wage determination in brazil the growth of union bargaining power and informal employment this article examines wage determination in brazilian manufacturing during the 1980s and early 1990s it presents evidence to show that the reduction in state regulation of collective bargaining has led to the development of a system of wage determination which is increasingly characterised by rent sharing and insider trade union bargaining power real wages appear increasingly inflexible with respect to movements in open unemployment with a large informal sector disciplining formal sector wage bargaining and cushioning the impact of broader labour market conditions an important consequence of this is that the employment costs of a successful counter inflationary strategy may be very severe

spatial competition and vertical integration cement and concrete revisited reply in this review 1983 mark mcbride reconsiders the federal trade commission s ftc enforcement policy toward vertical mergers between cement and ready mix concrete firms in response to a significant increase in acquisitions of ready mix concrete firms by cement manufacturers during the 1960 s the ftc undertook a series of legal actions to block or dissolve the mergers the actions of the ftc constituted one of the most intensive efforts undertaken to date to challenge vertical mergers in a single industry mcbride p 1012 notes that the actions of the ftc provoked considerable debate concerning the motivation for the mergers both in the industry and in academe a significant number of articles were published advancing various reasons for the mergers in addition to the ftc s main contention that the mergers were motivated by a desire for captive markets it has been suggested that there were economies of integration or that the mergers were the outcome of an erroneous view of the potential benefits to foreclosure held by executives in the beleaguered cement industry 2 mcbride s 1983 paper offers another explanation for the mergers his argument is that vertical integration was undertaken to avoid rigid oligopolistic pricing in the cement industry 3 the empirical results presented by mcbride suggest that vertical integration was a significant factor in the decline of cement prices in the 1960 s the purpose of this comment is to point out some of the problems with mcbride s analysis in particular we show that the experimental design of his testing equation is faulty and does not offer a test of his hypothesis as a result mcbride s analysis does not provide convincing evidence on whether cement firms vertically integrated to avoid rigid oligopolistic pricing or if cement firms were merely reacting to prices that had already begun to decline our intent however is not to challenge mcbride s contention that vertical integration can provide lower prices to consumers rather we would argue that the evidence presented at the ftc hearings involving cement and ready mix concrete firms as well as mcbride s and others analyses illustrate the problems in discerning the motives for mergers 4

credible spatial preemption it is often argued that incumbent firms may deter entry by preemptive investment in new goods we show that these conclusions are reversed when multiproduct incumbentfirms may exit in response to entry once entrants are in an industry an incumbent will often want to withdraw some goods to prevent competition with the entrant from reducing profits on other goods such a reaction makes entry more attractive to a potential entrant the equilibrium industry structure is less likely to be monopolistic as the goods are better substitutes as exit costs are low and as the competition between producers of the same good is more intense

spatial competition among multi store firms abstract the paper analyzes spatial cournot competition among multi store firms it demonstrates that the complex problem of determining equilibrium store locations for competing multi store firms can be approximated by a simple one in which each firm behaves as a multi store monopolist in choosing its store locations a firm s equilibrium store locations often coincide with its monopoly locations and in general converge to its monopoly locations as the demand grows larger when the firms have an equal number of stores the stores belonging to competing firms agglomerate at discrete points that coincide with each firm s monopoly store locations

input demand elasticities for heterogeneous labor firm level estimates and an investigation into the effects of aggregation labor economists have paid increasing attention to the estimation of demand elasticities for heterogeneous labor the majority of these studies investigate the effect on wage rates resulting from exogenous changes in factor quantities i e the measurement of elasticities of complementarity examples of these studies abound borjas for example investigates the impact of differences in labor market representation on the earnings of racial groups 8 in another paper borjas defines immigrants as a separate labor group and is able to determine the impact of immigration on the wages earned by natives 9 berger defines labor inputs along education and gender lines thereby allowing for the investigation of changes in the age education composition of the work force on wage rates 5 and grant and hamermesh study the effect of increasing female labor force participation on the wages earned by youth and adults 17 less attention has been paid to the study of the responsiveness of employment to exogenous changes in wage rates i e the measurement of elasticities of substitution less attention has been focused on this issue because the data requirements are more stringent since in order to presume that wage rates are exogenously determined the unit of observation must be small ideally establishmentor firm level data would be used the relative inaccessibility of these type of data has led researchers to use more aggregated figures such as smsa level or industry level data to address microissues as long as wage rates are determined exogenously the unit of observation chosen is appropriate there are real concerns however about the adequacy of more aggregated units to describe the behavior of firms 2 this study addresses the issue of whether micro level data are in fact needed to accurately measure elasticities of substitution among labor groups a firm level data set that includes input

time to build monetary shocks and aggregate fluctuations abstract the idea that the investment process takes time to produce finished capital goods was an integral part of kydland and prescott s early work on real business cycles but this feature has been dropped in much recent work mainly because it seemed to have little effect on macroeconomic dynamics with a generalization of the time to build feature that incorporates multiple types of capital however a new keynesian model can produce u shaped responses in output investment and inflation to a monetary policy shock such responses are not found in many studies that assume no time to build friction in addition different specifications of the time to build structure result in substantially different response patterns for these aggregate variables

price dynamics and production lags this paper provides a new explanation of why inflation is sluggish in response to aggregate demand shocks and why aggregate output changes as result of such shocks we argue that these phenomena are related to lags between inputs and outputs in the production process production lags for short the broad intuition is that production activities in a modern economy are interconnected through complex input output relations with production lags within individual firms and that it takes considerable time for cost and price changes to penetrate the entire input output system our analysis provides a rationale for a prolonged inverse relation between inflation and unemployment the paper suggests that the interaction of inflation persistence and unemployment persistence may offer a possible explanation of high and prolonged european unemployment this abstract was borrowed from another version of this item

multiple product firms a nested logit approach this paper proves the existence of a symmetric equilibrium with multiproduct firms using a nested logit model of demand the demand model is parameterized by two variables that characterize different dimensions of preference for variety these reflect intragroup heterogeneity and intergroup heterogeneity a group or nest being the set of products produced by a firm there are then two dimensions to market performance the total number of firms and the range of products produced per firm it is shown that the market equilibrium involves an excessive number of firms but each firm provides too few products copyright 1992 by blackwell publishing ltd

the principle of minimum differentiation holds under sufficient heterogeneity the so called principle of minimum differentiation stated by hotelling has been challenged by many authors this paper restores the principle by showing that n firms locate at the center of the market and charge prices higher than the marginal cost of production when heterogeneity in consumers tastes is large enough

quantity competition in a spatial model the authors analyze a duopoly model where firms first choose locations on a line segment and then choose quantities in the second stage pure strategy quantity equilibria fail to exist for locations close together for low transport costs near agglomeration occurs and the firms choose locations where pure strategy quantity equilibria exist as transport costs rise firms become less direct competitors as they move away from the center of the market coauthors are james f klein eytan sheshinski and steven m slutsky we analyse a duopoly model where firms first choose locations on a line segment and then choose quantities in the second stage pure strategy quantity equilibria fail to exist for locations close together for low transport costs near agglomeration occurs and the firms choose locations where pure strategy quantity equilibria exist as transport costs rise firms become less direct competitors as they move away from the centre of the market coauthors are james f klein eytan sheshinski and stephen m slutsky

wage bargaining and the phillips curve the identification and specification of aggregate wage equations most economists believe that wage setting is very important for understanding macroeconomic behavior but the form of wage equations commonly estimated suffer from problems of identification the aim of this paper is to consider whether these problems are inevitable and if they are not to suggest ways in whi ch one can estimate structural models of wage setting it is argued that if one confines attention to models of wage bargaining t hat are commonly used identification of the parameters of wage setting should not be a problem and that the most appropriate form of an aggregate wage equation should be a phillips curve copyright 1993 by royal economic society

deregulation of shopping hours the impact on independent retailers and chain stores this paper studies shopping hour decisions by retail chains and independent competitors we use a salop type model where retailers compete in prices and shopping hours our results depend significantly on efficiency differences between retail chain and independent retailer if the efficiency difference is small the independent retailer may choose longer shopping hours than the retail chain and may gain from deregulation at the expense of the retail chain the opposite result emerges when the efficiency difference is large then the retail chain may benefit whereas the independent retailer loses from deregulation

imperfect competition in the international energy market a computerized nash cournot model this paper describes the conceptual structure properties and solution approach of a computerized model of the international energy market the model treats energy producers as players in a multistage noncooperative game the goal of each player or cartel of players is assumed to be maximization of discounted profit subject to technical political and resource constraints the model calculates that collection of intertemporal extraction and price paths from which a player can unilaterally deviate only at a loss the open loop nash equilibrium the model integrates the theory of exhaustible resources due to hotelling and the theory of oligopoly due to nash and cournot although useful as a teaching device to illustrate theoretical results its main function is to facilitate analysis of real world resource problems the model is flexible allowing the user to specify not only cost demand and reserve information but also assumptions about who belongs to what coalition two shortcomings deserve note t

endogenous growth and time to build the ak case abstract in this paper a continuous time ak model is fully analyzed under the time to build assumption the existence and uniqueness of a real balanced growth path as well as oscillatory convergence are proved transversality conditions and capital depreciation are highlighted moreover it has been shown how the introduction of the time to build assumption supports some interesting empirical evidences such as the negative link between mean output growth and output growth volatility finally numerical simulations are provided for different choices of the time to build delay in order to clarify the analytical results

sticky price models of the business cycle can the contract multiplier solve the persistence problem we construct a quantitative equilibrium model with firms setting prices in a staggered fashion and use it to ask whether monetary shocks can generate business cycle fluctuations these fluctuations include persistent movements in output along with the other defining features of business cycles like volatile investment and smooth consumption we assume that prices are exogenously sticky for a short time persistent output fluctuations require endogenous price stickiness in the sense that firms choose not to change prices much when they can do so we find that for a wide range of parameter values the amount of endogenous stickiness is small thus we find that in a standard quantitative model staggered price setting alone does not generate business cycle fluctuations

an introduction to the wage curve en conomists and policymakers are interested in understanding the forces that determine the level of unemployment and the level of wages this paper describes an empirical discovery made with the help of international microeconometric evidence covering more than a dozen nations about a link between these two variables the connection can be portrayed on a graph with the level of unemployment on the horizontal axis and the level of wages on the vertical axis then the wage curve as shown in figure 1 is a downwardsloping locus this relationship tells us that holding others things constant if a region has a rise in unemployment in a particular year those who live there will have a fall in their wages in that year what does this curve mean how in a field where fully controlled experiments are almost impossible could there be any convincing scientific basis for this wage curve what is the relationship between the wage curve and a phillips curve other than that the curve of figure 1 looks like a phillips curve with the vertical axis mislabeled how does the wage curve fit into existing economic knowledge and is the empirical finding consistent with competitive theory this paper sketches answers to these kinds of questions the discussion draws on our book the wage curve blanchflower and oswald 1994 where the points raised here are investigated more fully it also rests upon work done by other economists whose work is listed in the paper and the bibliography

prices productivity and wage bargaining in open economies according to the standard union bargaining model unemployment benefits should have big effects on wages but product market prices and productivity should play no role in the wage bargain we formulate an alternative strategic bargaining model where labour and product market conditions together determine wages a wage equation is derived and estimated on aggregate data for four nordic countries wages are found to depend not only on unemployment and the replacement ratio but also on productivity international prices and exchange rates there is evidence of considerable nominal wage rigidity exchange rate changes have large and persistent effects on competitiveness

habit formation in consumption and its implications for monetary policy models this paper explores a monetary policy model with habit formation for consumers in which consumers utility depends in part on current consumption relative to past consumption the empirical tests developed in the paper show that one can reject the hypothesis of no habit formation with tremendous condence largely because the habit formation model captures the gradual hump shaped response of real spending to various shocks the paper then embeds the habit consumption specication in a monetary policy model and nds that the responses of both spending and inflation to monetary policy actions are signicantly improved by this modication jel d12 e52 e43

time to build and aggregate fluctuations abstract this paper studies the contribution of time to build to the explanation of business cycle phenomena using a simple version of the neoclassical model the analysis shows that it is not evident that multiperiod construction is crucial to the theory of fluctuations

spatial competition and spatial price discrimination the analysis of spatial competition under conditions of free entry which derives its major impetus from the seminal work of losch 1954 has been conducted in general on the assumption that the competitive firm will adopt an f o b pricing scheme see for example capozza and van order 1978 and holahan 1978 greenhut 1956 does consider some of the implications of discriminatory pricing within competitive markets but his analysis adopts an essentially short run view and provides little rationale for the choice of such a pricing policy by competitive firms this is in contrast with developments in the analysis of spatial monopoly the early work of singer 1937 and hoover 1937 and subsequent developments by for example greenhut 1956 beckmann 1976 beckmann and ingene 1976 greenhut and greenhut 1977 holahan 1975 and norman 1977 indicate that the spatial monopolist should adopt a discriminatory spatial pricing policy where spatial price discrimination is taken conventionally to mean that delivered prices do not follow an f o b scheme but that all concumers equidistant from a particular supplier pay the same price it is rarely however that the results generated by the analysis of spatial monopoly are reconsidered in the analysis of spatial competition in particular although we know that spatial price discrimination will in general increase a monopolist s profit the assumption that profit maximising spatially competitive firms will adopt f o b pricing schemes has rarely been questioned and has not been questioned within the loschian competitive framework greenhut and ohta 1975a chapter 8 and chapter 8 appendix i are notable exceptions but in both cases they depart from the loschian scheme the first objective of this paper is therefore to show that when loschian competitive firms are allowed the option of discriminatory pricing i e are free of institutional constraints which require f o b pricing they will be forced to exercise that option in order to maintain normal profits secondly we shall show that if competitive conditions change the form of price discrimination will also change and that under certain competitive conditions the degree of discrimination will increase with the degree of competition leading eventually to uniform pricing thirdly we compare two competitive cases with multi plant monopoly and derive the spatial analogue of the conventional spaceless monopoly perfect competition comparison the monopolist s plants will be larger in area and total output than each competitive firm but will supply less per consumer at a higher average price welfare comparisons are less clear cut in that they are dependent upon the type of competition we assume we show however that welfare maximisation requires marginal cost pricing where marginal cost includes transport costs and so requires f o b pricing if there are economies of scale to production it follows that welfare maximisation will require production subsidy

investment adjustment costs an empirical assessment we evaluate empirical evidence for costs that penalize changes in investment using us industry data in aggregate models such investment adjustment costs have been introduced to help account for a variety of business cycle and asset market phenomena so far no attempt has been made to estimate these costs directly at a disaggregated level we consider an industry model with investment adjustment costs and estimate its parameters using generalized methods of moments the ndings indicate small costs associated with changing the ow of investment at the industry level the weighted average of the industry elasticities with respect to the shadow price of capital which depends inversely on the adjustment cost parameter is more than seven times larger than the largest estimate based on aggregate data we examine potential sources which may account for the large industry aggregate dierence overall our results suggest

testing steady state implications for the nairu estimates of the nairu are usually derived either from a phillips curve or from a wage curve this paper investigates the correspondence between the operational nairu concepts and the steady state of a dynamic wage price model we derive the parameter restrictions that secure that correspondence the full set of restrictions can be tested by econometric analysis of the wage price system and this method is demonstrated for norwegian data a set of necessary conditions can be tested from estimated wage curves alone existing international evidence from empirical wage equations are reinterpreted in light of these conditions

on distance metrics in location problems product space metrics reflect the complementarity of product attributes and lead to different geometries in multidimensional spaces this matters for optimal product positioning i consider how a planner should design two substitute public goods with multiple attributes to best serve different needs attribute complementarity affects whether a given menu dominates another using an extension of the pareto criterion distancing the goods proportionately in every attribute guarantees improvement when tastes are maximally diverse the intuition is that the planner must minimize overlap in the populations the goods serve since benefits are wasted in appealing to the same individual with two offerings jel c65 d78 h41

sequential entry and deterrence with competitive spatial price discrimination abstract this paper analyzes sequential entry with perfect foresight in a competitive spatial price discrimination model with both an exogenous and an endogenous number of firms the spne locations do not coincide with the social cost minimizing locations

time to build capital revisiting investment cash flow sensitivities a large body of empirical work has established the significance of cash flow in explaining investment dynamics this finding is further taken as evidence of capital market imperfections we show using a perfect capital markets model that time to build for capital projects creates an investment cash flow sensitivity as found in empirical studies that may not be indicative of capital market frictions the result is due to mis specification present in empirical investment q equations under time to build investment in addition time aggregation error can give rise to cash flow effects independently of the time to build effect importantly both errors arise independently of potential measurement error in q evidence from a large panel of u k manufacturing firms confirms the validity of the time to build investment channel

cournot competition yields spatial agglomeration most theoretical models of spatial competition show a strong tendency toward spatial dispersion of firms yet common observations suggest that firms tend to agglomerate in this paper the authors show that competition between cournot type oligopolists that discriminate over space leads to spatial agglomeration one implication is that firms do not necessarily earn supernormal profits at the free entry equilibrium copyright 1991 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

when to exit a product evidence from the u s motion picture exhibition market when is it optimal for a multi product firm to exit a product we analyze strategic product exit using data on motion pictures exhibition choices in a major metropolitan first run market to estimate the survivor function for films at a given theatre this analysis indicates that a film s survival at a particular theatre is affected by intra firm relative performance and interfirm competitive pressures we find that theatres within chains avoid business stealing preliminary analysis further suggests that theatres compete for market share with neighboring theatres by increasing the time to exit when the competing theatre is owned by a different chain this abstract was borrowed from another version of this item

the impact of affirmative action on labor demand a test of some implications of the le chatelier principle this paper presents an alternative approach to measuring the impact of affirmative action on firms affirmative action is modeled as a series of hiring quotas if the quotas are binding then a firm subject to affirmative action will operate with greater costs of production have less elastic demand for inputs and be less able to substitute between most inputs the results are consistent with the hypothesis that affirmative action regulations significantly constrain firms behavior own wage elasticities are less elastic and most inputs are less substitutable for constrained firms further affirmative action raises costs by 6 5 percent for firms subject to the program copyright 1992 by mit press

labour market policy and unemployment the paper discusses three aspects of the system for unemployment support first active labour market programmes as a means of re allocating labour from high unemployment to low unemployment sectors are analysed and it is concluded that wage raising accommodation effects may be a serious problem second the possibility of strengthening incentives for wage moderation by differentiating employee and or employer contributions to unemployment insurance are discussed third the question is raised whether there may exist other institutional set ups for providing unemployment support that are more efficient in terms of returning the unemployed to work than government run systems

spatial price discrimination with heterogeneous products product heterogeneity is introduced into the context of spatial price discrimination many of the strong properties of the standard homogeneous goods case which are attained as a limit case here are shown to be no longer valid in particular the social optimum is no longer sustainable as a market equilibrium unless products are either identical or else very different

spatial cournot competition among multi plant firms in a circular city we characterize equilibrium plant locations for a spatial multi plant cournot oligopoly in a circular city previous work demonstrates that for a two plant duopoly all four plants are equally spaced we establish that the equilibrium location pattern is unique if there are two firms with an equal number of plants in most other scenarios multiple equilibria arise next we endogenously determine both the number of plants per firm and plant locations for a duopoly it is shown that the subgame perfect nash equilibrium may not be unique and for identical set up costs the firms may choose different numbers of plants

consumer benefiting exclusive territories i investigate the effect of exclusive territories which are typical vertical controls imposed by upstream firms using shipping spatial models i consider an industry that consists of many independent local markets an upstream monopolist restricts competition between downstream firms using exclusive territories i find that exclusive territories reduce the prices of final products in all local markets in quantity setting competition in price setting competition they raise prices in half the local markets reduce them in other markets and also reduce the total consumer surplus jel classification l42 r32 a propos de territoires exclusifs qui profitent aux consommateurs l auteur analyse les effets de la regle des territoires exclusifs qui est souvent imposee comme controle vertical par les entreprises en amont a l aide de modeles spatiaux de livraison on considere le cas d une industrie composee de plusieurs marches locaux independants un monopoleur en amont reduit la concurrence entre entreprises en aval en imposant la regle des territoires exclusifs on decouvre que cette regle reduit les prix du produit final dans tous les marches locaux s il y a concurrence par les quantites s il y a concurrence par les prix la regle accroit les prix dans la moitie des marches locaux les reduit dans les autres et reduit aussi le surplus au consommateur

where to locate in a circular city abstract we study the location choices by cournot oligopolists in a circular market where consumers are located uniformly along the circumference we analyze the subgame perfect nash equilibria spne of a two stage location quantity game we demonstrate that the equidistant location pattern is only one of the many equilibrium location patterns that arise in a circular market nonequidistant multiple or a continuum of location equilibria may also arise both spatial agglomeration and dispersion or a combination of agglomeration and dispersion may occur in equilibrium in the case of infinitely many location equilibria we establish the welfare equivalence of the equilibrium location patterns

partial agglomeration or dispersion in spatial cournot competition 1 introductionsince the seminal work of hotelling 1929 a rich and diverse literature on spatial competition has emerged location models can be classified into two types one type is shipping or spatial price discrimination model where sellers bear transport costs the other is shopping or mill pricing model where buyers pay for transport for each type one can have either bertrand type price setting or cournot type quantity setting 1most studies on location theory use shopping mill pricing models with bertrand competition although cournot and bertrand types of non spatial models are equally popular the body of literature on spatial competition that uses cournot type models is relatively small economists have recently considered shipping models with cournot competition hamilton thisse and weskamp 1989 and anderson and neven 1991 carry out pioneering works on location models 2 they use linear city models and show that all firms agglomerate at the central point pal 1998 shows that their result is crucially dependent on the assumption of a linear city he investigates a circular city duopoly model3 and finds that an equidistant location pattern appears in equilibrium that is locational dispersion appears 4 matsushima 2001a extends pal s model to an n firm oligopoly and shows another equilibrium where half of the firms locate at one point and the other half locate at the opposite point partial agglomeration these results indicate the multiplicity of equilibria in spatial cournot models with a circular city the multiplicity of equilibria restricts the applicability of the model because the model does not give us a distinct prediction in this article we take a close look at pal 1998 and matsushima 2001a we try to solve this problem by extending their linear transport cost model to one with nonlinear transport cost 5 we consider a simplified model the numbers of firms and markets and so possible locations are four four firms choose location a b c or d see if each of the four firms chooses a different location we call this outcome pal type if two firms locate at a and the other two locate at c we call this outcome matsushima type we find that the pal type equilibrium is much more robust because i pal type equilibrium always exists as long as transport cost is increasing in distance while matsushima type equilibrium fails to exist when the transport cost function is significantly convex or concave proposition 1 ii if firms choose their locations sequentially the unique equilibrium outcome is pal type under nonlinear transport cost functions proposition 2 and iii the profit of each firm in pal type is never smaller than that in matsushima type and the former is strictly larger if the transport cost function is nonlinear proposition 3 we also compare the welfare implications of pal type and matsushima type models if the transport cost function is linear the two outcomes yield exactly the same profits consumer surplus and total social surplus however this equivalence does not hold if the transport cost function is nonlinear either convex or concave in this case pal type yields greater total social surplus and profit of each firm while matsushima type yields greater consumer surplus these results indicate that the welfare implications are sensitive to whether or not the transport cost function is linear anderson and neven 1991 show that in the linear city model a strong concavity in transport cost changes the equilibrium outcome this result is related to our results but we emphasize that our results are different from theirs first we show that both concavity and convexity of the transport cost function affect the results while in anderson and neven 1991 only strong convexity changes the result second in our propositions 2 and 3 even a slight nonlinearity changes the results

can price competition dominate market segmentation this note analyses duopoly competition in a two stage location price game while allowing each firm to establish a couple of outlets both the circle and the line model of spatial competition are considered our main result is clear cut in equilibrium neither firm will take up the opportunity of opening two stores this is a warning that market segmentation i e competition from multiple outlets might not be attractive at all because it entails more intense price competition

competition of firms discriminatory pricing and location1 two costlessly mobile firms are to be located in a market region a subset of the plane the firms compete by setting locations and delivered price schedules to study this competitive stiuation an appropriate extensive form game is defined along with an appropri ate noncooperative solution concept existence and general properties of the equilibrium are demonstrated among the results are each firm increases its profit by locating so as to decrease total cost to both firms of serving the market firms will never locate coinciden tally if they have identical production costs and transport cost rates or if these are different and the firms are located in a circular market region having a uniform demand distribution this paper studies competition between two profit maximizing firms in space who are costlessly mobile and may discriminate in price we will allow the firms to set locations and delivered price schedules and we will be concerned with the existence and properties of equilibria in location and price starting with hotelling 9 the spatial competition literature has focused on location on bounded linear markets by two or more firms hotelling assumed identical firms that produced a single good with constant cost of production and considered consumers to be uniformly distributed and to have inelastic demand he also assumed that the consumers pay transport cost and purchase the good from the cheapest source hotelling claimed that a nash equilibrium in locations for the two firm market existed and yielded back to back locations at the center of the market many authors most recently d aspremont gabszewicz and thisse 2 have noted that an equilbrium in prices and location does not exist for hotelling s model however if the firms employ identical exogeneously specified prices hotelling s conclusions hold subsequent work by smithies 14 hartwick and hartwick 7 and eaton 3 claimed to show that a nash equi librium in f o b prices and locations can exist in markets with a uniform distribu tion of consumers each of whom have identical elastic demand functions for the two and three firm problems the work of d aspremont et al casts doubt on these conclusions without the adoption of restrictive conditions our work contrasts with these works and related research which has dealt with linear markets with uniform distributions of customers and with identical firms our work will involve markets that are subsets of the plane having nonuniform distributions of customers our firms will be allowed to be different that is have differences in production and transport costs however the fundamental difference in our approach is that our firms will set discriminatory prices and not price f o b in many ways our work will represent the discriminatory pricing

mixed oligopoly and spatial agglomeration abstract we investigate a mixed market where a state owned welfare maximizing public firm competes against profit maximizing private firms we use a circular city model with quantity setting competition in contrast to a pure market case discussed by pal 1998a spatial agglomeration of private firms always appears in equilibrium all private firms locate at the same point and the public firm locates at the opposite side we also find that this equilibrium pattern of the location is second best provided that output of each private firm cannot be controlled by the social planner jel classification h42 l13 oligopole mixte et agglomeration spatiale les auteurs examinent un marche mixte ou une entreprise publique possedee par l etat et cherchant a maximiser le niveau de bien etre est en concurrence avec des entreprises privees qui cherchent a maximiser leurs profits on utilise un modele de cite circulaire ou la concurrence se fait en choisissant la quantite produite en contraste avec le cas du marche parfait discute par pal 1998a l agglomeration spatiale des entreprises privees parait etre en equilibre toutes les entreprises privees se localisent au meme point et l entreprise publique se localise du cote oppose il appert que ce pattern d equilibre de localisation est un equilibre de second ordre compte tenu du fait que la production de chaque entreprise privee ne peut etre controlee par le planificateur social