# 11.1 Corporate mergers  (Page 4/23)

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## Calculating hhi

Step 1. Calculate the HHI for a monopoly with a market share of 100%. Because there is only one firm, it has 100% market share. The HHI is 100 2 = 10,000.

Step 2. For an extremely competitive industry, with dozens or hundreds of extremely small competitors, the value of the HHI might drop as low as 100 or even less. Calculate the HHI for an industry with 100 firms that each have 1% of the market. In this case, the HHI is 100(1 2 ) = 100.

Step 3. Calculate the HHI for the industry shown in [link] . In this case, the HHI is 16 2 + 10 2 + 8 2 + 7(6 2 ) + 8(3 2 ) = 744.

Step 4. Note that the HHI gives greater weight to large firms.

Step 5. Consider the example given earlier, comparing one industry where five firms each have 20% of the market with an industry where one firm has 77% and the other 23 firms have 1% each. The two industries have the same four-firm concentration ratio of 80. But the HHI for the first industry is 5(20 2 ) = 2,000, while the HHI for the second industry is much higher at 77 2 + 23(1 2 ) = 5,952.

Step 6. Note that the near-monopolist in the second industry drives up the HHI measure of industrial concentration.

Step 7. Review [link] which gives some examples of the four-firm concentration ratio and the HHI in various U.S. industries in 2009. (You can find market share data from multiple industry sources. Data in the table are from: Verizon (for wireless), The Wall Street Journal (for automobiles), IDC Worldwide (for computers) and the U.S. Bureau of Transportation Statistics (for airlines).)

Examples of concentration ratios and hhis in the u.s. economy, 2009
U.S. Industry Four-Firm Ratio HHI
Wireless 91 2,311
Largest five: Verizon, AT&T, Sprint, T-Mobile, MetroPCS
Automobiles 63 1,121
Largest five: GM, Toyota, Ford, Honda, Chrysler
Computers 74 1,737
Largest five: HP, Dell, Acer, Apple, Toshiba
Airlines 44 536
Largest five: Southwest, American, Delta, United, U.S. Airways

In the 1980s, the FTC followed these guidelines: If a merger would result in an HHI of less than 1,000, the FTC would probably approve it. If a merger would result in an HHI of more than 1,800, the FTC would probably challenge it. If a merger would result in an HHI between 1,000 and 1,800, then the FTC would scrutinize the plan and make a case-by-case decision. However, in the last several decades, the antitrust enforcement authorities have moved away from relying as heavily on measures of concentration ratios and HHIs to determine whether a merger will be allowed, and instead carried out more case-by-case analysis on the extent of competition in different industries.

## New directions for antitrust

Both the four-firm concentration ratio and the Herfindahl-Hirschman index share some weaknesses. First, they begin from the assumption that the “market” under discussion is well-defined, and the only question is measuring how sales are divided in that market. Second, they are based on an implicit assumption that competitive conditions across industries are similar enough that a broad measure of concentration in the market is enough to make a decision about the effects of a merger. These assumptions, however, are not always correct. In response to these two problems, the antitrust regulators have been changing their approach in the last decade or two.

What is scarcity.
why our wants are limited
nooo want is unlimited but resources are limited
Ruchi
and do to that there occurs scarcity and we have to make choice in order to have what we need if need be I will explain more
our wants are not limited but rather the resources
Moses
as we know that there are two principle of microeconomics scarcity of resources and they have alternative uses...
Ruchi
yes .....
Mathias
what is demand
demand is something wt we called in economic theory of demand it simply means if price of product is increase then demand of product will decrease
Ruchi
inverse relationship between demand and price
Ruchi
in microeconomic
Ruchi
demand is what and how much you want and what's your need...
Shikhar
how can one be so with economics even while you have less knowledge in mathematics.
why is it that some products increases everyday by day
because demand is increase
Ruchi
because demand is increase
Patience
but how demand increases?
Aziz
Because of the Marketing and purchasing power of people.
AmarbirSingh
but how could we know that people's demands have increased everyday by day and how could we know that this is time to produced the products in the market. Is any connection among them
yaqoob
for normal good people demand remain the same if price of product will increase or not
Ruchi
see that some product which increases day by day is comes under normal good which is used by consumer
Ruchi
Seems hot discussing going here
Shamamet
If there are less products demand starts to increase for those products
Shamamet
Economics is really interesting to learn ....
Shamamet
see there is Inferior goods ands normal goods inferior good demand is rarely increase whereas as we talk about normal good demand will absolutely Increase whether price is increase or not
Ruchi
and demand for normal goods increase cause people's income as a while increases time to time
Abhisek
and it might also be that the cost of raw materials are high.
ATTAH
may be
Ruchi
obviously because demand is increasing.....and price is getting low.....
Shikhar
hmmm there is inverse relationship between demand and price
Ruchi
Importance of economics
the nature and significance of economics studies
Deborah
What is demand
deman is amount of goods and services a consumer is willing and able to buy or purchase at a given price.
Sainabou
the willingness and ability of a body to purchase goods nd servicesbis called demand ,so if she/has ability but doesn't have willingness it's not a demand same if she or he has willingness but doesn't has ability it's not a demand too
Gul
Demand refers to as quantities of a goods and services in which consumers are willing and able to purchase at a given period of time and demand can also be defined as the desire or willingness and backed by the ability to pay.
Yeah
Mathias
What is Choice
Kofi
Choice refers to the ability of a consumer or producer to decide which good, service or resource to purchase or provide from a range of possible options. Being free to chose is regarded as a fundamental indicator of economic well being and development.
Shonal
choice is a act of selecting or choosing from the numerous or plenty wants.
how does consumer make profit
Compare and contract the function of commercial bank and the central bank of Nigeria
what do think is the difference between overhead costs and prime cost
Abdoulkarim
what is economics
economics is a social science that study's how resources can be used to produce goods and services for society
Nathan
Economic is a science which studies human behavior as a relationship between ends and scares means which have alternatives uses or purposes.
what is economics
what is the basic economic problem
rules
unlimited wants vs limited resources
Nathan
what is a new paradigm shift
Paradigm shift it is the reconcilliation of fedural goods in production
Shyline
fedural? what is that?
Aziz
factors that affecting economic system
crux
Shyline