【導(dǎo)讀】–Urbaneconomics. –Laboreconomics. –Steel. –Hotels. –Banking. prices?Worseproducts?MarketPower. PerfectCompetition. SupplyCurveGone. SupplySide. revenue(MR)=marginalcost(MC). quantity,advertising,quality,product. characteristics,termsofsale(rentorsell). DemandSide. criticallyondemand. “SupposedemandisP=100–2Q”。TwoBranchesofIO. –Marketdemand:P=a–bQ. –Marketsupply:P=c+dQ. Q*=(a–c)/(b+d). andafterachange. EmpiricalIO. Reducedformanalysi

　　

【正文】 both” Chapter 5: Monopolization and Predatory Pricing ? Is Firm Dominant? Monopolist? ? ? Before claiming a firm monopolizing a market through bad acts or abusing a dominant position, must know market ? – Must delineate the antitrust market: group of ? products and geographic area ? ? Blind application of the hypothetical monopolist test does not make sense ? – Mergers: Would market power be created? ? But here: Does market power exist? Chapter 5: Monopolization and Predatory Pricing ? A ProfitMaximizing Monopolist ? ? Monopolist?s price always in elastic region ? – At monopoly price, demand is elastic: at that ? high price there are good substitutes ? – Posner: “Reasonable interchangeability at the ? current price but not at a petitive price ? level, far from demonstrating the absence of ? monopoly power, might well be a symptom of ? that power: this elementary point was ? pletely overlooked by the court” Chapter 5: Monopolization and Predatory Pricing ? Cellophane Fallacy ? ? Cellophane Fallacy: Name given to logical ? mistake of seeking to define a market by ? starting at prevailing monopoly prices and ? seeing if a SSNIP would be profitable (or ? looking for reasonable interchangeability) ? – How does following this false logic ensure that ? a monopolized antitrust market would never ? be found, no matter how much market power the monopolist has? Chapter 5: Monopolization and Predatory Pricing ? Correct Market Delineation ? ? The base price in the hypothetical ? monopolist test should be the petitive ? price not the prevailing price ? – Prevailing price already inflated through ? exercise of market power ? – Competitive price is marginal cost ? – Hence the SSNIP is relative to the petitive ? price Chapter 5: Monopolization and Predatory Pricing ? Economic Definition of Predation ? ? Predation: Behavior by a firm that is only ? profitable if it causes a petitor to exit ? the market ? ? Want to distinguish fierce petition from ? predation ? – Both may result in exit of a petitor ? – But, fierce petition is profitmaximizing ? whether or not petitors exit Chapter 5: Monopolization and Predatory Pricing ? Complaining Competitors ? ? Most lawsuits alleging predatory pricing ? are brought by peting firms ? ? But maybe these plaining firms are ? simply inefficient and think that such low ? prices could not be above marginal costs ? when in fact they are ? – Competitors might try to use antitrust laws to ? shield themselves from tough petition ? ? Firms might bee afraid to seek to lower costs! Chapter 5: Monopolization and Predatory Pricing ? Predation Tests ? ? AreedaTurner Test: Predatory prices are ? below shortrun marginal cost ? – Recognized importance of marginal costs and ? discredited tests based on average total costs ? ? Published 1975 in Harvard Law Review ? ? Baumol Test: Predatory behavior does not ? cover avoidable costs ? ? Published 1996 Predation and the Logic of the ? Average Variable Cost Test Chapter 5: Monopolization and Predatory Pricing ? Avoidable Costs ? ? Avoidable costs: Costs that can be ? avoided/recovered by shutting down some ? or all production capacity ? – Includes any variable and/or fixed costs that ? can be avoided with the shutdown ? – Nonmarginal reductions in output ? ? Shut down: entire firm, one of several production ? facilities, retail locations or departments ? – Useful for multiproduct firms Chapter 5: Monopolization and Predatory Pricing ? Avoidable Cost Test Applied ? ? Competition Tribunal used avoidable cost ? agreed with Commissioner that: ? – Relevant unit of analysis: a flight ? – Other than overhead, virtually all costs ? avoidable ? – Costs avoidable in a period of one month ? – Average revenues per flight is the proper ? approach to measuring revenues ? ? Focus not on individual fares Chapter 5: Monopolization and Predatory Pricing ? Classic Chicago Attack ? ? Chicago school attack: predatory pricing ? would never occur because it?s not rational ? ? Summary of Chicago critique: ? – Predatory pricing to drive out rival only ? rational if predator can recoup losses ? ? Predator must follow predatory prices by high ? prices (substantially above costs) ? – Rivals know this so either will not exit, or will enter in future Chapter 5: Monopolization and Predatory Pricing Chapter 5: Monopolization and Predatory Pricing ? Rational Theories of Predation ? ? Long purse theory ? – Prey has less access to credit than predator ? ? Reputation models ? – Firm operates in multiple markets ? – Reputation for toughness that pays off in ? multiple markets ? ? Signaling models of predation Chapter 5: Monopolization and Predatory Pricing ? Predation in US: Supreme Court ? ? Supreme Court: two necessary conditions ? for a finding of predatory pricing: ? – Price below marginal cost (AreedaTurner ? test) ? – Firm is sufficiently likely to recoup its shortrun ? losses: predatory pricing is a rational strategy ? ? “Predatory pricing schemes are rarely ? tried, and even more rarely successful” Chapter 6: Market Structure and Market Power Chapter 6:Market Structure and Market Power: Cournot Intuition amp。 SCP Chapter 6: Market Structure and Market Power Basic Questions in IO ? What firms have market power? Quantify? – Possible measures of market power? ? What factors affect a firm?s ability to exercise market power? – Industry concentration? – Production technology (costs)? – Market size? – Entry/exit costs? Endogenous vs exogenous? Chapter 6: Market Structure and Market Power ? Pre