Empirical IO Learning Notes

 

Reference: Kohei K. (2023). ECON5630 Topics in Empirical Industrial Organization. Aguirregabiria, V. (2021). Empirical industrial organization: models, methods, and applications. University of To...

Reference:

  1. Kohei K. (2023). ECON5630 Topics in Empirical Industrial Organization.
  2. Aguirregabiria, V. (2021). Empirical industrial organization: models, methods, and applications. University of Toronto, Preliminary version.

Why I write this note? I have a research project with Professor Kohei Kawaguchi about Central Bank Digital Currency (CBDC). We are interested in the competition between CBDC and commercial banks. I am responsible for the empirical part of the project. Therefore, I need to learn some empirical IO methods. This note is a summary of my learning process. I will update this note regularly.

Keywords and definitions

  • What IO study is about? To understand the strategic interaction between firms in the market and its implications for market power and market structure.
  • Market power: the ability of a firm, or group of firms, to gain extraordinary profits above those needed to remunerate all the inputs at market prices.
    • Measurement: Lerner index, price-cost margin, markup.
  • Market structure: the number of firms in the market and the share of each firm, the products they sell.
    • Measurement: concentration ratio, Herfindahl-Hirschman Index (HHI).

What is given? What is to be determined?

  • The typical model in IO treats consumer demand, technology (or costs), and institutional features (beliefs) as given and studies how these exogenous factors determine endogenously market structure and firms market power.
  • Firms’ strategy: profit maximizing strategy;

Examples:

  • Perfect competition: firms take prices as given;
  • Perfect monopoly: firm takes demand as given;
  • Oligopoly: firms take each other’s strategies as given.

Empirical Industrial Organization (EIO) deals with the combination of data, models, and econometric methods to answer empirical questions related to the behavior of firms in markets.

Old EIO use industry-level data to estimate demand and cost functions. New EIO use micro-level data to estimate demand and cost functions.

In terms of data, variation is imporatnt. what are the main sources of sample variability in empirical studies in modern EIO?

  • Multiple products;
  • local markets;

Structure models

Structure models typically have compoents: 1) a model of consumer behavior or demand; 2) a specification of frims’ costs; 3) a static equailibrium model of firms’ competition in prices or quantities; 4) a dynamic equilibrium model of firms’ competition in prices or quantities; 5) a model of firm entry or exit in a market.

The parameters of the model are structural in the sense that they describe consumer preferences, production technology, and institutional constraints.