网络外部性、商业模式与PC市场结构

本文基于PC市场规模经济和网络外部性的特点 ,构建了扩展的豪泰林模型 ,研究了PC市场结构的决定因素和形成机理及厂商的不同商业模式 :在规模经济明显和网络外部性强的PC互补品市场上往往呈现出双寡头竞争格局 ,先进入PC市场的厂商较传统产业享有更大的成本优势和网络外部性优势 ,后来厂商不得不强化传统的价格和产品差异化等竞争手段 ,采取不同的商业模式参与竞争 ;在规模经济不明显和网络外部性弱的PC互补品市场往往呈现出多家企业进行垄断竞争的格局 ,双寡头市场上的厂商则根据不同的比较优势与垄断竞争市场的相关厂商进行合作或竞争。     

Does entry improve welfare? A general equilibrium approach to competition policy

We consider a simple general equilibrium model with imperfect competition. Firms are price takers in the input market and compete à la Cournot in some or all of the product markets and their technologies display constant returns to scale. We show that an increase in the number of firms in a given sector does not always improve welfare. We also provide a characterization in terms of mark-up rates of the sectors for which entry is welfare enhancing. Our results challenge the common idea that mergers with no cost synergy are not desirable for consumers.     

Pricing and capacity provision in electricity markets: an experimental study

The creation of adequate investment incentives has been of great concern in the restructuring of the electricity sector. However, to achieve this, regulators have applied different market designs across countries and regions. In this paper we employ laboratory methods to explore the relationship between market design, capacity provision and pricing in electricity markets. Subjects act as firms, choosing their generation capacity and competing in uniform price auction markets. We compare three regulatory designs: (1) a baseline price cap system that restricts scarcity rents, (2) a price spike regime that effectively lifts these restrictions, and (3) a capacity market that directly rewards the provision of capacity. Restricting price spikes leads to underinvestment. In line with the regulatory intention both alternative designs lead to sufficient investment albeit at the cost of higher energy prices during peak periods and substantial capacity payments in the capacity market regime. To some extent these results confirm theoretical expectations. However, we also find lower than predicted spot market prices as sellers compete relatively intensely in capacities and prices, and the capacity markets are less competitive than predicted.     

INSUFFICIENT ENTRY OF EMPLOYEE‐CONTROLLED FIRMS IN A FREE‐ENTRY OLIGOPOLY

This study is a theoretical examination of whether employee‐controlled firms (ECFs) enter a free‐entry oligopolistic market excessively or insufficiently, from the viewpoint of welfare maximization. The excess entry theorem is well known in oligopoly theory. According to this theorem, a greater number of profit‐maximizing firms enter a free‐entry oligopolistic market than is optimal for welfare maximization. We demonstrate the possibility that insufficient entry arises when ECFs compete in a free‐entry market. In particular, we show that if both the demand and cost functions are convex, insufficient ECF entry necessarily occurs. Our results suggest that competition among firms seeking purposes other than profit might lead to insufficient entry because differences in competing firms’ objectives affect the intensity of market competition.     

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.     

Exchange-rate pass-through and market structure

We consider a situation in whichn firms located in market 1 andm firms located in market 2 each sell a commodity which is homogeneous within each market but may differ between markets. All firms sell on both markets. Each market has its own currency. The market demand functions differ. We give some basic results on the effects of exchange-rate changes and then show the following. When these markets are independent on the cost side (constant marginal costs) and demands are linear, a reduction in the number of firms (which might result from a merger) in market 1 increases the pass-through (of an appreciation of currency 2) in market 1 and decreases the pass-through in market 2. A similar occurrence in market 2 has the opposite effect. We give conditions under which, with identical economies of scope linking the markets, the sign of the price changes will be reversed when the number of foreign firms is small enough compared to the number of local firms. However, such sign reversals cannot occur in the two markets simultaneously.     

Gains From Price Rigidity

This paper shows that there are substantial gains from price rigidity in an imperfectly competitive economy. Firms can increase their profits by agreeing some markets as markets of long-term contracts, of which prices are determined in advance to other spot market prices. Although they determine prices non-cooperatively in both markets, the mutual commitment making some markets' prices predetermined induces a price–price spiral between firms, which results in substantial gains for both firms. These gains outweigh the cost of inflexibility arising from price rigidity even though demand fluctuation is large and marginal cost is increasing.
JEL Classification Numbers: E30, E32.     

Exports, unemployment, and the welfare state

Abstract .  The paper analyzes the labour market effects of globalization when foreign market entry is costly and risky. With flexible labour markets, a fall in foreign market entry cost tends to generate more income inequality, but not necessarily so, as more firms pay foreign entry cost. By contrast, when labour markets are inflexible in the short run, globalization tends to increase unemployment. In this situation, government unemployment benefits reduce the wages that exporting firms need to pay workers as risk compensation. Thus more firms within an industry and more industries enter the foreign market, which in turn tends to increase unemployment.     

Horizontal mergers and product quality

We study the effects of a horizontal merger when firms compete on price and quality. In a Salop framework with three symmetric firms, several striking results appear. First, the merging firms reduce quality but possibly also price, whereas the outside firm increases both price and quality. As a result, the average price in the market increases, but also the average quality. Second, the outside firm benefits more than the merging firms from the merger, and the merger can be unprofitable for the merger partners, i.e., the “merger paradox” may appear. Third, the merger always reduces total consumer utility (though some consumers may benefit), but total welfare can increase due to endogenous quality cost savings. In a generalized framework with n firms, we identify two key factors for the merger effects: (i) the magnitude of marginal variable quality costs, which determines the nature of strategic interaction and (ii) the cross‐quality and cross‐price demand effects, which determines the intensity of price relative to quality competition. These findings have implications for antitrust policy in industries where quality is a key strategic variable for the firms.     

Preemptive entry in differentiated product markets

Summary. Models of spatial competition are typically static, and exhibit multiple free-entry equilibria. Incumbent firms can earn rents in equilibrium because any potential entrant expects a significantly lower market share (since it must fit into a niche between incumbent firms) along with fiercer price competition. Previous research has usually concentrated on the zero-profit equilibrium, at which there is normally excessive entry, and so an entry tax would improve the allocation of resources. At the other extreme, the equilibrium with the greatest rent per firm normally entails insufficient entry, so an entry subsidy should be prescribed. A model of sequential firm entry (with an exogenous order of moves) resolves the multiplicity problem but raises a new difficulty: firms that enter earlier can expect higher spatial rents, and so firms prefer to be earlier in the entry order. This tension disappears when firms can compete for entry positions. We therefore suppose that firms can commit capital early to the market in order to lay claim to a particular location. This temporal competition dissipates spatial rents in equilibrium and justifies the sequential move structure. However, the policy implications are quite different once time is introduced. An atemporal analysis of the sequential entry process would prescribe an entry subsidy, but once proper account is taken of the entry dynamics, a tax may be preferable. Received: April 26, 1999; revised version: September 22, 1999     

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.     

Rent‐Seeking,Market Structure,and Growth

We study the role of productive and unproductive entrepreneurship in economic growth, in a setting where firms compete in both economic and political markets. Specifically, firms compete for market share through cost‐reducing technological innovation, and they vie for influence over government transfer policy through rent‐seeking activities. We find that rent‐seeking affects growth in two ways: it allows firms to ignore economic competition, leading to less innovation, and it alters the number of firms that are supported in equilibrium. The former effect is negative, while the latter is ambiguous. We show how these effects depend on various characteristics of economic and political markets.     

The Political Economy of the (Weak) Enforcement of Indirect Taxes

The objective of this paper is to understand the determinants of the enforcement level of indirect taxation in a positive setting. We build a sequential game where individuals, who differ in their willingness to pay for a taxed good, vote over the enforcement level. Firms then compete à la Cournot and choose the fraction of sales taxes to evade. We assume in most of the paper that the tax rate is set exogenously. Voters face the following trade‐off: more enforcement not only increases tax collection but also increases the consumer price of the goods sold in an imperfectly competitive market. We obtain that the equilibrium enforcement level is the one most preferred by the individual with the median willingness to pay, that it is not affected by the structure of the market (number of firms) and the firms’ marginal cost, and that it decreases with the resource cost of evasion and with the tax rate. We also compare the enforcement level chosen by majority voting with the utilitarian level. In the last section, we endogenize the tax rate by assuming that individuals vote simultaneously over tax rate and enforcement level. We prove the existence of a Condorcet winner and show that it entails full enforcement (i.e., no tax evasion at equilibrium). The existence of markets with less than full enforcement then depends crucially on the fact that tax rates are not tailored to each market individually.     

寡占市场下的广告成因探究

依照微观经济学和产业组织理论,高度集中产业市场中的寡头厂商往往会在价格变量上形成暗中或默契的价格串谋,使产业市场处在一种“准完全垄断”的状态。广告是企业主要的非价格竞争变量之一,重复博弈的结果使得寡头厂商能够走出囚徒困境(放弃产品的广告宣传),而垄断利润的存在导致第三方潜在进入的威胁,在位寡头厂商必然会联合起来进行抵制,通过广告串谋提高市场进入壁垒。     

Costly Search, Capacity Constraints, and Bertrand Equilibrium Price Dispersion

This article analyzes the impact of transaction (search) costs and capacity constraints in an almost competitive market with homogeneous firms that compete on price. We characterize conditions under which Nash equilibria with price dispersion exist; in equilibrium, firms play pure strategies in prices and consumers adopt a symmetric mixed search strategy. Price dispersion is possible even though consumers all have the same search cost and valuation for the item and prices charged by all firms are common knowledge.     

Using the allocation of emission permits for strategic trade purposes

We show that the presence of transaction costs in emission permit markets challenges the common presumption that grandfathering permits corresponds to lump-sum transfers with no strategic effects on output. Fixed transaction-costs influence firms’ decision to participate in the permits market, while variable transaction-costs affect firms’ output choice by creating a wedge between buyers’ and sellers’ opportunity cost of using permits. Thus, permit grandfathering can be used as a strategic trade instrument even when firms are price takers in the permit markets. Grandfathered permits differ from subsidies in that the stimulus they provide is bounded exogenously and rather limited.     

THE IMPACT OF FOOD PRICE SHOCK ON HETEROGENEOUS CREDIT CONSTRAINED FIRMS

ABSTRACT 1 : The paper analyzes how rising food and energy prices affect heterogeneous firm access to inputs and production under credit market imperfections. We estimate a firm credit constraint equation using a unique firm level panel data and find that, on average, small individual firms (IF) are more credit constrained than large corporate firms (CF). Using the estimated parameters, we simulate the effect of the recent food price shock on the world markets. Our results suggest that in the presence of credit market imperfections, the less credit constrained CF benefit relatively more from food price increase than IF, as they are able to expand their production more flexibly. These findings have important policy implications for countries with significant market imperfections. In the case of the food price shock, not only consumers but also producers, which on average are more credit constrained than producers in developed countries, may lose their market shares and hence their income in the long run.     

EFFECTS OF ASYMMETRIC INFORMATION WITHIN A FIRM ON OLIGOPOLISTIC MARKET OUTCOMES

I analyze the implications of the Laffont–Tirole type agency problems on oligopolistic market outcomes. In the model, a firm's marginal cost is decreasing in managerial effort and is subject to an additive shock. Both managerial effort and the realization of the shock are a manager's private information. A firm first offers a menu of contract to its manager, and then competes in the product market. As in the model of single principal and single agent, the incentive contracts implement efforts that are distorted downward relative to full information. In this model, with multiple agency relationships, an additional source for upward distortion of effort emerges as a result of the interaction in the product market. The results are robust to whether firms compete in price or quantity.     

Endogenous market structures and the optimal financial structure

Abstract We characterize the optimal financial structure as a strategic device to optimize the value of a firm competing in a market where entry is endogenous. Debt financing is always optimal under quantity competition, and, contrary to the Brander‐Lewis‐Showalter results based on duopolies, we show the optimality of moderate debt financing also under price competition with cost uncertainty (but not with demand uncertainty). We derive the formulas for the optimal financial structure, which does not affect the strategies of the other firms but reduces their number.     

垄断竞争的电信业定价策略研究

讨论垄断竞争条件下电信业定价策略,对理解电信运营商的竞争行为、制定电信业竞争政策有重要的意义。本文将呼叫外部性引入模型,考察了呼叫方内部化接听方效用条件下企业定价策略,从而扩展了目前理论内容和结论。研究表明：当呼叫方内部化接听方的效用时,在线性定价条件下,电信运营商仍然会通过提高接入费进行合谋;在非线性定价条件下,由于电信运营商可以利用固定费进行市场份额的争夺,电信运营商不再有利用接入费进行合谋的动机;在基于终接网络的价格歧视条件下,当消费者接听效用接近于呼叫效用时,电信运营商将会通过制定无穷大的呼叫异网价格来获取更大的市场份额,因此网络联接发生了中断。