conditional production smoothing in the united kingdom and japan this article investigates the possibility of macroeconomic conditional production smoothing of inventory investment in japan and the uk it is argued that both unconditional and conditional variances and covariances can be useful to interpret the time paths of sales and production after sales and production shocks the vector error correction model of sales and production is estimated by the bivariate garch procedure based on the cointegration relationship between these variables in the two countries the relative magnitude of the conditional variances of sales and production is explained in terms of sales anticipation errors the relative importance of sales and production shocks and serial correlation in sales shocks the relation of how the conditional second moment corresponds to business cycle phases is briefly analyzed

economies of traffic density in the deregulated airline industry this article estimates a structural model of competition among hub and spoke airlines in order to measure the strength of economies of traffic density on individual route segments we find that economies of density were strong during the sample period fourth quarter 1985 stronger than previous estimates by douglas caves laurits christensen and michael tretheway derived from traditional cost function methods we also find that the airlines competitive behavior was far from collusive in the markets under study markets requiring a connection at a hub airport our structural model also provides plausible estimates of demand elasticities we use our estimates to provide a cost based rationale for the major changes in the structure of the industry following deregulation for example the increase in airport and industry wide concentration and the increase in competition at the city pair market level and to simulate the effects of a merger of airlines that share a hub

collusion in multiproduct oligopoly games under a finite horizon applying recent results on finitely repeated games to oligopoly theory the author finds that there exists a class of finite horizon output games in which collusion can be achieved as a subgame perfect equilibrium trigger strategies prevent defection from the cooperative outcome by credibly threatening that the defector will be forced to exit the industry for the case of a multiproduct oligopoly it is shown that collusion in one market can be enforced by the threat of punishment in a second market if someone defects even though the two markets are structurally independent the firms make them strategically interdependent through their strategies copyright 1987 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

assessing firm behavior in carve out markets evidence on the impact of carve out policy abstract airlines wanting to cooperatively set prices for their international air travel service must apply to the relevant authorities for antitrust immunity ati while cooperation may yield benefits it can also have anti competitive effects in markets where partners competed prior to receiving ati a carve out policy forbids ati partners from cooperating in markets policymakers believe will be most harmed by anti competitive effects we examine carve out policy applications to three ati partner pairings and find evidence more consistent with cooperative pricing in carve out markets in spite of the policy calling into question the effectiveness of the policy in achieving intended market outcomes

competition in airline networks the case of constant elasticity demands abstract this paper is concerned with the effect of competition in airline hub and spoke networks using constant elasticity demand functions we demonstrate that competition in a single market may generate positive or negative network externalities depending on price elasticities of demand

diversification multi market contact and profitability this paper analyses the relationships between diversification multi market contact and industry profitability it focuses on the link between diversification and multi market contact to show that when diversification establishes or increases the extent to which firms meet in more than one market the effect of such multi market contact is to increase the possibility that collusion emerges as an evolutionary stable strategy as a result multi market contact may increase the potential for tacit collusion and so lead to higher profitability the effects of diversification and multi market contact on the price cost margin and the rate of return to capital are estimated using a specially constructed new database for uk manufacturing industry in 1979 this database provides information on the diversification and multi market contact of 418 firms across 134 manufacturing industries thus linking firm and industry level data the results show a clear positive effect of multi market contact on industry profitability

the economics of international codesharing an analysis of airline alliances abstract international airline alliances allow airlines to coordinate their operations in providing international service this paper analyzes the effect of such alliances on traffic levels fares and welfare in the model the benefits of alliances arise because cooperative pricing of trips by the partners puts downward pressure on fares in the interline city pair markets these are markets where travel on both carriers is necessary the loss of competition in the interhub market which connects the hub cites of the partners generates a countervailing effect tending to raise the fare in that market while the presence of economies of traffic density complicates these impacts by generating cost links across markets simulation analysis shows that the above tendencies typically prevail welfare analysis shows that both consumer and total surplus typically rise following formation of an alliance despite the harm to interhub passengers suggesting that the positive effects of alliances may outweigh any negative impacts

competitive advantage and collusive optima cost differences may often be important in real oligopolies if side payments are impossible the standard cartel objective total industry profits lacks plausibility when costs differ this essay considers plausible alternatives four different technologies for effecting collusion which are essentially identical when costs are equal define sets of possible profits axiomatic bargaining models are used to select unconstrained optima from among these possibilities simple functional forms are employed low cost firms with large shares in cournot equilibrium may have little to gain from collusion if collusion is effective low cost firms will have relatively low estimated conjectural variations

duration measures immunization and utility maximization abstract this paper explores the conditions under which a risk averse investor behaves like an immunizer in choosing the maturity structure of a balance sheet the setting is similar to grove s study in that the liabilities are assumed fixed but differs in the assumed evolution of interest rates m a grove on duration and the optimal maturity structure of the balance sheet bell journal of economics and management science 5 1974 696 709 it transpires that the circumstances under which a risk averse investor behave like an immunizer are not as limited as concluded in grove s study the model thus explains the extensive use of immunization by the business community

the economics of hubs the case of monopoly in this paper we study the optimization problem of an unregulated air carrier which is given the exclusive right to satisfy demand for air travel between any pair of cities it chooses a network of connections and a set of prices to maximize profits thus both network design and prices are endogenous we characterize the solution to this optimization problem when demands and costs are symmetric our main result is that if there are economies of density in the number of individuals travelling between two directly connected cities the optimal network is either a hub of size n 1 or one in which every pair of cities is connected directly

trade costs and multimarket collusion contrary to conventional wisdom this article argues that trade liberalization may facilitate collusion and reduce welfare with the help of a duopoly model in which firms interact repeatedly in multiple markets we first show that if trade costs i e tariffs transport costs and discount factors are not too high efficient cartel agreements necessitate the cross hauling of goods as that entails lower deviation incentives in this setting we then demonstrate that reciprocal trade liberalization always raises total output when trade costs are within a range whose lower bound exceeds a threshold level but may reduce total output and thus be pro collusive when trade costs are below that threshold level

single factor duration models in a discrete general equilibrium framework single factor duration models sfdms for valuing debt securities have gained rapid acceptance by bond practitioners in recent years but slower acceptance by academics in large measure the slower academic acceptance reflects the lack of a rigorously developed underlying economic or financial theoretic base partially as a result some sfdms have undesirable behavioral characteristics foremost among these is that they appear to be inconsistent with accepted general equilibrium conditions this paper has two purposes the first is to construct explicitly the theoretical underpinnings of the model and the second is to develop the conditions under which the model does satisfy general equilibrium conditions this is done in sections i and ii respectively

does multimarket contact facilitate tacit collusion inference on conduct parameters in the airline industry we provide empirical evidence that multimarket contact facilitates tacit collusion among airlines using a flexible model of oligopolistic behavior where conduct parameters are modelled as functions of multimarket contact we find i carriers with little multimarket contact do not cooperate in setting fares whereas carriers serving many markets simultaneously sustain almost perfect coordination ii cross price elasticities play a crucial role in determining the impact of multimarket contact on equilibrium fares iii marginal changes in multimarket contact matter only at low or moderate levels of contact iv assuming firms behave as bertrand nash competitors leads to biased estimates of marginal costs

production smoothing in the linear quadratic inventory model contrary to popular belief the linear quadratic inventory model does not imply that in response to demand shocks output is always less variable than sales when demand shocks are not anticipated and without this assumption it is hard to see why firms should hold inventories in the first place it is shown that output can be more variable than sales even when the only shocks are demand shocks and the inventory target is not a rising function of sales the variance of output will typically exceed that of sales when the firm s marginal cost curve is fairly flat copyright 1994 by royal economic society

aggregate inventory behavior in large european economies abstract inventory fluctuations are known to be an important propagation mechanism for u s business cycles this paper compares the significance of inventory fluctuations in the u s with four other major industrial economies in europe a general model of aggregate inventory demand is specified which seeks to encompass the models presented in recent studies of inventory behavior this model is estimated for the large european economies united kingdom west germany france and italy the preferred models that result from this analysis are compared with the empirical evidence for the u s

rational expectations and the effects of government debt abstract this paper incorporates the effects of government debt into a standard rational expectations macroeconomic model due to limited current information even when the most extreme propositions about fiscal neutrality are true there are output and interest rate effects of unanticipated changes in government debt therefore the observation of a positive correlation between government deficits and output or interest rates does not imply that government bonds are net wealth

the production and inventory behavior of the american automobile industry understanding inventory movements is central to an understanding of business cycles this paper presents an empirical study of the behavior of inventories in the automobile industry it finds that inventory behavior is well explained by the assumption of intertemporal optimization with rational expectations the underlying cost structure appears to have substantial costs of changing production as well as substantial costs of being away from target inventory thelatter being a function of current sales given this cost structure whether inventory behavior is stabilizing or destabilizing depends on the characteristics of the demand process in the automobile industry inventory behavior is destabilizing the variance of production is larger than the variance of sales

impacts of code share alliances on airline cost structure a truncated third order translog estimation abstract the airline industry has undergone significant changes following deregulation more than a decade ago a prominent development in recent years has been the proliferation of airline alliances an important question arises are alliances cost savings or competition reducing this paper addresses the first part of the question however the answer has bearing on the second part as well since results in industrial economics suggest that unless a merger or alliance can substantially reduce costs consumers are unlikely to enjoy lower prices e g farrell j and c shapiro 1990 horizontal mergers an equilibrium analysis american economic review 80 1 107 26 this paper estimates a truncated third order translog cost function using quarterly firm level data of 10 airlines for the period 1994qi to 2001qi using the estimated function we assess whether alliances have any impacts on costs and if so the extent to which the cost structure of airlines are affected it is found that the truncated third order translog is an appropriate specification and alliances do appear to lower costs however while the impacts are statistically significant in economic terms the magnitude appears to be immaterial

evaluating the performance of merger simulation evidence from the u s airline industry abstract this paper uses merger simulations to predict postmerger prices for five airline mergers from the 1980s and compares these predictions with observed postmerger prices i find that standard simulation methods which measure the effect of the change in ownership on unilateral pricing incentives do not generally provide an accurate forecast by incorporating postmerger information into the model i measure the relative importance of other factors that also contributed to the observed price changes the results indicate that the unexplained component of the price change is largely accounted for by supply side effects i conclude that deviations from the assumed model of firm conduct play an important role in accounting for the differences between the predicted and observed price changes this conclusion suggests that the predictive performance of merger simulation would benefit if more flexible models of firm conduct were incorporated into the methodology

entry deterrence and strategic alliances researchers have written extensively on the impact that strategic alliances between airlines have on airfare but little is known of the market entry deterrent impact of strategic alliances using a structural econometric model this paper examines the market entry deterrent impact of codesharing a form of strategic alliance between incumbent carriers in domestic air travel markets we find evidence of market entry deterrence but deterrence impact depends on the specific type of codesharing between market incumbents as well as the identity of the potential entrant we quantify the extent to which market incumbents codesharing influences potential entrants market entry cost and probability of market entry

nonconvex costs and the behavior of inventories this paper explores one possible explanation for the apparent excess volatility of production relative to sales nonconvexities in the technology facing firms it is shown that if firms operate in a region of declining marginal costs then small shifts in demand can cause production to jump substantially estimates for six production to stock industries as well as the automobile industry suggest that all these industries behave as if they were operating in the region of nonconvex costs the results have important implications not only for inventory investment but also for the cyclical behavior of productivity and prices

conditional volatility and the production smoothing hypothesis of inventory investment abstract this paper introduces a conditional second moment approach to the production smoothing hypothesis of inventory investment the multivariate arch technique makes it possible to calculate the time series of the relevant conditional variances and covariances the importance of explaining the production and inventory decision rules in terms of the sales anticipation errors is emphasized the time varying conditional volatility measures suggest that the factors affecting the production and inventory investment are changing over time it is shown that the buffer stock motive can be the source of production smoothing when firms face unanticipated sales changes but the stock adjustment behavior may cause production bunching through the intended change in production if the desired stock of inventories is proportional to anticipated sales and demand shifts are considerably durable

airline code share alliances and their competitive effects abstract code share alliances have become a prominent feature in the competitive landscape of the airline industry however policy makers are extremely hesitant to approve proposed code share alliances when the potential partners route networks have significant overlap the main concern is that an alliance may facilitate price collusion on partners overlapping routes this article shows how policy makers can use a structural econometric framework to quantify the competitive effects of proposed code share alliances where potential alliance partners compete on overlapping routes in the prealliance industry as an example i apply the econometric model to the delta continental northwest alliance this proposed alliance was initially greeted with skepticism by the u s department of transportation owing to the potential partners unprecedented level of route network overlap for the markets considered in my analyses it appears as though the ultimate approval of the alliance by policy makers was justified

multimarket contact and collusive behavior traditional analyses of industrial behavior typically link the exercise of market power in an industry to internalfeatures such as demand conditions concentration and barriers to entry nevertheless some economists have remained concerned that external factors such as contact across markets may also play a significant role in determining the level of competitiveness in any particular industry in this article we examine the effect of multimarket contact on the degree of cooperation that firms can sustain in settings of repeated competition we isolate conditions under which multimarket contact facilitates collusion and show that these collusive gains are achieved through modes of behavior that have been identified in previous empirical studies of multimarketfirms

rational expectations and the smoothing properties of inventories of finished goods abstract this paper formulates and estimates a dynamic rational expectations equilibrium model of inventories of finished goods and employment of labor the view that the primary role of inventories of finished goods is to act as a buffer stock in the face of fluctuating demand is examined both the model and estimation results indicate that this is the case because of differences in the costs involved for firms in changing their inventory stocks and labor force in addition to providing some new evidence on the behavior of inventories of finished goods and employment the paper illustrates a technology for maximum likelihood estimation of structural parameters under the hypothesis of rational expectations

domestic airline alliances and consumer welfare this article investigates the consumer welfare consequences of the recent code share agreement between continental airlines and northwest airlines we develop a discrete choice model based on individual flight characteristics this structural model recognizes that consumers i may have heterogeneous preferences for flight attributes and ii may face different prices for the same flight the empirical methodology also deals with the measurement error problem stemming from the absence of consumer level data on prices the estimation results suggest that whereas the code share agreement did not impact consumers significantly on average it increased the average surplus of connecting passengers but decreased the average surplus of nonstop passengers interestingly the magnitude of our welfare results may be attributed in large part to changes in product characteristics other than prices

the strategic effects of batch processing we study a duopoly game in which firms commit to a batch technology before competing in sales quantities adopting a batch technology requires the quantity produced to equal an integer number of batches and allows sales to be less than production when larger batch sizes lower unit production costs as in the u s airline industry with its economies of density subgame perfect equilibrium sales quantities are unique and more competitive than the cournot equilibrium quantities of a one shot game with continuous total cost functions when larger batch sizes yield higher unit costs equilibrium production can exceed equilibrium sales

inventories and the volatility of production a stylized fact associated with inventory behavior is that the variance of production exceeds the variance of sales this paper presents a model of production decisions with demand uncertainty that incorporates no nnegativity constraints on inventories even with no productivity shocks optimal behavior by the firm is consistent with this stylized fact either if demand exhibits positive serial correlation or if the firm can backlog excess demand the reason is that a demand shock affects both the actual inventory level given unchanged production and the desired level production must replenish the stock and adjust to the new desired level copyright 1987 by american economic association

the economics of airport congestion pricing abstract conventional economic wisdom suggests that congestion pricing would be an appropriate response to cope with the growing congestion levels currently experienced at many airports several characteristics of aviation markets however may make naive congestion prices equal to the value of marginal travel delays a non optimal response this paper develops a model of airport pricing that captures a number of these features the model in particular reflects that 1 airlines typically have market power and are engaged in oligopolistic competition at different sub markets 2 part of external travel delays that aircraft impose are internal to an operator and hence should not be accounted for in congestion tolls and 3 different airports in an international network will typically not be regulated by the same authority we present an analytical treatment for a simple two node network and some numerical results to illustrate our findings some main conclusions are that second best optimal tolls are typically lower than what would be suggested by congestion costs alone and may even be negative and that cooperation between regulators need not be stable but that non cooperation may lead to welfare losses also when compared to a no tolling situation

overcoming incentive constraints by linking decisions consider a bayesian collective decision problem in which the preferences of agents are private information we provide a general demonstration that the utility costs associated with incentive constraints become negligible when the decision problem is linked with a large number of independent copies of itself this is established by defining a mechanism in which agents must budget their representations of preferences so that the frequency of preferences across problems mirrors the underlying distribution of preferences and then arguing that agents incentives are to satisfy their budget by being as truthful as possible we also show that all equilibria of the linking mechanisms converge to the target utility levels the mechanisms do not require transferable utility or interpersonal comparisons of utility and are immune to manipulations by coalitions

the price effects of international airline alliances abstract this paper provides evidence on the effect of international airline alliances on fares the main finding is that alliance partners charge interline fares that are approximately 25 percent below those charged by nonallied carriers according to our theoretical model the main source of this fare reduction is the internalization of a negative externality that arises from the uncoordinated choice of interline sub fares in the absence of an alliance the paper also looks for evidence of an anti competitive alliance effect in the gateway to gateway markets while the point estimates show that an alliance between two previously competitive carriers would raise fares by about 5 percent this effect is not statistically significant

hybrid cooperation agreements in networks the case of the airline industry abstract this paper develops a unified framework to analyze a continuum of hybrid cooperation agreements along two dimensions their degree of revenue sharing scope of alliances and their degree of cost sharing scope of joint ventures the analysis focuses on the air transportation industry distinguishing between interline and interhub markets as economies of traffic density become stronger we find that the socially optimal cooperation agreement moves from full alliance to joint venture in interline markets whereas it moves from joint ventureto merger in interhub markets these results are driven by the tradeoff between a procompetitive effect of alliances in interline markets and an anticompetitive effect in interhub markets along with the efficiency gains associated with joint ventures in interhub markets we also develop an empirical application for intercontinental routes for the period 2010 2016 that identifies a positive impact of deeper degrees of airline cooperation revenue and cost sharing on traffic both in interline and interhub markets therefore the potential anticompetitive effect of deeper alliances in interhub markets is not observed in our sample

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

can the production smoothing model of inventory behavior be saved the production smoothing model of inventory behavior has a long and venerable history and theoretical foundations that seem very strong yet certain overwhelming facts seem not only to defy explanation within the production smoothing framework but actually to argue that the basic idea of production smoothing is all wrong most prominent among these is the fact that the variance of detrended production exceeds the variance of detrended sales this paper first documents the stylized facts then it derives the production smoothing model rigorously and explains how the model can be amended to make it consistent with the facts finally it reviews the theoretical and empirical evidence and tries to draw some tentative conclusions

international airfares in the age of alliances the effects of codesharing and antitrust immunity this paper provides empirical evidence showing the effect of airline cooperation on the interline fares paid by international passengers the analysis focuses on two measures of cooperation codesharing and antitrust immunity and the results show that their partial effects are both negative the presence of codesharing on an international interline itinerary reduces the fare by 8 17 with the exact number depending on the sample used and the estimation method moreover the presence of antitrust immunity reduces the fare by 13 21 codesharing and immunity are substitutes however in the sense that their combined effect is smaller than the sum of their partial effects taking account of this difference which is captured by an interaction variable in the regressions the combined effect ranges between 17 and 30 these results provide strong evidence that airline cooperation in the fare setting process generates substantial benefits for interline passengers

symmetric research joint ventures cooperative substitutes and complements we introduce the concepts of cooperative substitutes and complements and use them to explain when all firms in a research joint venture will choose equal levels of r d we show that the second order conditions for a symmetric optimum take a particularly simple form ruling out both excessive cooperative substitutability and excessive cooperative complementarity and nesting conditions already derived in the literature finally we apply our results to the comparison between cooperative and non cooperative r d and show in an important special case that asymmetric outcomes are only optimal for a very limited range of parameter values

manufacturing stocks expectations risk and co integration the modelling of firms inventory behaviour has been plagued by structural instability and despite a great deal of research effort over recent years little headway has yet been made in producing a structurally stable model of stock levels wallis et al i987 surveyed the main uk models of inventory behaviour and concluded that the tests of predictive failure are particularly powerful when conducted over periods in which data characteristics change and over half the equations we consider are rejected on the basis of their predictive performance in the early i980s this is a surprising result since the poor performance of their predecessors over this period was a prime motivation for the research that has led to the current specifications the similarity in turning points in the forecast errors both for the aggregate stockbuilding equations and for the different categories of stocks suggests the omission of some factor s common to all specifications wallis et al i987 p 144 their analysis was conducted using within sample stability tests and more recent data would undoubtedly find an even higher rejection rate accordingly this paper seeks to identify important omitted components or misspecification in the existing models of inventory behaviour in response to the suggestion in the last sentence of the wallis et al quotation we take as our point of departure a number of recent papers on company sector behaviour which have focused on intertemporal optimisation under rational expectations the seminal work of sargent 1978 on the demand for labour has been followed by a number of studies which seek to treat the firms expectations of future variables in an explicit way this work includes nickell 1 984 and henry and wren lewis i 984 on the labour market and hall et al i986 on the determination of stock levels one common finding amongst these and many other papers is that of a root in the dynamic process under consideration which is close to unity this means that the long run solution for the model is poorly determined and this finding is a cause for some concern recently with the growth of the literature on cointegration see engle and granger 1987 hall i986 this finding takes on an even more serious aspect since a symptom of non cointegration is the lack of a well defined long run solution so the finding of a near unit root may be indicative that earlier researchers were in fact working with sets of variables which failed to cointegrate which would inevitably lead to spurious regression problems in the sense of granger and newbold i 974

the production smoothing model of inventories revisited an error correction specification which nests the linear quadratic production smoothing and stock adjustment models of inventories is estimated on u s seasonally adjusted two digit sic data the restrictions of the general model to the production smoothing specification is accepted for four out of six of the production to stock industries and for total nondurables the estimation results do not suggest any use of inventories to smooth the level of production but there is evidence of smoothing of the rate of change of production for three production to stock industries and for both total nondurables and total durables coefficient estimates may however be biased copyright 1994 by royal economic society

commitment in utility regulation a model of reputation and policy applications abstract this paper builds a dynamic model of utility regulation where a government cannot commit to a time inconsistent policy of not expropriating investment by allowing the government s type to change over time i explore how reputation concerns may generate partial commitment restricting attention to equilibria that are strongly renegotiation proof i show that there is a unique perfect bayesian equilibrium this contains episodes of investment and good behaviour followed by periods of expropriation and non investment i then apply the model to consider how the power of the incentive scheme and decentralization may influence the properties of this equilibrium in the case of the power of incentives the model suggests that price caps may worsen commitment in developing countries but not in developed ones similarly the model suggests that decentralisation is likely to have a significant effect on commitment but that this effect will depend on the general ability of the government to commit overall we conclude that the effect of such policies on commitment will be different across countries depending on the institutional environment

vertical relationships between manufacturers and retailers inference with limited data in this paper different models of vertical relationships between manufacturers and retailers in the supermarket industry are compared demand estimates are used to compute price cost margins for retailers and manufacturers under different supply models when wholesale prices are not observed the purpose is to identify the set of margins compatible with the margins obtained from estimates of cost and to select the model most consistent with the data among non nested competing models the models considered are 1 a simple linear pricing model 2 a vertically integrated model and 3 a variety of alternative strategic supply scenarios that allow for collusion non linear pricing and strategic behaviour with respect to private label products using data on yogurt sold in several stores in a large urban area of the u s the results imply that wholesale prices are close to marginal cost and that retailers have pricing power in the vertical chain this is consistent with non linear pricing by the manufacturers or high bargaining power of the retailers

monopoly competition and information acquisition abstract an incumbent monopolist is uncertain about its linear demand but can acquire public information at a cost we determine how an entry threat affects the firm s information acquisition if returns to scale are constant and the state contingent demands become more dispersed as output increases then entry reduces information acquisition if however either the incumbent or entrant has increasing returns or if the state contingent demands are nonlinear or fail increasing dispersion then entry can increase information finally entry can hurt consumers although entry always increases output it can decrease information consumers sometimes prefer a better informed monopoly to a duopoly

a method for strategic asset liability management with an application to the federal home loan bank of new york strategic asset liability management is a primary concern in today s banking environment in this paper we present a methodology to assist in the process of asset liability selection in a stochastic interest rate environment in our approach a quadratic optimizer is embedded in a simulation model and used to generate patterns of dividends market value and duration of capital for randomly generated interest rate scenarios this approach can be used to formulate test and refine asset liability strategies we present results of applying this methodology to data from the federal home loan bank of new york

immunizing default free bond portfolios with a duration vector dissatisfaction occasionally has been expressed with traditional measures of duration for immunization on conceptual grounds however more elegant duration measures have not been found to be superior to the traditional ones in empirical tests of immunization efficacy under the assumption that the term structure of continuously compounded interest rates can be expressed as a polynomial chambers and carleton 1981 demonstrate that the finite and noninstantaneous return of a default free bond can be expressed as a vector product of a duration vector and a shift vector this study derives immunization strategies from the model and tests them the results of the portfolio tests indicate that the tradi tional duration approach of macaulay provides enhanced immunization relative to matu rity approaches or naive approaches however the duration vector approach produces further improvements

multimarket contact economies of scope and firm performance we integrate the efficiency and competitive effects of product market scope choice into a comprehensive model of economic performance and empirically test the model in the context of the u s airli

rivalry between strategic alliances abstract rivalry between strategic alliances is investigated in a model where each alliance member maximizes its own profit and some share of its partner s profit a complementary alliance confers a strategic advantage by allowing the partners to credibly commit to greater output owing to both within alliance complementarities and cross alliance substitutabilities although rivalry between different alliances can sometimes lead to a prisoners dilemma for firms it tends to improve economic welfare on the other hand an alliance that arises due purely to the threat of entry may reduce welfare

multimarket contact competition and pricing in banking abstract in this paper we assess the impact of multimarket contact of banks on their market power by means of a simultaneous equation model in which the divergence of price from marginal cost is a function of multimarket linkages the model is estimated using aggregate data from the italian regions for the years 1997 2009 our results show that multimarket contact is positively and significantly correlated to the market power index and is also connected to both home and non home market concentration the evidence is robust to changes in model specification and multimarket contact measures and supports the idea that firms which have a greater amount of contact are more likely to collude

duration for bonds with default risk abstract does approximating duration estimates by ignoring default risk lead to error in the two major duration applications measuring interest rate price elasticity and immunization we derive a general expression for duration in the presence of default risk based on jonkhart s term structure model on the term structure of interest rates and the risk of default journal of banking and finance 3 253 262 1979 extended to encompass risk aversion the model includes terms for default probabilities and default payoffs in each period as well as for a delay between the occurrence of default and the final default payoff our main conclusion is that practical duration applications involving bonds with default risk must employ duration measures adjusted for default risk

when can you immunize a bond portfolio abstract this paper presents a condition equivalent to the existence of a riskless shadow asset that guarantees a minimum return when the asset prices are convex functions of interest rates or other state variables we apply this lemma to immunize default free and option free coupon bonds and reach three main conclusions first we give a solution to an old puzzle why do simple duration matching portfolios work well in empirical studies of immunization even though they are derived in a model inconsistent with equilibrium and shifts on the term structure of interest rates are not parallel as assumed second we establish a clear distinction between the concepts of immunized and maxmin portfolios third we develop a framework that includes the main results of this literature as special cases next we present a new strategy of immunization that consists in matching duration and minimizing a new linear dispersion measure of immunization risk

living by the golden rule multimarket contact in the u s airline industry this paper examines empirically the effects of multimarket contact on pricing in the u s airline industry the analysis of the time series and cross sectional variability of airline fares in the 1000 largest domestic city pair routes reveals the presence of statistically significant and quantitatively important multimarket effects fares are higher in city pair markets served by carriers with extensive interroute contacts these findings are consistent with the claims of industry experts that airlines live by the golden rule i e that they refrain from initiating aggressive pricing actions in a given route for fear of what their competitors might do in other jointly contested routes during his testimony mr steven b elkins senior director of marketing systems development for northwest airlines cited an example in which northwest lowered fares on night flights that were flying with empty seats in a number of routes from minneapolis and upper midwest cities to various west coast cities he said that continental airlines swiftly responded by cutting prices in important northwest markets mr elkins s memo advises northwest pricing analysts we will live by the golden rule in his testimony he explained that the golden rule in that context was that i did not want my pricing analyst initiating actions in another carrier s market like chicago for fear of what that other carrier might do to retaliate wall street journal october 9 1990 p b1

inventories and sticky prices more on the microfoundations of macroeconomics the role of inventories in making prices sticky is studied by analyzing a dynamic linear quadratic model of a monopoly firm facing stochastic demand but able to store its finished goods in inventory it is shown that in contrast to the usual presumption firms that exhibit the smallest output responses to demand fluctuations may also exhibit the smallest price fluctuations specifically firms which have very flexible inventory storage facilities or are subjected to very transitory demand shocks will rely on inventories as buffers and will change neither production nor price very much on the other hand firms which have very inflexible storage facilities or whose demand shocks are quite permanent will display large swings in both price and output the standard assumption about inventory carrying costs that has been used in the literature that they are linear is shown to imply that production is impervious to fluctuations in demand it is also established that prices may respond more strongly to positive demand shocks than to negative ones if it is impossible to hold negative inventories i e to have unfilled orders the model offers an explanation for stickiness in relative prices however under certain circumstances it may help explain the persistence of inflation this abstract was borrowed from another version of this item

collusion at the extensive margin abstract we augment the multi market collusion model of bernheim and whinston 1990 by allowing for firm entry into and exit from individual markets we show that this gives rise to a new mechanism by which a cartel can sustain a collusive agreement collusion at the extensive margin whereby firms collude by avoiding entry into each other s markets or territories we characterise parameter values that sustain this type of collusion and identify the assumptions where this collusion is more likely to hold than its intensive margin counterpart specifically it is demonstrated that where duopoly competition is fierce collusion at the extensive margin is always sustainable finally we provide a theoretic foundation for the use of a proportional response enforcement mechanism

immunization as a maxmin strategy the purpose of this paper is to broaden the analysis of immunization when it is viewed as amaxmin strategy several results are demonstrated which provide a new interpretation of maxmin strategy by using a more general theory of lagrangians we clarify the exact assumptions required for the duration strategy and the maxmin strategy to be equivalent in a world with taxes it is shown that in a world with taxes the immunization strategy requires the portfolio to satisfy a constraint about the bond to be included in addition to the duration constraint