bilateral bargaining with externalities this paper provides an analysis of a non cooperative pairwise bargaining game between agents in a network we establish that there exists an equilibrium that generates a coalitional bargaining division of the reduced surplus that arises as a result of externalities between agents that is we provide a non cooperative justification for a cooperative division of a non cooperative surplus the resulting division is related to the myerson shapley value with properties that are particularly useful and tractable in applications we demonstrate this by examining buyer seller networks and vertical foreclosure

the behavior of prices in the nikkei spot and futures market abstract we examine the relation between the prices of japanese stocks traded on the tokyo stock exchange tse as reflected in the nikkei stock average nsa stock index and the prices of the nsa futures contract traded on the singapore international monetary exchange simex since the inception of trading in september 1986 the nsa futures contract has generally sold at a discount relative to its theoretical value trading restrictions and transaction costs may explain some of this mispricing which has been declining over time as in the u s markets

ecosystem service valuation for national accounting a reply to obst hein and edens 2016 while recent experimental frameworks for national ecosystem service accounting have shown substantial progress in our view some crucial methodological issues remain that deserve further consideration before setting final standards in response to the landmark work of obst et al environ resour econ 64 1 23 2016 doi 10 1007 s10640 015 9921 1 we provide arguments with regard to the suitability of particular valuation approaches generally we agree that respective valuation methods need to produce values that are consistent with national accounting standards such as representing exchange values however we disagree with their conclusions regarding specific valuation techniques firstly the circumstance that methods used for estimating shadow prices can also be used to derive consumer surplus does not justify the general exclusion of all shadow pricing methods for valuation of ecosystem services for national accounts especially for public ecosystem services secondly that preference based methods can also be used to assess welfare changes does not imply that cost based methods are generally better suited for ecosystem accounting to the contrary we see an essential need for preference information in accounting contexts thirdly that accounting standards use a written down replacement cost approach does not mean ecosystem accounting requires to employ a replacement cost approach to the contrary we argue that assessing ecosystem degradation through restoration costs would be in line with writing down depreciation but we also point to its limits

price movements and price discovery in futures and cash markets r isk transfer and price discovery are two of the major contributions of futures markets to the organization of economic activity working 1962 evans 1978 p 80 and silber 1981 risk transfer refers to hedgers using futures contracts to shift price risk to others price discovery refers to the use of futures prices for pricing cash market transactions working 1948 wiese 1978 p 87 and lake 1978 p 161 the significance of both contributions depends upon a close relationship between the prices of futures contracts and cash commodities this paper examines the characteristics of price movements in cash or spot markets and futures markets for storable commodities section ii presents an analytical model of simultaneous price dynamics which suggests that over short intervals of time the correlation of price changes is a function of the elasticity of arbitrage between the physical commodity and its counterpart futures contract greater elasticity fosters more highly correlated price changes and thereby facilitates the risk transfer function the elasticity of supply of arbitrage services is constrained by among other things storage and transaction costs thus futures contracts will not in general provide perfect risk transfer facilities over short time horizons the essence of the price discovery function of futures markets hinges on whether new information is reflected first in changed futures prices or in changed cash prices hoffman 1932 pp 258259 the model in section ii provides a framework for analyzing whether one market is dominant in terms of information flows and price discovery in section iii we develop a model based on section ii which is appropriate for estimating the lead lag relationship between cash prices and futures prices section iv presents empirical estimates of the parameters of the model for seven different storable commodities wheat corn oats frozen orange juice concentrates copper gold and silver the cost of arbitrage between cash and futures differs across these commodities for this reason we are not surprised to find inter commodity differences in the correlation of short run price changes and in the substitutability of futures contracts for cash market positions with respect to the price discovery function of futures markets we find that while futures markets dominate cash markets cash prices do not merely echo futures prices there are reverse information flows from cash markets to futures markets as well

vector autoregression or simultaneous equations model the intraday relationship between index arbitrage and market volatility abstract we conduct simulations to compare the vector autoregression var and simultaneous equations models sem for examining temporal relationships among arbitrage spreads spot price volatility and futures price volatility contrary to koch 1993 we find that the var model can better reveal the underlying process and that sem can be misleading and may yield unreliable inferences

organizational design and technology choice under intrafirm bargaining comment the authors consider a wide number of applications of an intrafirm bargaining game within organizations where employees and the firm engage in wage negotiations under their presumption that contracts cannot bind employees to the organization the resulting stable wage and profit profiles give rise to an objective function for the firm that places weight on inframarginal profits in an economically significant manner the authors in turn employ this methodology to explore applications of organizational design hiring and capital decisions training and cross training the importance of labor and asset specificity managerial hierarchies preferences for unionization responses to competition and internal capital budgeting copyright 1996 by american economic association

bargaining foundations of shapley value1 a transferable utility economy in which each agent holds a resource which can be used in combination with the resources of other agents to generate value according to the characteristic function v is studied using a dynamic model of bargaining the main theorem establishes that the payoffs associated with efficient equilibria converge to the agents shapley values as the time between periods of the dynamic game goes to zero in addition it is demonstrated that an efficient equilibrium exists and is unique when an additivity condition is satisfied to demonstrate the sensitivity of the solution to the institutional detail we modify the model to allow for partnerships and show that the shapley value is no longer achieved

on governing multilateral transactions with bilateral contracts bilateral contracts while neither negotiated nor enforced in an integrated way are nevertheless often interrelated both economically and strategically owing to production or consumption complementarities and to asymmetric information a set of bilateral contracts forms a mechanism with special properties this mechanism forms a contract equilibrium if there is no joint incentive for a supplier and any individual customer unilaterally to alter the terms of their contract if agents preferences are risk neutral in money income and if their private information is independent then there exists a contract equilibrium that implements efficient transactions if in addition preferences are strictly concave and differentiable in goods and services and technologically feasible sets are suitably convex then this equilibrium is essentially unique

intra firm bargaining under non binding contracts we present a new methodology for studying the problem of intra firm bargaining based on the notion that contracts cannot commit the firm and its agents to wages and employment we develop and analyse a general non cooperative multilateral bargaining framework between the firm and its employees and consider outcomes which are immune to renegotiations by any party equilibrium firm profits are characterizable as both a weighted average of a neo classical non bargaining firm s profits and a generalization of shapley value for a corresponding cooperative game furthermore the resulting payoffs induce economically significant distortions in the firm s input and organizational design decisions

bargaining and value we present and analyze a model of noncooperative bargaining among n participants applied to situations describable as games in coalitional form this leads to a unified solution theory for such games that has as special cases the shapley value in the transferable utility tu case the nash bargaining solution in the pure bargaining case and the recently introduced maschler owen consistent value in the general nontransferable utility ntu case moreover we show that any variation in a certain class of our bargaining procedure which generates the shapley value in the tu setup must yield the consistent value in the general ntu setup

lag length selection and tests of granger causality between money and income one of the most widely accepred relationships in macroeconomics is the positive relationship between the rate of growth of the money supply and the rate of growth of income a diversity of opinion arises however with the attempt to identify a causal relationship between these variables while friedman and schwartz 1963 initiated the empirical investigation of money income causality sims 1972 made the most significant contribution to this literature with a practical application of the criterion developed by granger 1969 for identifying a causal relationship since the appearance of sims s approach and an alternative one advanced by sargent 1976 many researchers have applied these techniques to the investigation of the causal relationship between money and income l with two exceptions hsiao 1981 and mcmillin and fackler 1984 these researchers have arbitrarily chosen the lengths of their distributed lags the purpose of this paper is to test for granger causality between money and income this paper differs from previous work in that considerably more attention is focused on the effect of the lag specification on the test results in particular we investigate the extent to which rules of thumb arbitrary lag specifications and

reexamining intraday simultaneity in stock index futures markets abstract this note examines three empirical examples involving intraday dynamic relationships associated with stock index futures markets researchers often employ a vector autoregressive var model to analyze such high frequency transactions data while such a model can provide useful information regarding the nature of causal priority inherent in the data it is not the proper model to investigate the structural relationships of interest because it omits the contemporaneous interaction on the other hand a var model specification which is altered to incorporate simultaneity may enable the data to reveal the structural relationships of interest

a transactions data test of stock index futures market efficiency and index arbitrage profitability this paper investigates the efficiency of the market for stock index futures and the profitability of index arbitrage for the chicago board of trade s major market index contracts the spot value of the index is computed with transactions prices for the component shares of the index obtained from the fitch database the tests account for transaction costs execution lags and the uptick rule for short sales of stocks results indicate that the size and frequency of boundary violations are substantially smaller than those reported by earlier studies and have declined sharply with time index arbitrage is a strategy whereby institutions brokerage houses or other large investors seek to profit from the spread between prices in the spot and futures markets for stock indices for example an investor might purchase predetermined baskets of stocks on the floor of the new york stock exchange and simultaneously sell a related index futures contract on the floor of the chicago board of trade hoping to profit from the price differences on the two exchanges computer programs constantly monitor stock and futures prices and automatically execute buy and sell orders when it appears that a profit is possible stock index futures can be priced by a simple arbitrage argument if the dividends paid by the underlying basket of shares and interest rates are nonstochastic markets are perfect and there are no taxes the pricing equation is

bidding for the surplus a non cooperative approach to the shapley value abstract we propose a simple mechanism to determine how the surplus generated by cooperation is to be shared in zero monotonic environments with transferable utility the mechanism consists of a bidding stage followed by a proposal stage we show that the subgame perfect equilibrium outcomes of this mechanism coincide with the vector of the shapley value payoffs we extend our results to implement the weighted shapley values finally we generalize our mechanism to handle arbitrary transferable utility environments the modified mechanism generates an efficient coalition structure and implements the shapley values of the super additive cover of the environment journal of economic literature classification numbers c71 c72

the non existence of pairwise proof equilibrium abstract private bilateral contracting between a supplier and competing customers admits multiple equilibria we show that requiring equilibrium to be pairwise proof immune to bilateral deviations by the supplier and any customer can imply non existence of equilibrium in normal environments

cyclical delay in bargaining with externalities externalities between buyers are shown to induce delays in negotiations between a seller and several buyers delays arise in a perfect and complete information setting with random matching even when there is no deadline while with a deadline we identify delays both for positive and negative externalities without a deadline we find that 1 when externalities are positive there exists no spne in pure strategies with bounded recall that exhibits delay 2 when externalities are negative it may happen that all spne with bounded recall have the property that long periods of waiting alternate with short periods of activity this is the cyclical delay phenomenon

the dynamics of stock index and stock index futures returns in rational efficiently functioning markets the returns on stock index and stock index futures contracts should be perfectly contemporaneously correlated this study investigates the time series properties of 5 minute intraday returns of stock index and stock index futures contracts and finds that sp however the effect is not completely unidirectional with lagged stock index returns having a mild positive predictive impact on futures returns

the temporal price relationship between s p 500 futures and the s p 500 index this paper empirically examines the intraday price relationship between s p 500 futures and the s p 500 index using minute to minute data three stage least squares regression is used to estimate lead and lag relationships with estimates for expiration days of the s p 500 futures compared with estimates for days prior to expiration the results suggest that futures price movements consistently lead index movements by twenty to forty five minutes while movements in the index rarely affect futures beyond one minute

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

a further analysis of the lead lag relationship between the cash market and stock index futures market the intraday lead lag relation between returns of the major market cash index and returns of the major market index futures and s p 500 futures is investigated empirical results show strong evidence that the futures leads the cash index and weak evidence that the cash index leads the futures the asymmetric lead lag relation holds between the futures and all component stocks including those that trade in almost every five minute interval evidence indicates that when more stocks move together market wide information the futures leads the cash index to a greater degree this suggests that the futures market is the main source of market wide information article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

upstream horizontal mergers vertical contracts and bargaining abstract we study horizontal mergers in the upstream sectors of vertically related industries when bargaining is present and contract types are endogenous we demonstrate that the contract types used can have significant implications for the equilibrium market structure and vice versa when trading takes place through two part tariff contracts merger incentives are absent however when the downstream firms are powerful merger incentives are restored since the merger leads then either to the exclusive or to the partial use of wholesale price contracts finally we show that whenever a merger occurs it is welfare detrimental

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

bilateral monopolies and incentives for merger the paper presents a model of duopoly in which firms acquire inputs through bilateral monopoly relations with suppliers it combines a bargaining model with a duopoly model to examine how input pri

strategic spin offs of input divisions abstract when a downstream producer enters backward into the input market a helping the rivals effect exists such entry hurts the firm s downstream business as it increases upstream competition and thus benefits its rival downstream firms this negative externality prevents the newly created upstream unit from expanding a spin off enables the firm to credibly expand in the input market thereby forcing its upstream competitors to behave less aggressively spin offs occur in equilibrium if and only if the number of downstream firms exceeds a threshold level when there is more than one integrated firm a spin off by a firm can trigger spin offs by others that would not occur otherwise

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

evolution in dynamic linkages across daily national stock indexes abstract this article investigates how dynamic linkages among the daily rates of return of eight national stock indexes have evolved since 1972 a dynamic simultaneous equations model is estimated to describe the contemporaneous and lead lag relationships across national equity markets over three different years 1972 1980 and 1987 results reveal growing market interdependence within the same geographical region over time while there are many significant intermarket relationships within the same 24 hour period there are few significant lagged responses across markets beyond 24 hours this suggests a high degree of international market efficiency furthermore japan s market influence has been growing to rival that of the usa

downstream mergers and producer s capacity choice why bake a larger pie when getting a smaller slice in this article the effect of downstream horizontal mergers on the upstream producer s capacity choice was studied contrary to conventional wisdom i find a nonmonotonic relationship horizontal mergers induce a higher upstream capacity if the cost of capacity is low and a lower upstream capacity if this cost is high this result is explained by decomposing the total effect into two competing effects a change in holdup and a change in bargaining erosion

the welfare effects of bundling in multichannel television markets we measure how the bundling of television channels affects short run welfare we estimate an industry model of viewership demand pricing bundling and input market bargaining using data on ratings purchases prices bundles and input costs we conduct simulations of a la carte policies that require distributors to offer individual channels for sale to consumers we estimate that negotiated input costs rise by 103 0 percent under a la carte these higher input costs offset consumer benefits from purchasing individual channels mean consumer and total surplus change by an estimated 5 4 to 0 2 percent and 1 7 to 6 0 percent respectively jel d12 l11 l51 l82 m31

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

intraday relationships among index arbitrage spot and futures price volatility and spot market volume a transactions data test abstract this paper examines intraday temporal relationships among arbitrage spreads cash and futures price volatility and cash trading volume using transactions data for the major market index futures contracts and the component stocks of the index results indicate that changes in the spread have a significant impact on cash and futures price volatility as well as on cash trading volume the impact of the spread however is attenuated by the short sale restriction in the cash market contrary to popular beliefs a more volatile market leads to subsequent decreases in the spread probably because of increases in the supply of arbitrage services or faster price adjustments

intraday volatility in the stock index and stock index futures markets we examine the intraday relationship between returns and returns volatility in the stock index and stock index futures markets our results indicate a strong intermarket dependence in the volatility of the cash and futures returns price innovations that originate in either the stock or futures markets can predict the future volatility in the other market we show that this relationship persists even during periods in which the dependence in the returns themselves appears to weaken the findings are robust to controlling for potential market frictions such as asynchronous trading in the stock index our results have implications for understanding the pattern of information flows between the two markets article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

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

equilibrium vertical foreclosure the authors formulate a complete but analytically simple equilibrium model of vertical mergers to evaluate the logic of standard vertical foreclosure claims and the criticisms made of those claims the model includes incentives of the integrated firm and unintegrated input suppliers to exclude rivals and the potential holdout problem in this fully specified model vertical foreclosure can emerge in equilibrium copyright 1990 by american economic association

stock index futures does the tail wag the dog the increase in program trading based on a comparatively narrow blue chip stock market barometer the major market index mmi is said to be fueling volatile price swings in the stock market a case of the tail wagging the dog the mmi is a price weighted index of 20 very actively traded stocks 16 of which are included in the dow jones 30 industrials because of its relatively small size the mmi is expected to be more easily arbitragible than other stock index futures contracts basically program trading involves taking a position long or short in a portfolio of stocks comprising the index and simultaneously taking an opposite position in the index futures contracts the objective of the program trade is to create a risk free position that earns a return in excess of the currently available risk free return program trades may move both the futures and the spot market the chain of causality may work as follows 1 investors believe the stock market will rise and they purchase futures contracts in expectation of higher equity values the purchase of the contracts is preferable to the purchase of the underlying stocks because it entails no initial investment and lower transaction costs 2 the rise in futures prices causes an imbalance between the prices of the futures and the underlying index as this premium between futures and index increases it may become profitable to execute a program trade 3 the simultaneous sale of futures and purchase of the underlying index will cause the premium between the futures and index to shrink changes in factors such as interest rates can also affect the equilibrium relation between the index price and the futures price thereby changing the premium or discount between the two markets program traders can take advantage of any change in the spread between the markets it does not matter what causes the change in spreads whether internal factors such as changes in investor expectations or external factors such as interest rate changes all program trading does is to bring cash and futures prices together the program trade may be an essential mechanism that ensures that futures prices and underlying equity prices are efficiently determined and that the hedging effectiveness of the futures contracts is reliable to date most of the literature on the impact of futures trading on the cash market has focused on changes in spot price volatility because of the initiation or cessation of futures trading a common conclusion of these studies is that the futures market has a smoothing effect on the cash market stabilizing the spot price the recent uproar engendered by the triple witching hour and the so called crises at expiration brings into question the smoothing influence that futures have on the underlying index 2 if the market is efficient prices adjust instantaneously to reflect all relevant information and knowledge of such information cannot lead to excess risk adjusted returns the central concept in the efficient market hypothesis is the fair game model 3 a sequence of past returns over time is a fair game if today s price reflects the then available information making it impossible to earn excess risk adjusted returns by trading on that information if the information set today contains all the information known and used by the market participants in the spot market in determining the spot price one of the components of the information set is the previous change in the price of futures contracts 4 does the tail wag the dog the financial press and the sec have answered this question in the affirmative 5 this note investigates the impact of the futures market on the spot market by evaluating the relation between index futures price changes and subsequent spot index price changes in addition we evaluate the degree to which the expiration of the futures contract affects the underlying index

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

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

insurer provider networks in the medical care market i use data on the hospital networks offered by managed care health insurers to estimate the expected division of profits between insurers and providers i include a simple profit maximization framework and an additional effect hospitals that can secure demand without contracting with all insurers e g those most attractive to consumers and those that are capacity constrained may demand high prices that some insurers refuse to pay hospital mergers may also affect price bargaining i estimate that all three types of hospitals capture higher markups than other providers these results provide information on the hospital investment incentives generated by bargaining

incomplete contracts vertical integration and supply assurance this paper extends the analysis of transactions cost models of vertical integration to multilateral settings its main focus is on supply assurance concerns which arise when several downstream firms are competing for inputs in limited supply integration reduces supply assurance concerns for an integrating firm but it may increase them for others therefore to explain the scope of any firm one must consider the overall network of production and distribution relations three fundamental questions are addressed 1 what are the effects of different integration structures 2 what are the determinants of the socially efficient integration structures 3 in what way do equilibrium integration structures differ from socially efficient structures

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

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

a theory of the firm with non binding employment contracts this paper examines an employment relation in which individual workers enjoy some bargaining power vis a vis the firm although they are not unionized the main elements of the situations studied here are that the employment contracts are non binding across periods of production and that the firm has opportunities to replace workers the paper analyzes a dynamic model in which the processes of contracting and recontracting between the firm and its workers are intertwined with the dynamic evolution of the firm s workforce the analysis of the model is somewhat complicated because the employment level is a nondegenerate state variable that evolves over time and is affected by past decisions the main analytical results characterize certain important equilibria the profit maximizing and stationa ry equilibria the unique stationary equilibrium is markedly inefficient it exhibits inefficient over employment and the steady state wages coincide with the workers reservation wage it confirms earlier results derived by stole and zwiebel 1996a b in the context of a static model and shows that they are very robust even when the firm has nearly frictionless hiring opportunities in contrast in the profit maximizing equilibrium the outcome is nearly efficient and the wage exhibits a mark up over the reservation wage

bilateral control with vertical contracts when a manufacturer contracts secretly with competing retailers he is subject to opportunism and linear or non linear tariffs may not allow the manufacturer to maintain monopoly prices to analyse the effects of rpm o brien shaffer 1992 use a concept of contract equilibrium which concentrates on pairwise deviations thereby questioning the robustness of the analysis this paper emphasises the distinction between the contract equilibrium and standard non cooperative concepts we advocate for some caution in the use of the former concept as if overlooks an inexistence problem we then confirm the intuition that rpm can help solve the manufacturer s commitment problem this confirms that o brien shaffer s insight is robust and validates the courts reluctance against rpm

intraday relationships between volatility in s p 500 futures prices and volatility in the s p 500 index abstract this paper examines the intraday relationships between the volatility of s p 500 futures prices and the volatility of the s p 500 index we calculate variance measures for minute to minute price changes on a daily basis and across 30 minute intervals the empirical results indicate that i futures volatility is greater than index volatility ii volatility increased for both futures prices and the index in absolute terms from 1984 through 1986 iii both futures and index volatility increased directly with futures trading volume and iv index volatility was systematically greater during the first 30 minutes of trading each day than at other times granger tests however reveal no systematic pattern of futures volatility leading index volatility or index volatility leading futures volatility