technological regimes schumpeterian patterns of innovation and firm level productivity growth the paper investigates the relationships between technological regimes and firm level productivity performance and it explores how such a relationship differs in different schumpeterian patterns of innovation the analysis makes use of a rich dataset containing data on innovation and other economic characteristics of a large representative sample of norwegian firms in manufacturing and service industries for the period 1998 2004 first we decompose tfp growth into technical progress and efficiency changes by means of data envelopment analysis we then estimate an empirical model that relates these two productivity components to the characteristics of technological regimes and a set of other firm specific factors the results indicate that 1 tfp growth has mainly been achieved through technical progress while technical efficiency has on average decreased 2 the characteristics of technological regimes are important determinants of firm level productivity growth but their impacts on technical progress are different from the effects on efficiency change 3 the estimated model works differently in the two schumpeterian regimes technical progress has been more dynamic in schumpeter mark ii industries while efficiency change has been more important in schumpeter mark i markets

consumer support for environmental policies an application to purchases of green cars this paper focuses on how consumer motivation can be tapped in order to encourage the adoption of cleaner technologies consumers are heterogeneous they may be guided by intrinsic motivation or extrinsic motivation while information provision policies such as the energy label for cars may be effective in encouraging certain consumers to adopt green cars financial incentive schemes such as subsidies or fines may be more persuasive for extrinsically motivated consumers we develop a dynamic theory of adoption of environmental innovations in which information provision policies are followed by financial incentives first carrot then stick incentives analysis of a survey dataset of swiss households observes considerable heterogeneity in terms of support of information provision or financial incentive policies in line with our conjectures our results will be of particular interest to policymakers interested in guiding consumers towards cleaner technologies

on the equivalence of resale price maintenance and quantity restrictions abstract when demand is known with certainty there is a clear mapping between a monopolist s pricing and output decisions this suggests an equivalence between a monopolist manufacturer specifying a minimum maximum retail price and imposing a maximum minimum quantity on its retailers this paper shows that while the effect of maximum rpm can always be replicated by an appropriate quantity floor the minimum rpm outcome cannot always be replicated by an appropriately chosen quantity ceiling as such the analysis provides one reason that manufacturers will choose a price floor rather than quantity ceiling even though a quantity ceiling would appear to lead to lower monitoring costs

does the per se rule deter vertical price fixing i introduction beginning with the wide scale introduction of branded goods in the late nineteenth century manufacturers have often tried to dictate minimum resale prices to the retail outlets carrying their products and since roughly the same time antitrust experts have debated why they would do so 1 less attention has focused on what manufacturers do when they can not impose minimum prices even though legal obstacles have forced them to look for alternatives so what do manufacturers do when they cannot legally set the prices their outlets charge 2 many antitrust officials believe they go right on setting prices either flaunting the law or finding some means to circumvent it barrett 1991 quotes former new york state antitrust chief lloyd constantine as saying that the practice is ubiquitous but based upon winks and nods rather than written agreements that could be used in court new york attorney general robert abrams 1991 argues that vertical price fixing is endemic claiming that antitrust officers can recount scores of tales of retailers calling our offices too scared to give their names telling of coercion and intimidation by manufacturers representatives and rival dealers because their prices were too low former ftc commissioner terry calvani argues that a manufacturer practicing resale price maintenance would have to have an i q two points lower than a carrot to get caught 3 the prospects for wink and nod resale price maintenance are not hard to appreciate for example suppose a manufacturer wants to impose a 500 sanction on any discount outlet if it cannot do so overtly it may instead impose a lump sum charge of 500 on all outlets and ex post reward non discount outlets with a 500 rebate given this scheme s transparency courts legislators and antitrust officials should not be fooled yet the rebates could be indirect and discreet they could be spread over several periods and parceled out in small quantities as compensation for point of sale services to defray overhead to pay for advertising or training and so forth hence it may be hard for outsiders to prove a link between what the manufacturer pays each retailer and that retailer s price moreover in some instances antitrust officials may want an excuse to loosen the legal restrictions on resale price maintenance and may themselves wink and nod at these practices finally antitrust officials cannot always and perhaps not often distinguish legitimate cost sharing arrangements from maneuvers to influence resale prices as such they must proceed carefully manufacturers can employ two other legal means to fix resale prices first manufacturers can coordinate retailers meet the competition guarantees antitrust experts have long believed that on occasion retailers can independently offer meet the competition guarantees to their customers to discourage price competition 4 here a manufacturer coordinates retailers efforts by financing some or all of the meet the competition related rebates they make so in equilibrium all retailers adopt the suggested price while previous models of meet the competition guarantees focus on tacit horizontal price fixing this paper examines explicit vertical price fixing second the manufacturer can persuade retailers to charge its suggested price by guaranteeing the margins of those victimized by price cutting rivals in equilibrium no outlet wants to cut price first so discounting does not occur at all manufacturers have various other means to influence their dealers resale prices in addition to such well known instruments as consignment sales and exclusive territories manufacturers can agree to buy back dealers unsold inventories or parcel out merchandise only as demand for it materializes they can also use devices such as markdown allowances to influence when and by how much dealers discount if demand turns out low presumably this list does not exhaust the possibilities for innovative manufacturers seeking to subsidize dealers that cooperate and to discriminate against those that do not

facilitating practices the effects of advance notice and best price policies even if firms in a market choose discount prices noncooperatively the use of most favored customer and meet or release contracts enables those firms to adopt quantity choice strategies consequently there can be a range of list prices that are impervious to unilateral nonselective discounts but this range does not include prices above the level determined in a cournot equilibrium the practice of advance public notification of list price increases can facilitate the establishment of such supracompetitive list prices as was argued in the recent ftc ethyl case the possibility of offering discounts selectively results in a much more competitive situation

the competitive implications of top of the market and related contract pricing clauses this article examines the competitive implications of contract pricing arrangements which link the contract price to the subsequent cash price we focus on so called top of the market pricing tomp in cattle procurement the tomp clause is shown to have anticompetitive consequences when the same buyers who purchase contract cattle with the tomp clause also compete to procure cattle in the subsequent spot market the tomp clause reduces packers incentives to compete aggressively in the spot market although tomp pricing is not in producers collective interest rational sellers may nonetheless sign these contracts with little or no financial inducement

guaranteed lowest prices do they facilitate collusion abstract the effects of a policy guaranteeing lowest price are analyzed in a two stage game where firms first decide whether to adopt such a policy and then choose prices symmetric and asymmetric games are solved to examine the extent to which prices can rise to collusive levels

alternative models of individual behaviour and implications for environmental policy abstract most insights of environmental economics are in line with the standard neoclassical economic model of rational behaviour formulated in terms of maximization of utility in general or of profits in particular the standard theory of environmental policy is a case in point however the maximization hypothesis and its methodological foundation have been criticized on many grounds related to a lack of either logical or empirical content moreover over the years a great many alternative models of behaviour have been proposed both criticism and alternatives are surveyed here attention is devoted to relevant insights from the philosophy of science the notion of methodological individualism and other criticism the alternative behavioural models include bounded rationality and satisficing lexicographic preferences habitual behaviour incommensurability and multicriteria evaluation and various models of behaviour under uncertainty major implications of the criticism and alternative models of individual behaviour for environmental policy theory are outlined

the effects of market practices in oligopolistic markets an experimental examination of the ethyl case this study reports on the performance of experimental markets characterized by industrial structure and practices similar to those at issue in the ethyl case the central question is whether price competition is affected by the practices of advanced notification of price changes and most favored nation contracts or is determined by industrial organization and concentration alone

on the competitive effects of price matching policies abstract this paper challenges the conventional wisdom that price matching policies lead to supracompetitive prices by reducing firms incentives to undercut rivals i argue that price matching and price beating policies are more appropriately viewed as a means of price discrimination and develop a model that demonstrates their use as such analysis of this model shows that in contrast to the results of the existing literature price matching and price beating may raise or lower equilibrium prices relative to the equilibrium in which firms may not adopt such policies

did the airline tariff publishing case reduce collusion abstractin december 1992 the u s department of justice filed suit against eight major domestic airlines and the airline tariff publishing atp company in order to reduce opportunities for collusion in the industry the lawsuit ended with consent decrees limiting the ability of airlines to communicate surreptitiously through the shared fare database this paper measures the effects of the litigation and its settlement on industry performance comparing changes in outcomes between market segments that were more and less likely to be affected by the atp case prices fell in response to the investigation but increased following the settlement while the number of tickets sold in affected markets declined the importance of multimarket contact also declined and then recovered the atp case had at best a temporary effect on airline collusion

car buyers and fuel economy abstract this research is designed to help researchers and policy makers ground their work in the reality of how us consumers are thinking and behaving with respect to automotive fuel economy our data are from semi structured interviews with 57 households across nine lifestyle sectors we found no household that analyzed their fuel costs in a systematic way in their automobile or gasoline purchases almost none of these households track gasoline costs over time or consider them explicitly in household budgets these households may know the cost of their last tank of gasoline and the unit price of gasoline on that day but this accurate information is rapidly forgotten and replaced by typical information one effect of this lack of knowledge and information is that when consumers buy a vehicle they do not have the basic building blocks of knowledge assumed by the model of economically rational decision making and they make large errors estimating gasoline costs and savings over time moreover we find that consumer value for fuel economy is not only about private cost savings fuel economy can be a symbolic value as well for example among drivers who view resource conservation or thrift as important values to communicate consumers also assign non monetary meaning to fuel prices for example seeing rising prices as evidence of conspiracy this research suggests that consumer responses to fuel economy technology and changes in fuel prices are more complex than economic assumptions suggest the us department of energy and the energy foundation supported this research the authors are solely responsible for the content and conclusions presented

technology and the dynamics of industrial structures an empirical mapping of dutch manufacturing this paper explores the empirical link between on the one hand innovation and on the other hand industrial structure and dynamics in the netherlands we use the concept of technological regimes as the guiding framework to interpret this relationship the data are drawn from the production statistics and the business register of manufacturing firms in the netherlands and the second community innovation survey a classification of technological regimes that refines pavitt s taxonomy is applied to the data our analysis is aimed at identifying the variables that are best able to discriminate between technological regimes for our dutch case we find that a mix of innovation related and market structure related variables account for most variability and broad differences across regimes dynamic market structure variables account for an additional share of variability and finer differences across regimes overall we conclude that the concept of technological regimes provides a useful framework that helps to shed further light on the relationship between innovation and market structure

technological regimes and firm survival evidence across sectors and over time in addition to the usual variables representing firm and industry specific features that impact the firm s survival this paper uses three r d related variables to reflect two schumpeterian technological regimes creative destruction the entrepreneurial regime and creative accumulation the routinized regime after controlling for age size entry barriers capital intensity the profit margin the concentration ratio the profit cost ratio and entry rates the empirical results confirm the theoretical relationship between technological regimes and the survival rate of new firms new firms are more likely to survive under the entrepreneurial regime moreover this effect is larger within the younger cohorts of firms than within the older ones

constructive consumer choice processes consumer decision making has been a focal interest in consumer research and consideration of current marketplace trends e g technological change an information explosion indicates that this topic will continue to be critically important we argue that consumer choice is inherently constructive due to limited processing capacity consumers often do not have well defined existing preferences but construct them using a variety of strategies contingent on task demands after describing constructive choice consumer decision tasks and decision strategies we provide an integrative framework for understanding constructive choice review evidence for constructive consumer choice in light of that framework and identify knowledge gaps that suggest opportunities for additional research

dynamic duopoly with best price clauses this article investigates best price clauses as a strategic devise to facilitate collusion in a dynamic duopoly game best price clauses guarantee rebates on the purchase price if a customer finds a better price after his purchase two different price clauses are distinguished most favored customer and meet or release i examine the collusive potential of both clauses in a finite horizon duopoly model with homogeneous durable goods in each period new consumers enter the market i show that in this context meet or release clauses have a greater anticompetitive potential than most favored customer clauses

how low is a guaranteed lowest price a game based on the bertrand duopoly model is constructed to study the effects of price guarantee policies before it chooses a list price a firm can make a binding commitment to match or beat its competitor s price the effectiveness of these price guarantee policies in facilitating price collusion depends on the solution concept used furthermore there exists an equilibrium in which neither firm offers any price guarantees and each firm sets price equal to marginal cost

learning and noisy equilibrium behavior in an experimental study of imperfect price competition we consider a duopoly pricing game with a unique bertrand nash equilibrium the high price firm has a nonvanishing market share however and intuition suggests that observed prices may be positively related to this market share this relationship is implied by a model in which players make noisy logit best responses to expected payoff differences the resulting logit equilibrium model was used to design an experiment in which the high price firm s market share varies the model accurately predicts the final period price averages a naive learning model predicts the observed differences in the time paths of average prices

technical note a comparison of bertrand and cournot profits in oligopolies with differentiated products we compare equilibrium profits of bertrand price and cournot quantity competition in oligopolies with an arbitrary number of nonsymmetric firms offering differentiated substitutable products under an affine demand function we provide a precise characterization of the profit relationship in terms of 1 the number of firms 2 their relative quality and cost differences and 3 the competition intensity defined as the maxiumum absolute value of total change in competitors demand over change in own demand due to a unit change in own price we first examine the case where firms have the same demand sensitivity to own price and the same demand sensitivity to competitor prices but different cost and quality parameters for this case we prove that the total profit of the industry under cournot competition is at least as high as the total profit under bertrand competition if the number of firms is less than 28 or if the competition intensity is less than 0 909 or if the differences in quality and cost competitiveness between firms are small we also prove that for each firm the profit achieved under cournot competition is at least as high as the profit achieved under bertrand competition if the number of firms is less than eight or if the competition intensity is less than 0 739 we then provide numerical and analytical results that qualitatively support the same conclusions for general affine demand functions with variable demand sensitivities to prices

linear inequality methods to enforce partnerships under uncertainty an overview we review different generic conditions on stochastic outcome functions to enforce either efficient or nearly efficient partnerships their logical relationship is explored two kinds of conditions are considered however the property for an action profile to be compatible plays a crucial role in both kinds also two kinds of enforcement mechanisms are considered enforcement through utility transfers and enforcement through repetition

cartel price announcements the vitamins industry abstract the primary manufacturers of vitamins admitted to participating in international market share agreement cartels for several years during the 1990s their announced price increases appeared in leading trade journals we show that price announcements during the cartel period and the lead times before these prices took effect were fundamentally different in character from price announcements when explicit collusion was less likely these differences are consistent with our model of price announcements where we account for the importance to the cartel of buyer acceptance of or resistance to a price increase acceptance avoids costly market share reallocations among members of an explicit cartel logit estimates show that after 1985 the likelihood of a price announcement is largely driven by the length of time between announcements rather than cost or demand factors suggesting that the price announcements after 1985 stem from cartel meetings

oligopolistic competition as a common agency game oligopolistic competition is analyzed in a complete information multi principal common agency framework where principals are firms supplying differentiated goods and the agent is a representative consumer we first propose a canonical formulation of common agency games and a parameterization of the set of equilibria based on the lagrange multipliers associated with the participation and the incentive compatibility constraints of each principal this is used to characterize the set of equilibria in the intrinsic and non intrinsic games the former includes the latter as well as the standard price and quantity equilibrium outcomes it may also include the collusive solution

how much do incentives affect car purchase agent based microsimulation of consumer choice of new cars part i model structure simulation of bounded rationality and model validation this article presents an agent based microsimulation capable of forecasting the effects of policy levers that influence individual choices of new passenger cars the fundamental decision making units are households distinguished by sociodemographic characteristics and car ownership a two stage model of individual decision processes is employed in the first stage individual choice sets are constructed using simple non compensatory rules that are based on previously owned cars second decision makers evaluate alternatives in their individual choice set using a multi attributive weighting rule the attribute weights are based on a multinomial logit model for cross country policy analysis in european countries additionally prospect theory and the notion of mental accounting are used to model the perception of monetary values the microsimulation forecasts actual market observations with high accuracy both on the level of aggregate market characteristics as well as on a highly resolved level of distributions of market shares the presented approach is useful for the assessment of policies that influence individual purchase decisions of new passenger cars it allows accounting for a highly resolved car fleet and differentiated consumer segments as a result the complexity of incentive schemes can be represented and detailed structural changes can be investigated

vertical price controls with uncertain demand a manufacturer distributes output before knowing demand and thus risks making more than its rivalrous independent retailers can sell at the monopoly price if demand is low retailers may therefore resell more than the joint profit maximizing output anticipating this they will not pay as much for the merchandise ex ante as they would if the manufacturer could commit to preventing rivalry the manufacturer has many options including vertical integration chain outlets restricted output buy backs just in time deliveries and minimum resale prices the article discusses each option s advantages and disadvantages and concludes that all roads lead to resale price maintenance the article closes with an alternative to the dealercartel hypothesis for minimum resale prices

competition advertising and meeting competition clauses abstract pricing according to meeting competition clauses mcc s is often argued to enforce collusive agreements our analysis incorporates uncertainty and advertising we show within a spatial model that mcc s permit price discrimination but at the expense of lower profits

how do foreign firms patent in emerging economies with weak appropriability regimes archetypes and motives abstract foreign firms patent in emerging economies with weak appropriability regimes at an increasing rate this phenomenon constitutes a paradox since in such a setting foreign firms should have weak incentives to patent in an attempt to resolve this paradox we conducted an inductive analysis of 11 foreign firms that patent in such a setting using the case of china as our empirical context we identify four archetypes of foreign firms and three key antecedents the interaction of which determines which archetype a firm can be subsumed under our study complements the developed economy focus of the extant appropriation literature by adding an international perspective we extend previous econometric studies by identifying salient factors on the firm level that determine the extent to which a foreign firm patents in emerging economies with a weak appropriability regime highlighting that the extent of a firm s motivation to maintain its freedom to operate can supersede imitability concerns we also comment on the practical implications of these contributions for managers of foreign firms highlighting a structural conflict of interest between foreign firms from developed economies and the development goals of an emerging economy we point to the generalizability of our results to a wide range of other emerging economies worldwide

how much do incentives affect car purchase agent based microsimulation of consumer choice of new cars part ii forecasting effects of feebates based on energy efficiency abstract in this paper we simulate the car market in order to forecast the effects of feebate systems based on an energy labeling scheme using categories a to g very fuel efficient a cars receive a cash incentive highly inefficient g cars pay additional fees consumers have different price elasticities and behavioral options to react to feebates they can switch to a smaller sized car but as energy efficiency varies widely within size segments they can also stick to the preferred size class and choose a more efficient smaller engine in addition previously owned cars influence the next car to be chosen we use an agent based microsimulation approach particularly suited to predict environmental and market effects of feebates heteorogenous agents choose from a choice set drawn from a detailed fleet of new cars incentives of 2000 for a labeled cars induce an additional rated co 2 emission decrease of new car registrations between 3 4 and 4 3 with co 2 abatement costs between 6 and 13 per ton and otherwise little undesired market disturbance the risk of rebound effects is estimated to be low after adopting the frequencies of consumer segments to a given country the model presented is applicable to all european car markets

general equilibrium concepts under imperfect competition a cournotian approach in a pure exchange economy we propose a general equilibrium concept under imperfect competition the cournotian monopolistic competition equilibrium and compare it to the cournot walras and the monopolistic competition concepts the advantage of the proposed concept is to require less computational ability from the agents the comparison is made first through a simple example then through a mon abstract concept the p equilibrium based on a general notion of price coordination c 1997 academic press

technological regimes and industrial dynamics the evidence from dutch manufacturing previous empirical research has shown that the observed inter sectoral variety in the rates and form of organizations of innovations is related is related to the differences in the underlying technological regimes further theoretical models of industry dynamics suggest a similar relationship between the structural and dynamic properties of the firm population of an industry and its underlying technological regime using productivity differences between entrants and incumbents as a proxy for the technological regime of an industry this paper on the grounds of longitudinal firm level database on the dutch manufacturing sector shows that differences between industries with regard to their structural and dynamic properties are strongly related to their underlying technological regimes

cournot and the oligopoly problem cournot s recherches sw les principes mathpmatiques de la thiorie des richesses 1838 contribution to economic theory ranges from the formulation of the concept of demand function to the analysis of price determination in different market structures from monopoly to perfect competition he is credited for being the pioneer in the use of mathematics in economic analysis nevertheless cournot is most known for his theory of oligopoly cournot claimed that prices would also be determined under oligopolistic rivalry he envisioned firms the celebrated mineral water producers competing independently deciding about their production levels and bringing to the market the output where a price emerges from the interaction of supply and demand an equilibrium is reached when the output of any firm is a best response to the other firms outputs that is when each firm chooses an output level that maximizes profits given the outputs chosen by the rivals the equilibrium involves a price above the marginal cost of production cournot thought furthermore that this equilibrium would be stable in the sense that a departure from it would be self correcting through a series of reactions of the firms the disequilibrium dynamics would be governed by the best response functions of the firms that is by the functions that give the optimal output of a firm in terms of the outputs of the rivals cournot also evoked the question of why is it that firms do not come to an understanding and agree on sharing the market at the monopoly price the answer is that from the point of view of a firm if the rivals follow the agreement it is in the interest of the firm to depart from it since this way it can increase its profits in other words there is an incentive to cheat cournot thought that monopoly or cartel type agreements could only be maintained by means of a formal engagement p 83 our author also considered competition of

the most favored nation pricing policy and negotiated prices previous work has viewed the most favored nation mfn contract as a practice capable of facilitating collusion among sellers but this paper shows that even a monopoly seller may gain by including the mfn provision in sales contracts we consider a case in which the seller negotiates price separately with each of two buyers by including a mfn clause in her contract with the first buyer the seller raises her cost of granting price concessions to the second buyer this increases the seller s bargaining strength with respect to the second buyer thereby helping her negotiate a higher price

identifying the influencing factors of the sustainable energy transitions in china abstract this paper aims to explore the influencing factors that facilitate sustainable energy transitions in china for this purpose this paper assumes that the impact of the energy transition is from three main factors energy technology innovations the energy market and socio technical regimes which can be subdivided into 11 subfactors to empirically test the proposed hypotheses questionnaire survey data collected from chinese energy enterprises are statistically analysed by structural equation models sems the results show that first energy technology innovations the energy market and socio technical regimes are the major forces in the transition to sustainable energy in china second the effects of the three main factors on the energy transition vary according to 11 different subfactors some subfactors i e innovation strategy innovation factors innovation policy innovation network and new energy competitiveness have very important positive effects on the energy transition some subfactors i e competitiveness of the coal industry customer habits and coal based infrastructure have negative effects on the transition to sustainable energy in china third the influence of the subfactors on the transition performance is diminished as a result of the joint intermediate effects of transition behaviours

cooperative r d and vertical product differentiation abstract a partial equilibrium model with vertical product differentiation coumot competition and quality determined by r d expenses is analysed cooperative agreements on r d entail higher levels of r d quality output and welfare than at the non cooperative equilibrium under well denned conditions on spillover rates this confirms in a new setting a well known outcome of models with cost reducing r d further cooperation in r d allows a larger number of firms to operate in the industry than in the non cooperative case via a reduction in prices a new source of social gains from cooperative research is identified

equilibrium incentives for most favored customer clauses in an oligopolistic industry abstract this paper analyzes the economics of contemporaneous most favored customer clauses mfcc in a non cooperative n firm oligopoly in the first stage of a two stage game each firm independently decides whether to adopt mfcc in the second stage firms set prices non cooperatively given the first stage choices in contrast to work on retroactive mfcc by cooper the rand journal of economics 1986 17 377 388 our analysis shows that not adopting mfcc can be a dominant strategy the difference between our results and cooper s highlights important differences between retroactive and contemporaneous mfcc and suggests that mfcc are a less powerful facilitating practice than retroactive mfcc our analysis also sheds new light on grether and plott s economic inquiry 1984 22 497 507 experimental results regarding the effects of mfcc on average industry prices

list pricing and discounting in a bertrand edgeworth duopoly list or retail pricing is a widely used trading institution where firms announce a price that may be discounted at a later stage competition authorities view list pricing and discounting as a procompetitive practice we modify the standard bertrand edgeworth duopoly model to include list pricing and a subsequent discounting stage both firms first simultaneously choose a maximum list price and then decide whether to discount or not in a subsequent stage we show that list pricing works as a credible commitment device that induces a pure strategy outcome this is true for a general class of rationing rules further unlike the dominant firm interpretation of a price leader the low capacity firm may have incentives to commit to a low price and in this sense assume the role of a leader

the effects of price restrictions on competition between national and local firms i present a game theoretic model of competition between a national firm and local firms in which the introduction of most favored customer clauses into the sales contracts of the national firm decreases all industry prices the reason is that the price restriction makes the national firm a weak price competitor in each local market this produces a prisoners dilemma situation in which each local firm has the unilateral incentive to be more aggressive in nonprice decisions this increase in nonprice competition by all local firms causes prices to fall across the industry

on the existence of cournot equilibrium this paper examines the existence of n firm cournot equilibrium in a market for a single homogeneous commodity it proves that if each firm s marginal revenue declines as the aggregate output of other firms increases which is implied by concave inverse demand then a cournot equilibrium exists without assuming that firms have nondecreasing marginal cost or identical technologies also if the marginal revenue condition fails at a potential optimal point there is a set of firms such that no cournot equilibrium exists the paper also contains an example of nonexistence with two nonidentical firms each with constant returns to scale production