產業經濟學英文版課件(已修改)

　

【正文】 Chapter 1: Introduction ? Applied Microeconomics ? Applied microeconomics: Any application of microeconomic models to the real world ? – Econometrics often used to assess data ? Some fields in applied microeconomics: ? – Industrial anization ? Chapter 1 Introduction: ? Industrial Organization Chapter 1: Introduction ? – Urban economics ? – Economics of education ? – Labor economics Chapter 1: Introduction ? IO: Industrial Organization ? ? Industry: Any largescale business activity ? – Steel ? – Hotels ? – Banking ? ? IO: Study of firm behavior, the overall structure of markets, and the implications on the welfare of consumers, producers, and efficiency Chapter 1: Introduction ? Some Sample Questions in IO ? ? Do markets with fewer firms have higher prices? Worse products? ? ? What affects nature of products offered? ? ? Why do we observe huge profits in an industry but no new firms entering? ? ? Can existing firms keep out new petitors? When would they want to? ? ? When should government allow mergers? Chapter 1: Introduction ? Market Power ? ? Two simple models of firm behavior: ? – Perfect petition: Model predicts p = mc ? – Monopoly: Model predicts p mc ? ? Market power: Ability of a firm to charge a price above marginal costs ? – Does a monopolist have market power? ? ? Industrial anization studies markets where firms have some market power Chapter 1: Introduction ? Perfect Competition Supply side of the market Demand side of the market Chapter 1: Introduction ? Supply Curve Gone ? ? Beyond model of perfect petition there ? is no simple market supply curve ? – Already familiar with this idea as there is no ? supply curve in a monopoly market ? ? In this course, find market equilibrium for ? models where firms have market power ? – This will not be an exercise in finding an ? intersection of supply and demand as we ? must consider strategic behavior of firms Chapter 1: Introduction ? Supply Side ? ? Assume each firm behaves in a way ? consistent with profit maximization ? – Firm will make decisions such that marginal ? revenue (MR) = marginal cost (MC) ? – Assume firm knows demand and its costs ? ? Possible choice variables include: price, ? quantity, advertising, quality, product ? characteristics, terms of sale (rent or sell) Chapter 1: Introduction ? Demand Side ? All of the models we will study depend ? critically on demand ? – Market demand if no price discrimination ? – Individual demand or market segment ? demand if price discrimination ? ? “Suppose demand is P = 100 – 2Q” ? – How to find demand parameters: 100 and 2? ? – Answer: Data collection and econometrics Chapter 1: Introduction ? Two Branches of IO ? Theoretical IO: Derive predictions using ? microeconomic theory and a set of ? plausible assumptions ? – Focuses on mathematical derivations ? ? Empirical IO: Use data to estimate the ? parameters of a theoretical model ? – Focuses on proper data collection and ? econometric techniques Chapter 1: Introduction ? Theoretical IO: Simple Example ? Suppose a market is perfectly petitive ? – Market demand: P = a – bQ ? – Market supply: P = c + dQ ? ? Find intersection of supply and demand: ? Q* = (a – c) / (b + d) ? ? Comparative statics analysis: Comparison ? of two different equilibrium states, before ? and after a change Chapter 1: Introduction ? Empirical IO ? ? Reduced form analysis: Find empirical ? relationship between economic variables ? – Estimated equation cannot be interpreted as a ? causal relationship: shows only correlations ? not causation ? ? Structural model: A model derived from ? economic theory ? – Estimated equation can be interpreted as a ? causal relationship Chapter 1: Introduction ? Empirical IO: Simple Example ? ? Write down a structural model and ? estimate demand and supply parameters: ? P = a – bQ + ε ? P = c + dQ + ε ? ? We will see in Lectures 4 and 5 this is not ? as simple as running a regression ? – Will learn some econometric techniques to ? obtain unbiased parameter estimates Chapter 1: Introduction ? Role of Theory and Empirics ? ? Theoretical IO important ? – Provides a foundation for empirical work ? – Useful theoretical results even without data ? ? Ex: Predict that a monopolist would choose to rent rather than sell a durable good to maximize profits ? ? Empirical IO important ? – Quantify effects predicted by theory ? ? Ex: Determine that prices would increase 4% with ? a merger of two petitors Chapter 1: Introduction Chapter 1: Introduction Chapter 1: Introduction ? SCP: Empirical Work ? ? Find general empirical relationships ? between structure and performance ? ? Relies on accounting data on profits and ? costs to measure market power ? – Crosssectional data for different industries ? – Run regressions: ? ? Dependent variable measures industry profitability ? (market performance) and independent variable ? measures concentration (market structure) Chapter 1: Introduction ? New Industrial Organization ? ? Focuses on specific industries ? – Analyze each industry individually ? ? Models strategic behavior by firms using ? microeconomic theory (aka price theory) ? ? Identifies exogenous factors: primitives ? – Exogenous: Not affected by firms? behavior ? ? Determined by things outside the model ? – Endogenous: Affected by firms? behavior Chapter 1: Introduction Chapter 1: Introduction ? New Empirical IO ? ? Regressions and other econometric ? analyses have foundation in micro theory ? – Structural models ? ? Not reduced form analysis like empirical SCP ? – Timeseries data or crosssectional data over ? different geographic areas