# How do you calculate the Herfindahl Index?

## How do you calculate the Herfindahl Index?

You can calculate Herfindahl Index by squaring the market share for each firm (up to 50 firms) and then adding the squares. In a perfectly competitive market, HHI should approach zero.

## What does a high Herfindahl Index mean?

Increases in the Herfindahl index generally indicate a decrease in competition and an increase of market power, whereas decreases indicate the opposite. Alternatively, if whole percentages are used, the index ranges from 0 to 10,000 points.

## What is the highest possible Herfindahl Index?

The HHI value can range anywhere from near 0 up to 10,000. A higher index value means that the industry is considered to be closer to monopoly conditions. Generally, a market with an HHI value of under 1,000 is considered to be competitive.

## What is the Herfindahl Index of an oligopoly?

The Herfindahl-Hirschman Index, also called the Herfindahl Index, measures the extent to which market share is concentrated among a few or many companies. A Herfindahl-Hirschman Index score of about 2,500 suggests that the market has an ‘oligopoly’ it is controlled by very few companies. …

## What is the four-firm concentration ratio formula?

The four-firm concentration ratio is calculated by adding the market shares of the four largest firms: in this case, 16 + 10 + 8 + 6 = 40. … Then the four-firm concentration ratio is 16 + 10 + 8 + 6 = 40.

## What is the Herfindahl-Hirschman Index calculator?

HHI calculator The HHI calculator is a tool that easily computes the value of the Herfindahl-Hirschman Index. The HHI Index measures the market concentration (not capitalisation) of a particular industry and is used to determine market competitiveness.

## How do I find Rothschild index?

Rothschild Index

1. A measure of the elasticity of industry demand for a product relative to that of an individual firm: R = ET / EF
2. When an industry is composed of many firms, each producing similar products, the Rothschild index will be close to zero.

## How do you calculate cr4?

Add together the total sales for each of the four largest firms in your selected industry. Then divide that sum by the total sales of the industry. Convert that result to a percentage, and that percentage value is the four-firm concentration ratio.

## What is a highly concentrated market?

Definition: Market concentration is used when smaller firms account for large percentage of the total market. It measures the extent of domination of sales by one or more firms in a particular market. … If the top firms keep on gaining market share, then we say that the industry has become highly concentrated.

## What is a monopoly index?

Economists use the Lerner Index to measure monopoly power, also called market power. The index is the percent markup of price over marginal cost. (3.8) L = (P MC)/P. The Lerner Index is a positive number (L >= 0), increasing in the amount of market power.

## What is the Herfindahl index of a monopoly quizlet?

The Herfindahl Index is another measure of industry concentration and it is the sum of the squared percentage of market shares of all firms in the industry. Generally speaking, the lower the Herfindahl, the lower the industry concentration.

## What does a low HHI mean?

The Herfindahl-Hirschman Index is an index that measures the market concentration of an industry. … The lower the HHI is, the more power consumers hold in that industry. Thus, prices are usually lower, and company margins compressed.

## Why is HHI a better measure of competitiveness over CR?

Market concentration can be measured in different ways, i.e. by using different indicators. In the broadest use are the concentration ratio (CR) and Herfindahl-Hirschman Index (HHI). … It is believed that the Herfindahl-Hirschman Index is more precise measure because it takes into account all companies.

## How do you measure market concentration?

The most common measure to calculate the market concentration is the Herfindahl-Hirschman Index (HHI). This index is calculated by adding the square root of the percentage market share of each individual firm in the industry.

## What is an example of collusion?

Collusion occurs when rival firms agree to work together e.g. setting higher prices in order to make greater profits. … For example, vertical price-fixing e.g. retail price maintenance. (For example, Fixed Book Price (FBP) set the price a book is sold to the public.

## What is the Herfindahl index used for?

The Herfindahl-Hirschman Index (HHI) is a common measure of market concentration and is used to determine market competitiveness, often pre- and post-M&A transactions.

## What is CR4?

For example, the four-firm concentration ratio (CR4) refers to the market share of the four largest firms. … Equal to the sum of the squares of the market shares for the largest 50 firms in the industry. The higher the index, the more concentrated the industry.

## Why is the largest possible value of the Herfindahl index is 10000?

The largest possible value of the Herfindahl index is 10,000 because: An industry with an index higher than 10,000 is automatically regulated by the Justice Department An index of 10,000 corresponds to 100 firms with a 1% market share each An index of 10,000 corresponds to a monopoly firm with 100% market share.

## What is concentration ratio in economics?

The concentration ratio, in economics, is a ratio that indicates the size of firms in relation to their industry as a whole.

## How do you interpret the Lerner index?

Essentially, the index measures the percentage markup that a firm is able to charge over its marginal cost. The index ranges from a low value of 0 to a high of 1. The higher the value of the Lerner index, the more the firm is able to charge over its marginal cost, hence the greater its monopoly power.

## What does the Dansby Willig Performance Index measure?

Dansby-Willig Performance Index measure by how much social welfare would improve if firms in an industry expanded output in a socially efficient manner.

## When an industry is less concentrated the four firm concentration ratio is close to?

What do outcomes of the firms mean? The closer the four-firm concentration ratio is to zero, the less concentrated is the industry; the closer the ratio is to 1, the more concentrated is the industry. Concentration ratios provide a very crude measure of the size structure of an industry.

## What is CR4 and CR8?

The ratio commonly used is the concentration ratio of four companies (CR4). The ratio is the sum of the market share (S) of the four largest companies in an industry. In addition to CR4, the CR8 ratio is also commonly used to measure market concentration in the eight largest companies.

## Which industry has the highest concentration ratio?

Top 10 Highly Concentrated Industries

• Food Service Contractors – Top four market share: 93.2% …
• Lighting & Bulb Manufacturing – Top four market share: 91.9% …
• Tire Manufacturing – Top four market share: 91.3% …
• Major Household Appliance Manufacturing – Top four market share: 90.0%

## What is ppm in pharmacy?

Parts per million (ppm) is used to denote concentrations in cases when the ratio of ingredient to product is very small. It is equivalent to a ratio in the form of p in 1000000 or a fraction in which the denominator is 1000 000.

## What does it mean when a product is concentrated?

Things that are concentrated have been gathered together in the smallest possible bunch. If you use a concentrated cleaning product, you might need to mix it with water before using it. Concentrated often refers to a liquid solution that’s very strong, but it can describe anything that’s condensed into one area.

## What is a highly fragmented industry?

191. A fragmented industry is an industry with a large number of small or medium size firms where no firm has a significant market share or strong influence on the industry.

## What is a highly competitive market?

A competitive market is one where there are numerous producers that compete with one another in hopes to provide goods and services we, as consumers, want and need. In other words, not one single producer can dictate the market. Also, like producers, not one consumer can dictate the market either.