preferential trading arrangements as strategic positioning abstract we analyze a three country model of trade negotiations in which countries can form bilateral free trade areas bilateral customs unions or a trilateral preferential trading arrangement and can continue negotiating after reaching an agreement in contrast to the literature on multilateral bargaining the set of agreements can form a nonpartitional network while in contrast to the network literature players can reach multilateral agreements patient enough countries only reach bilateral agreements if insiders gain more than outsiders which allows them to manipulate the status quo in subsequent negotiations however a hub and spoke pattern may then emerge and insiders then dissipate the advantages of strategic positioning we also use variants on the model to explain why a us commitment not to bargain bilaterally sustained progress at gatt negotiations and the rarity of open access preferential trading arrangements

fringe benefits and small businesses evidence from the federal reserve board small business survey data from the 1993 national survey of small businesses nssbf is used to analyse the factors affecting the provision of pensions and health insurance by small businesses the race of the business owner is found to impact the provision of taxadvantaged fringe benefits even after accounting for a wide range of other economic and demographic variables it is not possible to determine why owner race impacts the provision of fringe benefits by small businesses but the significance of the race variable might reflect a lower level of marketing effort by financial service firms in minority dominated communities the owner education variable which is also significant in both the pension and health insurance models could also be a proxy for the availability of general information about the importance of fringe benefits with the exception of the sole proprietorship variable the demographic and economic variables appear to have similar effects on the provision of both pensions and health insurance by small busi

learning about a new technology pineapple in ghana this paper investigates the role of social learning in the diffusion of a new agri cultural technology in ghana we use unique data on farmers communication patterns to define each individual s information neighborhood conditional on many potentially confounding variables we find evidence that farmers adjust their inputs to align with those of their information neighbors who were surpris ingly successful in previous periods the relationship of these input adjustments to experience further indicates the presence of social learning in addition applying the same method to input choices for another crop of known technol ogy correctly indicates an absence of social learning effects jel d83 013 033 q16

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

the effect of entry on r d networks we investigate the effect of potential entry on the formation and stability of r d networks considering farsighted firms we show that the presence of a potential entrant often alters the incentives of incumbent firms to establish an r d link in particular incumbent firms may choose to form an otherwise undesirable r d collaboration in order to deter the entry of a new firm moreover an incumbent firm may refrain from establishing an otherwise desirable r d collaboration expecting to form a more profitable r d link with the entrant finally potential entry may lead an inefficient incumbent to exit the market we also perform a welfare analysisand show that market and societal incentives are often misaligned

social networks and technology adoption in northern mozambique despite their potentially strong impact on poverty agricultural innovations are often adopted slowly using a unique household dataset on sunflower adoption in mozambique we analyse whether and how individual adoption decisions depend upon the choices of others in the same social networks since farmers anticipate that they will share information with others we expect farmers to be more likely to adopt when they know many other adopters dynamic considerations however suggest that farmers who know many adopters might strategically delay adoption to free ride on the information gathered by others we present empirical evidence that shows that the relationship between the probability of adoption and the number of known adopters is shaped as an inverse u in line with information sharing the network effect is stronger for farmers who report discussing agriculture with others the data contains information which is needed to ameliorate the identification issues that commonly arise in this context in particular social networks are precisely identified and in addition we can control for village heterogeneity and endogenous group formation

farsighted coalitional stability abstract i define the largest consistent set a solution concept which applies to situations in which coalitions freely form but cannot make binding contracts act publicly and are fully farsighted in that a coalition considers the possibility that once it acts another coalition might react a third coalition might in turn react and so on without limit i establish weak nonemptiness conditions and apply it to strategic and coalitional form games and majority rule voting i argue that it improves on the von neumann morgenstern stable set as it is usually defined but is consistent with a generalization of the stable set as in the theory of social situations journal of economic literature classification numbers c70 c71

market structure and discrimination the case of small businesses this paper examines bank market structure to draw inferences concerning the role of discrimination in credit markets for small businesses the authors analyze credit application and denial rates loans outstanding and interest rates across demographic groups this set of variables in combination with information on local bank market structure helps them distinguish among borrower preferences lender tastes and inadequate lender information as likely causes of differences in credit market experiences of small business operators from distinct demographic groups the authors find that white men and women can expect similar treatment in credit markets with some benefits to female owned firms located in concentrated banking markets minorities by contrast fare worse than whites moreover by appealing to becker s 1957 classic theories we find some clear evidence to support the view that prejudicial discrimination is at least partly to blame

learning and capacity expansion under demand uncertainty a competitive dynamic model of entry into a new industry is set up and both its positive and normative aspects are studied the main assumptions are that entry is sequential that it occurs under imperfect information on the size of the market and that better information becomes available as time goes on the gradual improvement in information is due to the fact that later waves of entrants are able to observe the profitability of earlier entrants the major results reported here under suitable restrictions are that the equilibrium rate of entry is monotonically decreasing over time and that at any given point in time it is smaller than the socially optimal one when a new market opens as a result of a product being newly invented for instance or when an existing market starts to expand uncertainty with respect to its size is likely to prevail as a result of this uncertainty entry of firms into such markets typically will occur in waves some firms will enter initially while others will wait to see the consequences of that initial entry if the experience of early entrants is favourable entry will continue otherwise entry will cease hence with the introduction of a new product two phases are associated the growth phase typified by positive operating profits for existing firms and expansion of productive capacity due to entry of new firms and the mature phase typified by erosion of profits and fixed total productive capacity empiricists estimating the time pattern of investments during the growth phase have found an s shaped diffusion curve see mansfield 1986 and gort and klepper 1982 the purpose of the present paper is to theoretically characterize these time patterns and to investigate their welfare properties any attempt to model the type of entry described above must account for differences in both entry dates and resultant earnings in other words the theory must explain why the realized earnings of different cohorts of firms are not equal often such ex post differences are reconciled by assuming heterogeneity with respect to some latent underlying characteristic managerial ability for instance and attributing differences in earnings to differences in that characteristic in this paper instead earning differentials are attributable to luck only ex ante all firms are technologically identical and equally capable of forecasting market prospects and rationally acting upon those forecasts ex post some firms turn out to have entered at the right time and are for that reason more profitable the model developed in this paper analyzes a parametric example of a sequential entry problem in which the uncertainty over market size is gradually resolved over time in a bayesian setting in an environment of perfect competition and constant returns toscale a free entry equilibrium concept is introduced and the aggregate implications of the time path of investments are derived i then compare this actual time path to the optimum this comparison is interesting because the equilibrium is analysed under the

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

farsighted stability in patent licensing an abstract game approach abstract this paper analyzes the negotiations made by an external patent holder and potential licensee firms in a new model of patent licensing assuming that they are all farsighted and characterizes the symmetric farsighted stable sets given a net profit of each licensee firm a set of outcomes is a symmetric farsighted stable set if and only if at any outcome in the set each licensee firm receives the net profit and the number of licensee firms maximizes the patent holder s profit provided that licensee firms obtain the net profits we also show the close relationship between the symmetric farsighted stable sets and the relative interior of the core further we confirm that the symmetric farsighted stable sets are the absolutely maximal farsighted stable sets ray and vohra forthcoming as well as the history dependent strongly rational expectation farsighted stable sets dutta and vartiainen forthcoming

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

allocating value among farsighted players in network formation we study the stability of networks when players are farsighted and allocations are determined endogenously the set of strongly efficient networks is the unique von neumann morgenstern farsightedly stable set with bargaining if the value function is anonymous component additive and top convex and the allocation rule is anonymous and component efficient moreover the componentwise egalitarian allocation rule emerges endogenously

a one stage model of link formation and payoff division abstract in this paper we introduce a strategic form model in which cooperation structures and divisions of the payoffs are determined simultaneously we analyze the cooperation structures and payoff divisions that result according to nash equilibria strong nash equilibria and coalition proof nash equilibria we find that no cycle will be formed if a player claims a positive amount for the formation of one of its links and that a player does not necessarily profit from a central position in a cooperation structure journal of economic literature classification numbers c71 c72

the problem of instream flows to obtain a surface water right in the arid american west private appropriators have been required to undertake actual physical diversion of the water that requirement largely negates the role of private contacting to preserve or enhance water flows for recreational wildlife and aesthetic purposes in this paper a model is developed and used to examine the courts rationale for denying private claims to instream flows the ways in which such claims can be made amenable to the prior appropriation system are explored the paper is motivated by the failure of public agencies to achieve an approximately optimal solution

bank information monopoly and trade credit do only banks have information about small businesses according to previous studies a bank can set a higher interest rate for small firms by establishing a lending relationship since information asymmetry limits competition between banks therefore the bank can acquire monopoly rent from small firms however if small firms can use trade credit which is another financial source the bank cannot extract monopoly rent in this article we examine whether small firms can use trade credit if the bank sets a higher interest rate using panel data of small firms in japan our analysis shows that when the interest rate the bank sets is too severe or worsened for the borrower the ratio of trade payables increases and the bank loses its amount of loans this result implies that trade creditors alleviate the problems of bank information monopolies in japan

behavioral biases in endogenous timing herding games an experimental study abstract we experimentally study behavior in an endogenous timing herding game we find that subjects respond to their type and to observed investment activity in a sensible way but there are also substantial departures from nash equilibrium some departures can be viewed as mere noise in decision making while other departures represent systematic biases reflecting subjects failure to appreciate subtle aspects of the game

decentralization duplication and delay we argue that although decentralization has advantages in finding low cost solutions these advantages are accompanied by coordination problems which lead to delay or duplication of effort or both consequently decentralization is desirable when there is little urgency or a great deal of private information but it is strictly undesirable in urgent problems when private information is less important we also examine the effect of large numbers and find that coordination problems disappear in the limit if distributions are common knowledge

an equilibrium analysis of information aggregation and fluctuations in markets with discrete decisions abstract this paper shows how the interaction between decentralized information gathering and discreteness of investment decisions at the individual level can generate random fluctuations in aggregate investment that involve occasionally large allocation errors this interaction is illustrated in a model in which private information is costly to acquire and prices reveal information the unique rational expectations equilibrium outcome of the model is shown to always be noisy and characterized by investment levels which may be high simply because uninformed investors are buying under the impression that the high price is a signal of good investment opportunities

peer effects in endogenous networks abstract this paper presents a model of strategic network formation with local complementarities in effort levels and positive local externalities results are obtained for a general class of payoff functions which subsumes the linear quadratic specification frequently used in theoretical and applied work we assume homogeneous agents and characterize equilibria for two sided and one sided link formation pairwise nash equilibrium networks are nested split graphs which are a strict subset of core periphery networks we highlight the relevance of the convexity of the value function for obtaining these structures more central agents are shown to exert more effort and obtain higher gross payoffs in equilibrium however net of linking cost central agents may obtain strictly lower net payoffs the curvature of the value function is also important for efficiency considerations these findings are relevant for many social and economic phenomena such as educational attainment criminal activity labor market participation and r d expenditures of firms

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

on industry life cycles delay entry and shakeout in beer brewing abstract this paper proposes a new explanation for industry shakeout an event evident in the life cycle of many industries in which the number of firms drops significantly in a short interval of time based on an in depth analysis of the shakeout in the united states beer brewing industry between 1880 and 1890 we propose that industry shakeouts naturally follow periods of mass entry by firms similar patterns are evident in two other industries we briefly examine the us automobile and tire industries while entry rates fluctuate broadly in all these industries we find that the timing of exit for a given cohort of entrants is remarkably similar over time the exit hazard rate is peaked in the first two years of every cohort s life and drops dramatically to low and stable levels for subsequent ages in this sense mass exit follows mass entry and does not require a deep explanation it is the mass entry evident in the data for these industries that requires an explanation we propose a theoretical model of information accumulation to explain entry into an industry entrepreneurs are uncertain about the profitability of the industry and this uncertainty is resolved through sufficient accumulation of information regarding the fortunes of incumbent firms delay in entry occurs solely due to the fact that it takes time to accumulate sufficient information to support more entry the resulting entry pattern from simulations of the model looks much like that observed in the industries we study

experimentation in markets we present a model of entry and exit with bayesian learning and price competition a new product of initially unknown quality is introduced in the market and purchases of the product yield information on its true quality we assume that the performance of the new product is publicly observable as agents learn from the experiments of others informational externalities arise we determine the markov perfect equilibrium prices and allocations in a single market the combination of the informational externalities among the buyers and the strategic pricing by the sellers results in excessive experimentation if the new product is launched in many distinct markets the path of sales converges to the efficient path in the limit as the number of markets grows in multi agent learning situations informational externalities may reduce the number of experiments undertaken below the socially efficient level as buyers choose among new experience goods or firms decide whether to adopt a new technology the availability of information from others decisions gives rise to a free rider problem rather than perform a costly experiment herself a buyer may opt to wait and see how the market evaluates the new product in this paper we develop a simple market model of experimentation and analyse the informational effects in a model with buyers and sellers in contrast to the one sided experimentation problems we find that equilibrium experimentation often exceeds the pareto optimal level in two sided models the first model we consider is a dynamic duopoly in continuous time with homogeneous buyers two firms with differentiated products engage in price competition over time one product has a known value while the other is new and its true value is initially uncertain to all the parties in the model the value of the product is determined by the quality of the match between consumer preferences and product characteristics additional information is acquired only through repeat purchases in each period buyers observe a noisy signal of the true value of the product we assume that all signals are publicly observable and that all uncertainty is about a common value component with this assumption all buyers and sellers condition their behaviour on the same information and we can abstract from individual differences in past observations this is justified in economic situations where public data on other buyers choices is available and informative for example when choosing among providers of communication or transportation services such as mail delivery firms or airlines it is reasonable to rely on consumer reports and other published data in addition to one s private experience we also show that our model has an alternative interpretation as one where a flow of buyers make a once and

price dispersion and learning in a dynamic differentiated goods duopoly we study the evolution of prices set by duopolists who are uncertain about the perceived degree of product differentiation customers sometimes view the products as close substitutes sometimes as highly differentiated as the informativeness of the quantities sold increases with the price differential there is scope for active learning by firms when information has low value to the firms they charge the same price as would be set by myopic players and there is no price dispersion when firms value information more highly on the other hand they actively learn by creating price dispersion such price dispersion arises in a cyclical fashion and is most likely to be observed when the firms environment changes sufficiently often but not too frequently firms payoffs are higher when they use correlated pricing strategies contrary to what one might expect such coordination need not hurt consumers provided they are sufficiently impatient

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

limited farsightedness in network formation pairwise stability jackson and wolinsky 1996 is the standard stability concept in network formation it assumes myopic behavior of the agents in the sense that they do not forecast how others might react to their actions assuming that agents are perfectly farsighted related stability concepts have been proposed we design a simple network formation experiment to test these extreme theories but find evidence against both of them the subjects are consistent with an intermediate rule of behavior which we interpret as a form of limited farsightedness on aggregate the selection among multiple pairwise stable networks and the performance of farsighted stability crucially depends on the level of farsightedness needed to sustain them and not on efficiency or cooperative considerations individual behavior analysis corroborates this interpretation and suggests in general a low level of farsightedness around two steps on the part of the agents

why are similar workers paid differently the role of social networks abstract we provide a matching model where identical workers are embedded in ex ante identical social networks job arrival rate is endogenous and wages are bargained we study the evolution of networks over time and characterize the equilibrium distribution of unemployment rates across networks within our framework wage dispersion arises endogenously as the consequence of the dynamics of networks firms strategies and wage bargaining we show that networks induce new search externalities which shape the dynamics of the labor market our endogenous framework allows us to quantify these effects

markets for water rights under environmental constraints abstract the cumulative impact of pollutants on water quality at a given location along a river is a function of prior loadings as well as pollution and surface flows at that particular site the question of whether it is possible to maintain water quality under alternative mechanisms for allocating surface water and pollution rights is addressed we model the optimal allocation of surface water and pollution rights along a river with water quality constraints due to cumulative effects the shadow values of water and pollution rights are contingent on location it is shown that a nash equilibrium in a market for tradable surface water rights in conjunction with a market for pollution damages implements the optimal solution the market supports location specific prices for both consumptive water rights and pollution damages

designing organizations for trading pollution rights regulators and academicians have recently become interested in using a marketable permits program as a new way to control aggregate pollution emissions our research focuses on choosing a permit trading mechanism that is both economically efficient and politically viable we consider an organized trading process and a revenue neutral auction both of which involve an initial allocation of permits based on past history each is tested in a competitive and in a non competitive environment to determine which mechanism performs best the results of our research suggest that overall the organized trading process outperforms the revenue neutral auction

allocating resources in an uncertain world water management and endangered species instream flows may be essential in protecting aquatic species that are threatened or endangered an economic model of the optimal allocation of water under pure uncertainty is developed with particular attention paid to the situation when a species characterized by critical depensation is affected by instream flows we adopt the notion of pure uncertainty that frank knight and daniel ellsberg intended which applies when decision makers cannot reduce their uncertainty to a unique probability distribution following recent work by hansen sargent and others we employ robust control as a way to deal with this problem copyright 2008 oxford university press

on vertical relations and the timing of technology adoption we study the timing of new technology adoption in markets with input outsourcing and thus with vertical relations we find that technology adoption can take place earlier when firms engage in input outsourcing than when they produce the input in house hence the presence of vertical relations can accelerate the adoption of a new technology we also find that particular features of a vertically related market such as the distribution of bargaining power and the contract type through which trading is conducted can crucially affect the speed of technology adoption

information acquisition and exchange in social networks a central feature of social networks is information sharing the internet and related computing technologies shape the relative costs of private information acquisition and forming links with others this article presents an experiment on the effects of changing costs we find that a decline in relative costs of linking makes private investments more dispersed and gives rise to denser social networks aggregate investment falls but individuals access to investment remains stable due to increased networking the overall effect is an increase in individual utility and aggregate welfare

a trading ratio system for trading water pollution discharge permits abstract the fact that water flows to the lowest level uni directionally is a very specific and useful property of water by utilizing this property we design a trading ratio system trs of tradable discharge permits for water pollution control such a trading ratio system has three main characteristics 1 the zonal effluent cap is set by taking into account the water pollutant loads transferred from the upstream zones 2 the trading ratios are set equal to the exogenous transfer coefficients among zones and 3 permits are freely tradable among dischargers according to the trading ratios this paper shows that the trs can take care of the location effect of a discharge and can achieve the predetermined standards of environmental quality at minimum aggregate abatement costs problems with hot spots and free riding can be avoided and the burdens on both dischargers and the environmental authority should be relatively light

coalition formation as a dynamic process abstract we study coalition formation as an ongoing dynamic process with payoffs generated as coalitions form disintegrate or regroup a process of coalition formation pcf is an equilibrium if a coalitional move to some other state can be justified by the expectation of higher future value compared to inaction this future value in turn is endogenous it depends on coalitional movements at each node we study existence of equilibrium pcfs we connect deterministic equilibrium pcfs with unique absorbing state to the core and equilibrium pcfs with multiple absorbing states to the largest consistent set in addition we study cyclical as well as stochastic equilibrium pcfs

investment timing and learning externalities abstract we study a duopoly model of investment in which each player learns about the quality of a common value project by observing some public background information and possibly the experience of his rival investment costs are private information and the background signal takes the form of a poisson process conditional on the quality of the project being low the resulting attrition game has a unique symmetric equilibrium which depends on initial public beliefs we determine the impact of changes in the cost and signal distributions on investment timing and how equilibrium is affected when a first mover advantage is introduced

market power in water markets abstract we model market power in water markets as multi market cournot competition with a river structure suppliers are connected through water balances which imposes resource constraints and they are connected to heterogeneous water users via a water delivery infrastructure our model captures a wide range of specific water market structures we establish conditions for existence of an equilibrium and we assess the effects of market power on water extraction delivery and water prices although the monopoly case is similar to standard economic theory three other specific water market structures illustrate that standard intuition has to be revisited

ex post regret and the decentralized sharing of information abstract firms reveal private information about the value of investment through their investment decisions as a consequence they may have ex post regret once they see other firms investments we define a notion of rational expectations equilibrium for games which imposes a no regret property in this equilibrium all firms make the same investment decision but despite the absence of ex post regret the investment herd can be inefficient in addition equilibrium might not exist we introduce a notion of probabilistic existence and identify conditions under which if the number of firms is large enough information comes out so that investment herds are first best efficient with high probability and equilibrium exists with high probability journal of economic literatureclassification numbers c7 d8

taking the road less traveled by does conversation eradicate pernicious cascades abstract we offer a model in which sequences of individuals often converge upon poor decisions and are prone to fads despite communication of the payoff outcomes from past choices this reflects both direct and indirect action based information externalities in contrast with previous cascades literature cascades here are spontaneously dislodged and in general have a probability less than one of lasting forever furthermore the ability of individuals to communicate can reduce average decision accuracy and welfare

the optimal size of a permit market regulating the emissions of non uniformly mixed pollutants with a permit market carries the risk of hot spot formation which can be reduced by dividing the regulation area into trading zones the trading zone approach has been extensively discussed for the full information case we consider incomplete information concerning the emitters abatement costs their locations and pollution dispersion we derive the optimal number of trading zones and the optimal number of permits per zone and analyze under which conditions a system of independent trading zones is superior to other policy measures our results show that appropriately sized permit markets are well suited to regulating non uniformly mixed pollutants under informational constraints if firms are not too heterogeneous only for substantial heterogeneity and a highly non linear damage function can it be optimal to use command and control strategies

job contact networks abstract many workers hear about or obtain their jobs through friends and relatives the aim of this paper is twofold first we relate both individual and aggregate labor market outcomes to the network structure of personal contacts second we study strategic network formation to this purpose we develop a model specifying at the individual level both the decision to form contacts with other agents and the process by which information about jobs is obtained and transmitted we show that equilibrium networks always exist and that only moderate levels of network asymmetry can be sustained at equilibrium also we establish a general non monotonicity result on information flow and unemployment with respect to network size in symmetric networks

bayesian learning in social networks we study the perfect bayesian equilibrium of a sequential learning model over a general social network each individual receives a signal about the underlying state of the world observes the past actions of a stochastically generated neighbourhood of individuals and chooses one of two possible actions the stochastic process generating the neighbourhoods defines the network topology we characterize pure strategy equilibria for arbitrary stochastic and deterministic social networks and characterize the conditions under which there will be asymptotic learning convergence in probability to the right action as the social network becomes large we show that when private beliefs are unbounded meaning that the implied likelihood ratios are unbounded there will be asymptotic learning as long as there is some minimal amount of expansion in observations we also characterize conditions under which there will be asymptotic learning when private beliefs are bounded

the evolution of free trade networks abstract this paper considers the evolutionary dynamics of a free trade agreement fta network formation game among n countries we first explore the static model introduced by goyal and joshi 2006 and precisely characterize the set of pairwise stable fta networks then we develop a dynamic model under random perturbations and identify long run outcomes to remove prediction uncertainty inherited from static analysis the results show that both partial free trade and global free trade will result when there are only three countries however when more countries are involved only the complete fta network emerges

financial regulations and bank credit to the real economy we present a new agent based model focusing on the linkage between the interbank market and the real economy with a stylised central bank acting as lender of last resort using this model we address the tradeoff between stability and economic performance for different structures of the interbank market we also explore the efficacy of recent regulatory reforms using our richer model our results suggest that the effects of regulatory leverage ratios on the banking sector s performance can vary in a complex and non monotonic way with the state of the economy the degree of connectivity of the interbank market and the amount of information available to market participants on bank risks

investment as a process of search this paper analyzes optimal capital accumulation in the face of structural uncertainty in which the firm does not fully know its own profit function and can discover it only through further investment it is shown that under structural uncertainty capital accumulation is gradual even when adjustment costs are linear and not convex it is further shown that structural uncertainty creates an incentive to market research the paper also presents an example of structural uncertainty in which an additional price uncertainty has a negative effect on investment contrary to the standard models

investment under uncertainty irreversibility and the arrival of information over time in this paper we consider a risk neutral competitive firm which is uncertain about the true state of demand we build upon arrow by demonstrating that the irreversibility of investment in physical capital together with the anticipation of receiving information and of learning the state of demand lead to 1 cautious investment behaviour and hence to lower investment levels than otherwise since the firm cannot disinvest if market conditions turn out to be less favourable than currently anticipated 2 a time varying risk premium or marginal adjustment cost which is shown to arise endogenously and to be positively related to the investment level and to the anticipation of greater information in the sense of blackwell 1951 1953 3 a gradual adjustment of the capital stock to the desired level defined as the optimal capital stock corresponding to the true state of demand

social learning and delay in a dynamic model of price competition abstract this paper studies dynamic price competition between two firms selling differentiated durable goods to two buyers whose valuations of the two goods depend on their own private type as well as that of the other buyer we derive a key intertemporal property of the equilibrium prices and construct an equilibrium based on this property we show that social learning reduces the equilibrium prices in the sense that when the buyers are more interdependent and hence have a stronger incentive to wait and see the firms respond by lowering their period 1 prices interestingly we find that this response by the firms along with the intertemporal property of the equilibrium prices implies that buyers delay their decisions less often when they become more interdependent

experimentation imitation and stochastic stability abstract do boundedly rational agents repeatedly playing a symmetric game with a unique symmetric equilibrium learn over time to play it in this paper we model the dynamic interaction of two types of such agents experimenters and imitators whose behavior is characterized by simple rules of thumb we find that the stochastic process describing their play isstable in the large it converges globally and with probability one to a compact neighborhood of the equilibrium however its local behavior near the equilibrium depends in interesting ways on the details of the model journal of economic literatureclassification number d83

goodwill hunting and profit sharing decision making in a newspaper chain a generalised equilibrium solution to the stochastic two echelon newsvendor problem is achievable when formulated in the context of some cooperation and coordination between the primal retailer and dual manufacturer operators we build on previous work detailing this equilibrium solution and apply it to the newspaper business the solution incorporates changes in variability encountered due to promotional activity which extends the efficient frontier we also consider consequences for profit and goodwill costs of identifying an equilibrium solution when additional income is generated from a source outside of the supply chain such as advertising we generalise to the supply chain network where there is some knowledge of demand or supply distributions further up or down the supply chain we find that the primal dual formulation and equilibrium solution apply to interactions between components of supply chain networks and illustrate with the transition to the direct distribution of newspapers

group formation in risk sharing arrangements we study informal insurance within communities explicitly recognizing the possibility that subgroups of individuals may destabilize insurance arrangements among the larger group we therefore consider self enforcing risk sharing agreements that are robust not only to single person deviations but also to potential deviations by subgroups however such deviations must be credible in the sense that the subgroup must pass exactly the same test that we apply to the entire group it must itself employ some self enforcing risk sharing agreement we observe that the stability of subgroups is inimical to the stability of the group as a whole two surprising consequences of this analysis are that stable groups have uniformly bounded size a result in sharp contrast to the individual deviation problem and that the degree of risk sharing in a community is generally non monotonic in the level of uncertainty or need for insurance in the community

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

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

learning and information aggregation in an exit game we analyze information aggregation in a stopping game with uncertain common payos players learn from their own private experiences as well as by observing the actions of other players we give a full characterization of the symmetric mixed strategy equilibrium and show that information aggregates in randomly occurring exit waves observational learning induces the players to stay in the game longer the equilibria display aggregate randomness even for large numbers of players

information revelation and strategic delay in a model of investment we model investment as an n player game with a pure informational externality each player s payoff depends only on his own action and the state of nature however because a player s action reveals his private information players wait to see what other players will do equilibrium is inefficient because delay is costly and information is imperfectly revealed we characterize the unique symmetric perfect bayesian equilibrium and study the robustness of delay which turns out to be sensitive to the reaction speed and the number of players we establish the following results i when the period length is very short the game ends very quickly and there is a form of herding or informational cascade which results in a collapse of investment ii as the period length increases the possibility of herding disappears iii as the number of players increases the rate of investment and the information flow are eventually independent of the number of players adding more players simply increases the number who delay iv in the limit the time profile of investment is extreme a period of low investment followed either by an investment surge or a collapse

persistence and reversal in herd behavior theory and application to the decision to go public we model rational herd behavior when the underlying value changes over time with payoffs that are either dependent or independent of the underlying value we show that herding does not last forever and is not monotone in signal quality high correlation among agents actions does not necessarily imply herding this suggests alternative empirical methods are needed to detect herding the model has many applications including the ipo decision in which payoffs are state dependent the model implies that the decision to go public is more likely associated with herding than the decision to delay an ipo copyright 2002 oxford university press

on the formation of interaction networks in social coordination games there are many situations where two interacting individuals can benefit from coordinating their actions we examine the endogenous choice of partners in such social coordination games and the implications for resulting play we model the interaction pattern as a network where individuals periodically have the discretion to add or sever links to other players with such endogenous interaction patterns we see multiple stochastically stable states of play including some that involve play of equilibria in the coordination game that are neither efficient nor risk dominant thus the endogenous network structure not only has implications for the interaction pattern that emerges but it also has a significant impact on the play in the coordination game relative to what would arise if the same interaction network were exogenous

third country effects on the formation of free trade agreements the recent proliferation of free trade agreements ftas has resulted in an increasingly complex network of preferential trading relationships the economics literature has generally examined the formation of ftas as a function of the participating countries economic characteristics alone in this paper we show both theoretically and empirically that the decision to enter into an fta is also crucially dependent on the participating countries existing fta relationships with third countries accounting for the interdependence of ftas helps to explain a significant fraction of fta formations that would not otherwise be predicted by countries economic characteristics

why do people invest in personal pension plans the aim of this article is to identify the variables affecting the decision to make contributions to personal pension plans and the amount of such contributions for this purpose we specify and estimate a tobit model for a sample based on the 1995 personal income taxpayers panel prepared by the institute of fiscal studies spanish ministry of economy and finance formed by 3041 taxpayers of whom 358 made contributions to pension plans our results suggest that individuals decide to invest in pension plans on complex grounds combining the wish to benefit from tax savings and to ensure they will receive supplementary income upon retirement

free trade networks abstract the paper examines the formation of free trade agreements ftas as a network formation game we consider an n country model in which possibly asymmetric countries trade differentiated industrial commodities we show that if all countries are symmetric the complete fta network is pairwise stable and it is the unique stable network if industrial commodities are not highly substitutable we also compare ftas and customs unions cus as to which of these two regimes facilitates global trade liberalization noticing that unlike cus each signatory of an fta can have another fta without consent of other member countries

networked relationships in the e mid interbank market a trading model with memory interbank markets are fundamental for bank liquidity management in this paper we introduce a model of interbank trading with memory our model reproduces features of preferential trading patterns in the e mid market recently empirically observed through the method of statistically validated networks the memory mechanism is used to introduce a proxy of trust in the model the key idea is that a lender having lent many times to a borrower in the past is more likely to lend to that borrower again in the future than to other borrowers with which the lender has never or has in frequently interacted the core of the model depends on only one parameter representing the initial attractiveness of all the banks as borrowers model outcomes and real data are compared through a variety of measures that describe the structure and properties of trading networks including number of statistically validated links bidirectional links and 3 motifs refinements of the pairing method are also proposed in order to capture finite memory and reciprocity in the model the model is implemented within the mason framework in java

the formation of financial networks modern banking systems are highly interconnected despite various benefits linkages between banks carry the risk of contagion in this article i investigate whether banks can commit ex ante to mutually insure each other when there is contagion risk in the financial system i model banks decisions to share this risk through bilateral agreements a financial network that allows losses to be shared among various counterparties arises endogenously i characterize the probability of systemic risk defined as the event that contagion occurs conditional on one bank failing in equilibrium interbank networks i show that there exist equilibria in which contagion does not occur

appropriative water rights and the efficient allocation of resources this paper investigates the allocative efficiency of the appropriative system of water rights within the context of a simplified model of a water using industry at a long run competitive equilibrium for the industry and with a prohibition on the transfer of water rights among firms it is shown that 1 senior appropriators claim and use more water than junior appropriators 2 senior appropriators bear less risk than junior appropriators 3 the allocation of water and diversion capacitie 6among firms is inefficient being dominated by an equal sharing among firms the equal sharing allocation which is pareto optimal when diversion capacities are supplied by a competitive leasing industry can be achieved under the appropriative system if there are competitive markets in water rights and in leases for the use of diversion capacities an application of the coase theorem