is uniquely stable industry profit maximizing and efficient by contrast under strong market rivalry the complete network is stable but intermediate levels of collaboration and asymmetric networks are more attractive from a collective viewpoint this suggests that competing firms may have excessive incentives to form collaborative links

price dispersion in stationary networked markets abstract different sellers often sell the same good at different prices using a strategic bargaining model i characterize how the equilibrium prices of a good depend on the interaction between its sellers costs its buyers values and a network capturing various frictions associated with trading it in contrast to the standard random matching model of bargaining in stationary markets i allow agents to strategically choose whom to make offers to which qualitatively changes how the network shapes prices as in the random matching model the market decomposes into different submarkets and in the limit as bargaining frictions vanish the law of one price holds within but not across them but strategic choice of partners changes both how the market decomposes into different submarkets and the determinants of each submarket s price

buyers strategies entry barriers and competition in markets where sellers have customer specific investments and buyers can make credible but costly commitments to switch suppliers buyers strategies attenuate the market power of sellers furthermore since current prices and a buyer s decision to switch suppliers are related limit pricing becomes an equilibrium limit prices increase with the time it takes a buyer to switch suppliers and with buyers switching costs but fall with the level of sunk investments thus sunk investments may restrain the sellers ability to exert market power the paper questions then the standard inverse relationship between market performance and sunk investments

principles of network development and evolution an experimental study this paper reports on an experimental investigation of the evolution of networks and the individual decision making processes that guide it inasmuch as there is no history of experimental work on network formation part of the paper is devoted to the formulation of problems that can be examined experimentally the results are that networks composed of decentralized decision makers are capable of overcoming complex coordination and learning problems and converge to stationary when it does not occur significant and persistent inefficiencies can result the models of equilibration based on the principle of nash equilibrium are more reliable than models based on the alternative principles of efficiency seeking or focalness of the network configuration however individual decision making within networks is not in accordance with the simple decision rules of nash best response instead we observed complicated strategies that appear to trade short term profits in order to signal to and teach other agents the strategies required for long term profit maximization

bilateral oligopoly the efficiency of intermediate goods markets abstract we show that intermediate goods markets may be efficient despite the presence of commonly accepted signs of market failure such as high concentration both among sellers and buyers sparse trading networks price dispersion and externalities the results are derived in an extensive form model of bilateral bargaining with multiple buyers and multiple sellers and with externalities between the negotiations we also characterize the structure of the endogenous trading network i e how firms choose trading partners prices are dispersed and depend on both the concentration of capital and the concentration of sales consistent with some stylized facts on buyer power

equilibria in networks we study a model in which two carriers choose networks to connect cities and compete for customers we show that if carriers compete aggressively e g bertrand like behavior one carrier operating a single hub spoke network is an equilibrium outcome competing hub spoke networks are not an equilibrium outcome although duopoly equilibria in nonhub networks can exist if carriers do not compete aggressively an equilibrium with competing hub spoke networks exists as long as the number of cities is not too small we provide conditions under which all equilibria consist of hub spoke networks

development and social capital abstract this paper examines social capital and its relation with economic development we focus on the role that interpersonal relationships play in social exchange whether through the market or through the provision of public goods by facilitating search and trust social capital can increase the efficiency of social exchange where formal institutions are weak but the benefits from social capital are likely to be unequally distributed given these features documenting empirically the benefits of social capital is complicated by the presence of negative and positive externalities and by the existence of leadership and group effects lessons for development policy are drawn at the end

syndication institutionalization and lottery play1 why do people play the lottery since lottery tickets are assets with negative expected return lottery play challenges the basic assumptions of economic theory this article approaches lottery play from a networks perspective and focuses on syndicate play a comparison of the development of lottery markets in germany austria spain and portugal from the 17th century onward shows that lottery play declined with rising incomes except in countries in which syndicate play diffused widely namely spain and to a lesser extent portugal although syndicating originated among the relatively poor as a response to an increase in lottery prices it persisted even when individual play became affordable this article contends that syndicating endured because of an institutionalization process by which lottery tickets have transformed from purely economic assets into symbolic carriers of interpersonal ties that convey membership and status position in relevant social networks

historical property rights sociality and the emergence of impersonal exchange in long distance trade this laboratory experiment explores the extent to which impersonal exchange emerges from personal exchange with opportunities for long distance trade we design a three commodity production and exchange economy in which agents in three geographically separated villages must develop multilateral exchange networks to import a good only available abroad for treatments we induce two distinct institutional histories to investigate how past experience with prop erty rights affects the evolution of specialization and exchange we find that a history of unenforced property rights hinders our subjects ability to develop the requisite personal social arrangements to support specialization and effec tively exploit impersonal long distance trade jel c90 d23 d5 p 4

imperfect monitoring in communication networks individuals in many social networks imperfectly monitor other individuals network relationships this paper shows that in a model of a communication network imperfect monitoring leads to the existence of many inefficient equilibria reasonable restrictions on actions or on beliefs about others actions can however eliminate many of these inefficient equilibria even with imperfect monitoring star networks known to be efficient in many settings are shown to have desirable monitoring characteristics more generally this paper provides a formal framework in which to study incorrect perceptions as an equilibrium phenomenon in social networks

the english auction with differentiated commodities abstract we study economies with indivisibilities that satisfy the gross substitutes gs condition we define an excess demand set with the property that increasing the prices of all goods in excess demand eventually leads to the smallest walrasian prices this procedure is a generalization of the auction studied by g demange d gale and m j sotomayor polit econ 94 1986 863 872 in our auction truthful revelation of demand is a perfect bayesian equilibrium if the smallest walrasian prices correspond to the vickrey clarke groves payments however no dynamic auction can reveal sufficient information to implement the vickrey mechanism if all gs preferences are allowed journal of economic literature classification numbers d4 d44 d5 d51

bargaining in stationary networks we study an infinite horizon game in which pairs of players con nected in a network are randomly matched to bargain players who reach agreement are replaced by new players at the same positions in the network we show that all equilibria are payoff equivalent the payoffs and the set of agreement links converge as players become patient several new concepts mutually estranged sets partners and shortage ratios provide insights into the relative strengths of the positions in the network we develop a procedure to deter mine the limit equilibrium payoffs for all players characterizations of equitable and nondiscriminatory networks are also obtained jel c78 d85 competitive equilibrium theory assumes large and anonymous markets in which every buyer can trade with every seller underlying these assumptions are standard goods and services that may be traded at low transaction costs by agents who are not in specific relationships with one another however in many markets goods and services are heterogeneous e g cars apartments or need to be tailored to particular needs e g manufacturing inputs technical support furthermore trad ing opportunities may depend on transportation costs social relationships infor mation advertising trust technological compatibility joint business opportunities free trade agreements etc in such cases it is natural to model the market using a network where only pairs of connected agents may engage in exchange new theories are needed to explore the influence of the network structure on market outcomes many questions arise how does an agent s position in the net work determine his bargaining power and the local prices he faces who trades with whom and on what terms when are prices uniform in the network one possible conjecture is that an agent s bargaining power is determined by his relative number of connections in the network however this simple theory is implausible consider the network of four sellers located at the top nodes and nine buyers located at the bottom nodes depicted in figure 1 assume that each seller supplies one unit of a homogeneous indivisible good each buyer demands one unit of the good and all buyers have identical values for the good the buyer located in the middle has the largest number of links in the network as he is connected to each

non cooperative networks in oligopolies in an oligopoly prior to competing in the market firms have an opportunity to pick up externalities from other firms by setting links the links formation defines an industrial network we study the incentives for firms to form links and the effect of this links formation on the architecture of the resulting networks our analysis shows that equilibrium networks differ dramatically depending on the nature of market competition cournot or bertrand more precisely in the case of cournot oligopoly we should expect to see networks in which each firm obtains access to externalities of either all firms or no firm in the case of bertrand oligopoly we should expect to see networks in which one firm derives benefits from externalities of all other firms while the latter get no externality we also present some results on the architecture of socially efficient networks

strong price of anarchy abstract a strong equilibrium is a pure nash equilibrium which is resilient to deviations by coalitions we define the strong price of anarchy spoa to be the ratio of the worst strong equilibrium to the social optimum differently from the price of anarchy defined as the ratio of the worst nash equilibrium to the social optimum it quantifies the loss incurred from the lack of a central designer in settings that allow for coordination we study the spoa in two settings namely job scheduling and network creation in the job scheduling game we show that for unrelated machines the spoa can be bounded as a function of the number of machines and the size of the coalition for the network creation game we show that the spoa is at most 2 in both cases we show that a strong equilibrium always exists except for a well defined subset of network creation games

liquidity risk in sequential trading networks abstract this paper studies a model of intermediated exchange with liquidity constrained traders intermediaries are embedded in a trading network and their financial capacities are private information we characterize our model s monotone pure strategy equilibrium agents earn positive intermediation rents in equilibrium an experimental investigation supports the model s baseline predictions concerning agents strategies price dynamics and the division of surplus while private financial constraints inject uncertainty into the trading environment our experiment suggests they are also a behavioral speed bump preventing traders from experiencing excessive losses due to overbidding

anonymous market and group ties in international trade abstract history provides many examples of cohesive groups dispersed over several countries who exploit the ties between their members to gain entry into foreign markets the phenomenon is well established empirically and noteworthy because it suggests the importance of informational barriers in international transactions we present a simple model where output is produced through a joint venture and agents have complete information domestically but are unable to judge the quality of their match abroad a minority of individuals otherwise identical to all others can exploit complete information in international matches between group members if they so choose group ties increase aggregate trade and income but hurt the anonymous market because they deprive it disproportionately of the group s more productive members

vertical integration in the presence of upstream competition we analyse vertical integration when there is upstream competition and compare outcomes to the case where upstream assets are owned by a single agent i e upstream monopoly in so doing we make two contributions to the modelling of strategic vertical integration first we base industry structure namely the ownership of assets firmly within the property rights approach to firm boundaries second we model the potential multilateral negotiations using a fully specified non cooperative bargaining model designed to easily compare outcomes achieved under upstream competition and monopoly given this we demonstrate that vertical integration can alter the joint payoffs of integrating parties in ex post bargaining however this bargaining effect is stronger for firms integrating under upstream competition than upstream monopoly we also consider the potential for integration to internalise competitive externalities in manner that cannot be achieved under non integration we demonstrate that ex post monopolization is more likely to occur when there is an upstream monopoly than when there is upstream competition our general conclusion is that the simple intuition that the presence of upstream competition can mitigate and reduce the incentives for socially undesirable vertical integration is misplaced and depending upon the strength of downstream competition i e product differentiation the opposite could easily be the case journal of economic literature classification number l42

quotas as options valuation and equilibrium implications abstract this paper presents formulae for the values of quota licenses in stochastic environments that are based on observable parameters and examines the impact of parameter changes on domestic equilibrium we show that the option pricing methodology currently used widely in the finance literature may be applied to the valuation of licenses in a potentially wide range of market environments

mechanisms for a spatially distributed market abstract we consider the problem of a spatially distributed market with strategic agents a single good is traded in a set of independent markets where shipment between markets is possible but costly the problem has previously been studied in the non strategic case in which it can be analyzed and solved as a min cost flow problem we consider the case where buyers and sellers are strategic our first result gives a double characterization of the vcg prices first as distances in a certain residue graph and second as the minimal for buyers and maximal for sellers equilibrium prices this provides a computationally efficient individually rational and incentive compatible welfare maximizing mechanism this mechanism is necessarily not budget balanced and we also provide a budget balanced mechanism which is also computationally efficient incentive compatible and individually rational that achieves high welfare finally we present results for some extensions of the model

social capital inclusive networks and economic performance abstract empirical studies show that the relationship between social capital and economic performance is ambiguous the paper points to the potential trade off between the sustainability of self enforcement and the magnitude of gains from trade in social networks as an explanation based on an infinitely repeated multi player prisoners dilemma it is shown how self enforcement of cooperation within a network is influenced by its inclusiveness its communication capacity and the complexity of the exchange setting the paper shows that inclusive social capital can combine both low enforcement costs and high gains from trade even in a complex exchange setting

trading networks with price setting agents abstract in a wide range of markets individual buyers and sellers trade through intermediaries who determine prices via strategic considerations typically not all buyers and sellers have access to the same intermediaries and they trade at correspondingly different prices that reflect their relative amounts of power in the market we model this phenomenon using a game in which buyers sellers and traders engage in trade on a graph that represents the access each buyer and seller has to the traders we show that the resulting game always has a subgame perfect nash equilibrium and that all equilibria lead to an efficient allocation of goods finally we analyze trader profits in terms of the graph structure roughly a trader can command a positive profit if and only if it has an essential connection in the network thus providing a graph theoretic basis for quantifying the amount of competition among traders

theorizing regional economic performance and the changing territorial division of labour dunford m 2003 theorizing regional economic performance and the changing territorial division of labour reg studies 37 839 854 after identifying the general mechanisms underling the centripetal and centrifugal forces whose interplay shapes the relative performance of regional economies a case is made for disaggregating macroeconomic indicators and examining the sectoral and occupational changes they conceal once regional performance is seen as reflecting underling changes in the profiles of regional economies it is clear that research should examine the forces that determine the changing territorial division of labour to explain the latter a conceptual framework is presented this framework combines value chain approaches to the strategies of individual enterprises and analyses of the impact on the performance of enterprises of their wider social environment explicit links are established between this framework and some of the insights of the new economic geography dunford m 2003 la theor

a strategic model of social and economic networks we study the stability and efficiency of social and economic networks when self interested individuals can form or sever links first for two stylized models we characterize the stable and efficient networks there does not always exist a stable network that is efficient next we show that this tension persists generally to assure that there exists a stable network that is efficient one is forced to allocate resources to nodes that are not responsible for any of the production we characterize one such allocation rule the equal split rule and another rule that arises naturally from bargaining of the players

delegated monitoring versus arm s length contracting abstract this paper analyzes the optimal organization of input suppliers in a procurement context we discuss when a top firm chooses to induce information sharing and active coordination between its suppliers consolidation rather than having them contract at arm s length delegation in designing the organization the firm anticipates that different supplier networks have different costs of inducing information revelation from suppliers when the cost of information sharing varies the optimal organization exhibits various discrete degrees of consolidation there is excessive arm s length contracting compared to the case where the top firm controls this organizational choice itself the paper offers also a methodology to study in a unified framework various organizational forms separately analyzed in the literature

farsighted network formation this paper studies a model of dynamic network formation when individuals are farsighted players evaluate the desirability of a current move in terms of its consequences on the entire discounted stream of payoffs we define a concept of equilibrium which takes into account farsighted behavior of agents and allows for limited cooperation amongst agents we show that an equilibrium process of network formation exists we also show that there are valuation structures in which no equilibrium strategy profile can sustain efficient networks we then provide sufficient conditions under which the equilibrium process will yield efficient outcomes

networks versus vertical integration we construct a theory to compare vertically integrated firms to networks of manufacturers and suppliers vertically integrated firms make their own specialized inputs in networks manufacturers procure specialized inputs from suppliers that in turn sell to several manufacturers the analysis shows that networks can yield greater social welfare when manufacturers experience large idiosyncratic demand shocks individual firms may also have the incentive to form networks despite the lack of long term contracts the analysis is supported by existing evidence and provides predictions as to the shape of different industries

multi item auctions a collection of items is to be distributed among several bidders and each bidder is to receive at most one item assuming that the bidders place some monetary value on each of the items it has been shown that there is a unique vector of equilibrium prices that is optimal in a suitable sense for the bidders in this paper we describe two dynamic auction mechanisms one achieves this equilibrium and the other approximates it to any desired degree of accuracy

the informational divide we propose a model of price competition where consumers exogenously differ in the number of prices they compare our model can be interpreted either as a non sequential search model or as a network model of price competition we show that i if consumers who previously just sampled one firm start to compare more prices all types of consumers will expect to pay a lower price and ii if consumers who already sampled more than one price sample even more prices then there exists a threshold the informational divide such that all consumers comparing fewer prices than this threshold will expect to pay a higher price whereas all consumers comparing more prices will expect to pay a lower price than before thus increased search can create a negative externality and it is not necessarily beneficial for all consumers

nash in nash bargaining a microfoundation for applied work a nash equilibrium in nash bargains has become the workhorse bargaining model in applied analyses of bilateral oligopoly this paper proposes a non cooperative foundation for nash in nash bargaining that extends the rubinstein 1982 model to multiple upstream and downstream rms assuming there exists gains from trade for each rm pair we prove that there exists an equilibrium with immediate agreement and negotiated prices that correspond to rubinstein prices if and only if the marginal contribution of a set of agreements is weakly greater than the sum of the agreements marginal contributions we provide stronger conditions under which equilibrium prices are unique

sanctions in networks abstract in this paper we contribute to the sender target models of sanctions by explicitly incorporating the linkages social political or economic that bind the sender and target to other agents given any network model and architecture we draw attention to two factors that play a key role in determining the efficacy of sanctions in reducing the frequency of violations these are respectively strategic complementaritiesbetween the sanctioning action deleting link with target and number of direct links of the sender and the externalities imposed on the sender by third parties we examine the role played by these factors both in the short run when links can only be deleted and the long run when links can also be added as well as when sanctions are unilateral the sender can only delete own links or multilateral the sender can impose on common allies to sever links to the target our analysis allows an active role to the target to build an opposing coalition to deflect sanctions and to third parties to engage in sanction busting it also extends to multiple senders and targets existence of interest groups within sender and target with dissimilar objectives and signed networks allowing both antagonistic and cordial bilateral relationships

aggregate demand idle time and unemployment this paper develops a model of unemployment fluctuations the model keeps the architecture of the barro and grossman 1971 general disequilibrium model but replaces the disequilibrium framework on the labor and product markets by a matching framework on the product and labor markets both price and tightness adjust to equalize supply and demand there is one more variable than equilibrium condition on each market so we consider various price mechanisms to close the model from completely flexible to completely rigid with some price rigidity aggregate demand influences unemployment through a simple mechanism higher aggregate demand raises the probability that firms find customers which reduces idle time for firms employees and thus increases labor demand which in turn reduces unemployment we use the comparative statics predictions of the model together with empirical measures of quantities and tightnesses to re examine the origins of labor market fluctuations we conclude that 1 price and real wage are not fully flexible because product and labor market tightness fluctuate significantly 2 fluctuations are mostly caused by labor demand and not labor supply shocks because employment is positively correlated with labor market tightness and 3 labor demand shocks mostly reflect aggregate demand and not technology shocks because output is positively correlated with product market tightness

communication and coordination in social networks i model people in a coordination game who use a communication network to tell each other their willingness to participate the minimal sufficient networks for coordination can be interpreted as placing people into a hierarchy of social roles or stages initial adopters then followers and so on down to late adopters a communication network helps coordination in exactly two ways by informing each stage about earlier stages and by creating common knowledge within each stage we then consider two examples first we show that low dimensional networks can be better for coordination even though they have far fewer links than high dimensional networks second we show that wide dispersion of insurgents people predisposed toward participation can be good for coordination but too much dispersion can be bad although collective action depends on both social structure and individual incentives these integral aspects have been formalized separately in the fields of social network theory and game theory by considering them together this paper engages the classic question of which structures are conducive to coordination and shows that structure and strategy are related in a mutually interesting way here we consider a coordination game in which each person wants to participate only if others participate social structure is thought of as a communication network by which people tell each other their willingness to participate each person knows whether her neighbours in the network are willing but does not know about anyone else our model is thus a game of incomplete information in which each person given his local knowledge decides whether to participate the main result is a characterization of the minimal sufficient networks for coordination in terms of a hierarchy of social roles or stages initial adopters then followers and so on down to late adopters for example a communication network helps coordination in exactly two ways by informing each stage about earlier stages and by creating common knowledge within each stage we also consider two simple examples first we show that low dimension or strong link networks can be better for coordination even though they have far fewer links than high dimension or weak link networks second we show that wide dispersion of insurgents people predisposed toward participation can be good for coordination but too much dispersion can be bad this paper is built on the assumption that the most basic and common mechanism for coordination is the i ll go if you go mechanism individuals first communicate with each other about their preferences and then each individual chooses whether to participate or not hence a person s participation depends on what he knows about his neighbours it does not depend solely on their participation itself either through learning adaptation or social influence the physical analogies of contagion or diffusion are not

does competition solve the hold up problem in an environment in which heterogeneous buyers and sellers undertake ex ante investments the presence of market competition for matches provides incentives for investment but may leave inefficiencies namely hold up and coordination problems this paper shows using an explicitly non cooperative model that when matching is assortative and investments precede market competition buyers investments are constrained efficient while sellers marginally underinvest with respect to what would be constrained efficient however the overall extent of this inefficiency may be large multiple equilibria may arise one equilibrium is characterized by efficient matches but there can be additional equilibria with coordination failures

networks in the modern economy mexican migrants in the u s labor market this paper attempts to identify job networks among mexican migrants in the u s labor market the empirical analysis uses data on migration patterns and labor market outcomes based on a sample of individuals belonging to multiple origin communities in mexico over a long period of time each community s network is measured by the proportion of the sampled individuals who are located at the destination the united states in any year we verify that the same individual is more likely to be employed and to hold a higher paying nonagricultural job when his network is exogenously larger by including individual fixed effects in the employment and occupation regressions and by using rainfall in the origin community as an instrument for the size of the network at the destination

a decentralized model of information pricing in networks we propose a recursive method of pricing an information good in a network of holders and demanders of this good the prices are determined via a unique equilibrium outcome in a sequence of bilateral bargaining games that are played by connected agents if the information is a homogenous non depreciating good without network effects we derive explicit formulae which elucidate the role of the link pattern among the players particularly we find out that the equilibrium price is intimately related to the existence of cycles in the network it is zero if a cycle covers the trading pair and it is proportional to the direct and indirect utility that the good generates otherwise

efficiency in decentralized oligopolistic markets the paper analyzes quantity competition in economies in which a network describes the set of feasible trades a model is presented in which the identity of buyers of sellers and of intermediaries is endogenously determined by the trade flows in the economy the analysis first considers small economies and provides sufficient conditions for equilibrium existence a characterization of prices and flows and some negative results relating welfare to network structure the second and central part of the analysis considers behavior in large markets and presents necessary and sufficient conditions on the network structure for equilibria to be approximately efficient when the number of players is large

systems competition and network effects this paper discusses firm behavior market performance and the public and private institutions that arise in systems markets i e markets where consumers use compatible components together to generate benefits in such markets which include communications networks and hardware software networks popular products are inherently more valuable these network effects can drive corporate strategies and are critical in understanding innovation in many high technology markets the discussion here emphasizes the dynamics of consumer adoption decisions in the presence of network effects competition between incompatible systems and how suppliers choose which components are compatible and which are not

the formation of a core periphery structure in heterogeneous financial networks recent empirical evidence suggests that nancial networks exhibit a core periphery network structure this paper aims at giving an economic explanation for the emergence of such a structure using network formation theory focusing on intermediation benets we nd that a core periphery network cannot be unilaterally stable when agents are homogeneous the best response dynamics converge to a unique unilaterally stable outcome ranging from an empty to denser networks as the costs of linking decrease a core periphery network structure can form endogenously however if we allow for heterogeneity among agents in size we show that our model can reproduce the observed core periphery structure in the dutch interbank market for reasonable parameter values

heterogeneous beliefs in over the counter markets the behavior and stability of over the counter markets is of central concern to regulators little is known however about how the structure of these markets determine their properties in this paper we consider an over the counter market populated by boundedly rational heterogeneous traders in which the structure is represented by a network stability is found to decrease as the market becomes less well connected however the configuration of connections has a significant effect the presence of hubs such as those found in scale free networks increases stability and decreases volatility whilst small world short cut links have the opposite effect volatility in the fundamental value increases market volatility however volatility in the riskless asset returns has an ambiguous effect

markov equilibria in a model of bargaining in networks abstract we study the markov perfect equilibria mpes of an infinite horizon game in which pairs of players connected in a network are randomly matched to bargain players who reach agreement are removed from the network without replacement we establish the existence of mpes and show that mpe payoffs are not necessarily unique a method for constructing pure strategy mpes for high discount factors is developed for some networks we find that all mpes are asymptotically inefficient as players become patient

formation of buyer seller trade networks in a quality differentiated product market we examine the formation of buyer seller links when exchange can take place only if such a link exists sellers produce products of different qualities and multiple sellers can form a sellers association to pool their customers setting uniform prices buyers form trade links with individual sellers or sellers associations we show which buyer seller links will form and find the set of links that are stable and show how these links influence prices we also show that a trade network mismatch may occur where a high quality good remains unsold even without an economy wide excess supply of goods jel classification d40 d51 d82