Some Implications of Imperfect Competition For Recent Trade Theory*

This paper argues that in a general-equilibrium context, it is not sensible for oligopolistic (and mono-polistically competitive) firms to maximize profit, because the outcome would be sensitive to the choice of the numeraire. the natural objective of these firms would be to maximize the utility of the shareholders if the shareholders are identical. I show that even if each firm takes the representative individual's marginal utility of income as given, the outcome of the utility maximization objective is Pareto optimal, and in equilibrium, each firm equates price with marginal cost.     

ON EQUILIBRIUM FOR OVERLAPPING GENERATIONS ORGANIZATIONS*

Necessary conditions for equilibrium are that beliefs about the behavior of other agents are rational and individuals maximize. We argue that in stationary OLG environments this implies that any future generation in the same situation as the initial generation must do as well as the initial generation did in that situation. We conclude that the existing equilibrium concepts in the literature do not satisfy this condition. We then propose an alternative equilibrium concept, organizational equilibrium that satisfies this condition. We show that equilibrium exists, it is unique, and it improves over autarky without achieving optimality. Moreover, the equilibrium can be readily found by solving a maximization program.     

Price competition,free entry,and welfare in congested markets

In this paper we study the problem of price competition and free entry in congested markets. In particular, we consider a network with multiple origins and a common destination node, where each link is owned by a firm that sets prices in order to maximize profits, whereas users want to minimize the total cost they face, which is given by the congestion cost plus the prices set by firms. In this environment, we introduce the notion of Markovian Traffic Equilibrium to establish the existence and uniqueness of a pure strategy price equilibrium, without assuming that the demand functions are concave nor imposing particular functional forms for the latency functions. We derive explicit conditions to guarantee existence and uniqueness of equilibria. Given this existence and uniqueness result, we apply our framework to study entry decisions and welfare, and establish that in congested markets with free entry, the number of firms exceeds the social optimum.     

Strategic managerial incentives in a two-period Cournot duopoly

This paper examines the nature of optimal managerial incentives in the context of a duopoly marked by competition between the firm's managers in a dynamic production environment. If the marginal cost of production falls moderately over time or remains unchanged, there exists an equilibrium where one owner requires her manager to maximize profit, whereas the rival-owner requires her manager to maximize sales revenue. The profit-maximizing manager turns his firm into a Stackelberg-leader, while the sales-revenue-maximizing manager turns his firm into a Stackelberg-follower. Further, the profit-maximizing manager may generate a larger firm profit relative to the sales-revenue-maximizing manager.     

Internal bargaining and strategic innovation in the theory of the firm

The transaction cost analysis of the firm has identified asset idiosyncrasy and the risk of ex post opportunism as key determinants of organizational form. Simultaneously, several writers have modeled the distribution of quasi-rents among input suppliers as a bargaining game. These complementary ideas are used to formalize the notion of strategic innovation, where capital and labor attempt to redistribute firm income after specialized assets are in place, through unilateral modifications in production technology. Because strategic behavior can enlarge the quasi-rent component of fifirm income, this process may persist in equilibrium. Asset idiosyncrasy therefore creates room for an autonomous theory of organizational dynamics, partially insulated from events at the market level of analysis.     

On optimality in intergenerational risk sharing

Summary. This paper defines and studies optimality in a dynamic stochastic economy with finitely lived agents, and investigates the optimality properties of an equilibrium with or without sequentially complete markets. Various Pareto optimality concepts are considered, including interim and ex ante optimality. We show that, at an equilibrium with a productive asset (land) and sequentially complete markets, the intervention of a government may be justified, but only to improve risk sharing between generations. If markets are incomplete, constrained interim optimality is investigated in two-period lived OLG economies. We extend the optimality properties of an equilibrium with land and give conditions under which introducing a pay-as-you-go system at an equilibrium would not lead to any Pareto improvement. Received: October 5, 1998; revised version: April 3, 2001     

Monopolistic competition and optimum product selection: Why and how heterogeneity matters

After some decades of relative oblivion, the interest in the optimality properties of monopolistic competition has recently re-emerged due to the availability of an appropriate and parsimonious framework to deal with firm heterogeneity. Within this framework we show that non-separable utility, variable demand elasticity and endogenous firm heterogeneity cause the market equilibrium to err in many ways, concerning the number of products, the size and the choice of producers, the overall size of the monopolistically competitive sector. More crucially with respect to the existing literature, we also show that the extent of the errors depends on the degree of firm heterogeneity. In particular, the inefficiency of the market equilibrium is largest when selection among heterogenous firms is needed most, that is, when there are relatively many firms with low productivity and relatively few firms with high productivity.     

Nonconvergent Electoral Equilibria under Scoring Rules: Beyond Plurality

We use Hotelling's spatial model of competition to investigate the position‐taking behavior of political candidates under a class of electoral systems known as scoring rules, though the model also has a natural interpretation in the firm location context. Candidates choose ideological positions so as to maximize their support in society. Convergent Nash equilibria in which all candidates adopt the same policy were characterized by Cox (1987). Here, we investigate nonconvergent equilibria, where candidates adopt divergent policies. We identify a number of classes of scoring rules exhibiting a range of different equilibrium properties. For some of these, nonconvergent equilibria do not exist. For others, nonconvergent equilibria in which candidates cluster at positions spread across the issue space are observed. In particular, we prove that the class of convex rules does not have Nash equilibria (convergent or nonconvergent) with the exception of some derivatives of Borda rule. We also look at “two‐party” equilibria. Implications for the firm location model are discussed.     

The price normalization problem in imperfect competition and the objective of the firm

Summary. General equilibrium models of oligopolistic competition give rise to relative prices only without determining the price level. It is well known that the choice of a numéraire or, more generally, of a normalization rule converting relative prices into absolute prices entails drastic consequences for the resulting set of Nash equilibria when firms are assumed to maximize profits. This is due to the fact that changing the price normalization amounts to altering the objective functions of the firms. Clearly, the objective of a firm must not be based on price normalization rules void of any economic content. In this paper we propose a definition of the objective of a firm, called maximization of shareholders' real wealth, which takes shareholders' demand explicitly into account. This objective depends on relative prices only. Real wealth maxima are shown to exist under certain conditions. Moreover, we consider an oligopolistic market and prove the existence of a Nash equilibrium in which each firm maximizes the real wealth of its shareholders. Received: July 10, 1997; revised version: July 27, 1998     

Informative advertising by heterogeneous firms

This paper introduces a model to analyze the role of the cost of information dissemination in large markets where firms have varying degrees of intrinsic efficiency reflected in their marginal costs. Firms enter a market and discover how efficient they are. Those firms with high enough efficiency stay, others exit. Remaining firms then compete to attract consumers by disseminating information about their existence and their prices using a common advertising technology. The properties of the model’s equilibrium are analyzed. The model is then used to study the effect of the cost of information dissemination on the competitiveness of the market and key industry aggregates, such as price distribution and the distribution of firm value.     

Equilibrium in economies with incomplete financial markets

This paper analyses an exchange economy in the absence of Arrow-Debreu complete markets. It is assumed that trading takes place in the sequence of spot markets and futures markets for securities payable in units of account. Unlimited short-selling in securities is allowed. A general equilibrium in such an economy is a set of current and future prices (contingent on uncertain events) and a set of individual plans such that all markets are cleared. The existence of such an equilibrium is proved under usual assumptions. This is in contrast to the case of futures markets for contingent futures commodities where an equilibrium may not exist. The optimality of equilibrium allocations is also discussed.     

Worker Absenteeism in Search Equilibrium*

In this paper we introduce a general equilibrium model of search unemployment that incorporates absence from work as a distinct labor force state. Absenteeism is driven by random shocks to the value of leisure that are private information to the workers. Firms maximize profits while recognizing that the compensation package may affect the queue of job applicants and the absence rate. The analysis provides results concerning the effects of social insurance benefits and other determinants of workers' and firms' behavior. The normative analysis identifies externalities associated with firm‐provided sick pay and examines the welfare implications of alternative policies.     

Electoral Systems, Legislative Process, and Income Taxation

We characterize the equilibrium income tax schedules and the optimality conditions under two types of political institutions, a two-party plurality system with a single district, and one with multiple districts where tax policies are determined through a legislature. It is shown that the exogenous social welfare functions in the optimal taxation literature can be endogenously determined by explicitly modeling the political institutions, which put different welfare weights on different subsets of the population. This paper also extends the Coughlin probabilistic voting model and the Baron–Ferejohn legislative bargaining model to a function space.     

Aggregate savings when individual income varies

This paper examines aggregate savings in a general equilibrium model where infinitely lived households face volatile (and possibly uncertain) income paths, hold a risk-free asset, and face a borrowing constraint. I first show that the equilibrium capital stock in an economy without uncertainty, but where individual income varies, can be larger than in an economy where each household's income is constant. When individual income is stochastic and uninsurable, the equilibrium capital stock is always larger than when income is constant. This additional capital accumulation has sometimes been interpreted as precautionary savings, but I argue that much of the additional savings are generated by permanent-income motives in combination with strict borrowing constraints.     

A Pure Theory of Job Security and Labour Income Risk

Models of labour market equilibrium where forward-looking decisions maximize both profits and labour income on a risk-neutral basis offer valuable insights into the effects of employment protection legislation. Since risk-neutral behaviour in the labour market presumes perfect insurance, however, job security provisions plays no useful role in such models. This paper studies a stylized model of dynamic labour market interactions where labour reallocation costs are partly financed by uninsured workers' consumption flows. In the resulting second-best equilibrium, provisions that shift labour reallocation costs to risk-neutral employers can increase productive efficiency if their administrative dead-weight costs are not too large, and increase workers' welfare as long as employers' firing costs at least partly finance workers' mobility.     

Price search and spatial competition

In this paper we study a model where two spatially scattered sellers face a population of consumers dispersed over a given geographical area; they have to incur a transaction cost to place their purchase order. Moreover these consumers have imperfect knowledge of prices, but obtain full information about prices at the first shop they solicit. We study price competition between these firms. The main outcomes of our analysis are as follows. First we show that whenever a price equilibrium exists for given locations of firms, it will necessarily display price dispersion. Second we study location configurations which ensure the existence of a price equilibrium. Furthermore we show that when it exists, a price equilibrium is unique. Finally we analyze firms revenues when merchants anticipate the consequences of their locational choice on subsequent price competition. Then we find that there is an incentive for a firm to get as close as possible to its competitor.     

Taxes,Strikes and Wages

A union and a firm bargain about wage increases. The firm possesses private information about its revenues. A two-period screening model is used to derive equilibrium wage demands by the union and to calculate measures of strike activity. Changes in wage demands and dispute probabilities due to alterations in various taxes are analysed. A more progressive income tax, a lower level of income taxes and higher payroll taxes reduce wages and strike activity. Hence, tax policy can be used not only to affect wages and employment, but lso to influence strike incidence.     

Estate taxes, consumption externalities, and altruism

We study how the introduction of consumption externalities affects the optimality of the dynamic equilibrium in an economy displaying dynastic altruism. When the bequest motive is inoperative consumption externalities affect the intertemporal margin between young and old consumption and thus modify the intertemporal path of aggregate consumption and capital. The optimal tax policy that solves this intertemporal suboptimality consists of a tax on capital income and a pay-as-you-go social security system. The latter solves the excess of capital accumulation due to the inoperativeness of the bequest motive and the former solves the suboptimal allocation of consumption due to consumption externalities. When the bequest motive is operative consumption externalities only cause an intratemporal misallocation of consumption but do not affect the optimality of the capital stock level. This suboptimal allocation of consumption implies in turn that the path of bequest deviates also from optimality. The optimal tax policy in this case consists of an estate tax and a capital income tax.     

Multiple attractors and global bifurcations in a Kaldor-type business cycle model

We consider a Kaldor-type discrete-time nonlinear business cycle model in income and capital, where investment is assumed to depend both on the difference between normal and current levels of capital stock, and on the difference between the current income and its normal level, through a nonlinear S-shaped increasing function. As usual in Kaldor business cycle models, one or three steady states exist, and the standard analysis of the local stability and bifurcations suggests that endogenous oscillations occur in the presence of only one unstable equilibrium, whereas the coexistence of three equilibria is characterized by bi-stability, the central equilibrium being on the boundary which separates the basins of the two stable ones. However, a deeper analysis of the global dynamic properties of the model in the parameter ranges where three steady states exist, reveals the existence of an attracting limit cycle surrounding the three steady states, leading to a situation of multistability, with a rich and complex dynamic structure.     

On the efficiency of fixed price equilibrium

We study the efficiency properties of K-equilibrium, a species of fixed price equilibrium. In particular, we examine the interrelations among K-equilibria and two of its properties: order and voluntariness. We also consider several alternative concepts of optimality.