Buffl

Lecture 1

YL
by Yannick L.

how does the SSNIP Test work?

How the SSNIP Test Works:

  1. Select a Product and Geographic Area: Start with the product and geographic area in question.

  2. Consider a Price Increase: Hypothetically increase the price of the product by a small but significant amount (often 5-10%).

  3. Analyze Consumer Reaction: Assess whether a sufficient number of consumers would switch to other products or areas to make the price increase unprofitable for the hypothetical monopolist.

  4. Adjust the Market Definition: If the price increase is unprofitable because of consumer switching, the market definition is too narrow. It needs to be expanded to include substitute products or areas until the hypothetical monopolist could profitably impose the price increase.

Example:

Imagine a market for bottled water in a city. To determine the relevant market, we apply the SSNIP test:

  1. Initial Market: The market is "bottled water in City X."

  2. Price Increase: Assume the price of bottled water is increased by 5-10%.

  3. Consumer Reaction: Observe whether consumers switch to other sources of water (like tap water, flavored water, or water from nearby towns) in significant numbers.

  4. Adjustment:

    • If many consumers switch to tap water or flavored water, these alternatives are part of the same market. The market definition might be expanded to "drinking water in City X."

    • If consumers do not significantly switch, then the relevant market might remain "bottled water in City X."

The SSNIP test helps in determining the boundaries of a market for antitrust analysis, highlighting which products or areas are close substitutes from the consumer's perspective.

what is the K-firm concentration ratio?

The k-firm concentration ratio is a measure used in economics and antitrust analysis to assess the degree of market concentration. It indicates the combined market share of the top "k" firms in a particular market. This measure helps in understanding the competitive landscape of an industry, with a higher concentration ratio often indicating less competitive conditions.

Definition

The k-firm concentration ratio is calculated as the sum of the market shares of the top "k" firms in a market. If CRkCRk​ denotes the k-firm concentration ratio for the top kk firms, then:

CRk=Market Share of Firm 1+Market Share of Firm 2+⋯+Market Share of Firm kCRk​=Market Share of Firm 1+Market Share of Firm 2+⋯+Market Share of Firm k

Example

Suppose we have an industry with five firms, and their market shares are as follows:

  • Firm A: 30%

  • Firm B: 25%

  • Firm C: 20%

  • Firm D: 15%

  • Firm E: 10%

For different values of kk, the k-firm concentration ratios would be:

  • 2-firm concentration ratio (CR2): 30%+25%=55%30%+25%=55%

  • 3-firm concentration ratio (CR3): 30%+25%+20%=75%30%+25%+20%=75%

  • 4-firm concentration ratio (CR4): 30%+25%+20%+15%=90%30%+25%+20%+15%=90%

This means that the top 2 firms control 55% of the market, the top 3 firms control 75%, and the top 4 firms control 90%. A high concentration ratio (like CR3 or CR4 in this example) suggests that the market is oligopolistic, with a few firms dominating the market share. In contrast, a lower concentration ratio indicates a more competitive market structure.

Author

Yannick L.

Information

Last changed