Basic Microeconomics by Professor R. Larry Reynolds, PhD - HTML preview

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profits. (Remember that normal profits are included in the cost functions as an

opportunity cost for the entrepreneur.) If the price falls below CB, the firm will

lose money, i.e. will earn less than normal profits. So long as the price is

above CC, the firm is recovering all the variable cost and a little more to offset

the fixed cost that it would have lost if the firm would have shutdown. At a

price of CC, the firm is recovering all its variable cost and losing its fixed cost

(which it would have done anyway if it had closed down.). Therefore, so long

as the firm can recover all its variable costs at a price of CC, it may as well

operate in the short run. Point C, at a price of CC and output of QC is called

247

12.2.1 Profit Maximization in the Short Run

the shutdown point. It will always be at the point where the MC intersects the

AVC (the minimum of the AVC).

In the long run all costs are variable, therefore the shut down point in the

long run is the minimum of the LRAC where MC= LRAC.

There may be other reasons for operating a production facility. In some

cases individuals may operate at less than normal profits because the get non-

monetary benefits from being in a particular line of work or being “their own

boss.” A government may encourage firms that produce particular products to

operate for reasons of national defense or national pride. In these cases public

policy may be used to subsidize the firms that would find it necessary to shut

down in a free market economy.

12.2.2 PROFITS IN LONG RUN PURE COMPETITION

I n the long run, producers are able to alter their scale of plant. The LRAC

or envelope curve was constructed from a series of short run periods with

different plant sizes. In the long run the firm is essentially able to select the

scale of plant (or a specific set short run production and cost functions

associated with a specific fixed (in the short run) input). The is essentially the

meaning of “relative ease of exit and entry from the market.

Another crucial aspect of long run pure competition is that the demand

faced by the firm is perfectly elastic at the market price. The AR and MR

functions coincide with the firm’s demand function. Because the firm’s demand

function is perfectly elastic, they cannot raise their price above the market

price. If they do, their sales will fall to 0. There is no reason to lower their

price below the market price because they can sell all they want to a the

market price. The firms in pure competition have no “market power. ” Market

power, in microeconomics, refers to the ability of an agent to raise the price

248

12.2.2 Profits in Long Run Pure Competition

and not have their sales fall to 0. A quick review of price elasticity suggests

that market power is influenced by a firm’s demand function. Purely

competitive firms are price takers. These firms have no incentive to advertise.

The largest producer in a purely competitive market can sell all they can

produce or none at all and the market price will be unaltered.

249

12.2.2 Profits in Long Run Pure Competition

LRMC

S

SRAC3

rice, $

SM

M*

rice, $

SRAC1

SRAC*

P

P

A

EM

SRAC2 B

D

P

f

EM

PEM

P*

ARf=MRf

P*

C

D*, AR*, MR*

DM

QEM

Qx(1027)

QA

QC QB

Qx/ut

Panel A.VII.6

Panel B.VII.6

(Market)

(Firm)

Figure VII.6

In Figure VII.6 The market demand an supply functions (in Panel A) are initially DM and SM.

Given thess demand and supply functions, the market equilibrium is at point EM resulting in an

equilibrium price (PEM) and quantity (QEM). When the market price is PEM, the firm reacts to

that price (The firm is a price taker.). If the firm’s objective is to maximize profits, it will

operate at the point where MR = MC. This equality of MR and MC occurs at point at Point B in

panel B. Note that the short run MC will lie to the right of the LRMC at this point, so short run

output would be greater. The firm will select plant size SRAC2 since it will minimize the cost

per unit at that output level (QB). This SRAC2 is not the most efficient size plant (SRAC*). The

AR is greater than the AC at this point. The firm can earn “economic profits” under these

conditions. Remember “normal profits” are included in the cost functions.

Since entry is relatively free, other entrepreneurs will desire to capture some of these economic

profits and enter the industry. The supply function will increase (shift to the right) causing the

equilibrium price to fall from PEM to P*. The equilibrium quantity in the market rises but there

are more firms. The firm represented in Panel B must adjust to the lower market price, P*.The

new demand and revenue functions faced by the firm is D*, AR* and MR*.MR* = MC at point

C. The firm reduces output to QC and adjusts plant size to SRAC*.

The firm now is operating where:

the plant that has allows the lowest cost per unit (most efficient size plant),

they operate that plant at the level of output that has the lowest cost per unit,

they earn a normal profit,

They are maximizing their profits given circumstances (They have no incentive to

change output or plant size, they are in equilibrium.),

The price is equal to the MC (This is the condition to optimize the welfare of the

individuals in society given the income distribution.)

250

12.2.2 Profits in Long Run Pure Competition

The process of long run equilibrium in pure competition can be shown in

Figure VII.6. You may remember part of Figure VII.6 as Figure VII.3. Both the

market and an individual firm’s demand and cost (supply) functions are

shown.

In Figure VII.6, it is apparent that a market price below P* would result in

the firm’s AC exceeding the AR at all levels. If this were the case firms would

earn less than normal profits and would have an incentive to leave the market.

As firms leave the market, the market supply decreases (shifts to the left) and

the market price would rise.

There are two important features in pure competition. First each firm is a

price taker and has no market power. The demand function faced by the firm

is perfectly elastic at the equilibrium price established in the market. This is

because the output of the purely competitive firms is homogeneous and there

are a large number of sellers, none of whom can influence the market price.

Secondly, entry and exit from the market is relatively free. Above normal

profits attract new producer/seller that increases the market supply driving the

market price down. If profits are below normal, firms exit the market. This

reduces the market supply and drives the price up.

Long run equilibrium in a purely competitive market is established when

the D (AR and MR) is just tangent to the long run average cost function

(LRAC). This will be at the minimum of the LRAC where its slope is 0 (the

demand function faced by the firm has a slope of 0). Firm earn normal profits

at this point and there is no incentive to enter or leave the market. There is no

incentive to alter plant size or change the output level.

At the point of long run equilibrium in Figure VII.6 at point C, the following

conditions will exist:

251

12.2.2 Profits in Long Run Pure Competition

AR = AC: Firms earn a normal profit. There is no incentive for firms to enter or

leave the market.

LRMC = LRAC: the firm is operating with the plant size that results in the

lowest cost per unit, i.e. the fewest resources per unit of output are used.

MR =LRMC: the firm has no incentive to alter output or plant size.

P = MR =MC: the price reflects the marginal value of the good to the buyers and

the marginal cost to the producer/seller.

Long run equilibrium in pure competition results in an optimal allocation of

resources. The price reflects the marginal benefits of the buyers and the

marginal cost of production. The user of the last unit of the good places a

value (the price they are willing and able to pay) on the good equal to the cost

of producing that unit of the good. Units of the good between 0 and the

equilibrium quantity have a greater value than the cost of production.

The purely competitive model provides a benchmark or criteria to evaluate

the performance of a market: MB = P = MC. The marginal benefit (MB) to the

buyer is suggested by the price they are willing and able to pay. The MB to the

seller is the marginal revenue (MR) they earn. The marginal cost (MC) reflects

the opportunity cost to society.

252

13 Firms With “Market Power”

13 FIRMS WITH “MARKET POWER”

P ure competition results in an optimal allocation or resources given the

objective of an economic system to allocate resources to their highest valued

uses or to allocate relative scarce resource to maximize the satisfaction of

(unlimited) wants in a cultural context. Pure competition is the ideal that is be

benchmark to evaluate the performance markets. The economic theory of

monopolistic competitive markets, oligopoly and monopoly is used to suggest

the nature of problems that may exist when firms or agents have market

power and are able to distort prices away from the purely competitive

optimum.

The existence of market power is tied to the demand conditions the firm

faces. If their product is (or can be differentiated), consumers may have a

preference for one firm’s output relative to others. A negatively sloped

demand function (less than perfectly elastic) allows the firm to raise its price

and not have its sales fall to zero. In pure competition, the firms may all try to

influence market demand (eat Colorado Beef, Eat Black Angus Beef, Drink

Florida orange juice, etc) but individual producers do not advertise their own

product (Eat Rancher Jones’s Beef). Many agricultural markets are close to

pure competition. In many cases some producers try to differentiate their

products. Organic produce is one example.

In pure competition, the firms’ outputs are homogeneous. If the firm has is

no opportunity to differentiate their product they have no incentive to

advertise and to try to influence the demand for their product. If a product can

be differentiated by altering the characteristics of the good or simply by

convincing the consumers that the product is different, the firm achieves

market power. Market power is the ability to have some control over the price

253

13 Firms With “Market Power”

of the good offered for sale. Advertising can be used to differentiate a product

or increase the demand for a product. The crucial factor is the demand for the

firm’s output must be negatively sloped: the firm becomes a “price maker.”

The extent to which a firm is a price maker (i.e. has market power) is partially

determined by the price elasticity of demand in the relevant price range. Note

that when the seller selects a price (price maker) the demand function

determines the quantity that will be purchased.

The conditions of entry or barriers to entry (BTE) are also important

determinants of market power. If there are significant BTE, a firm or firms

may be able to sustain above normal profits over time because other firms are

prevented from entry to capture the above normal profits.

Monopoly is the market structure that is usually associated with the

greatest market power. The monopolist produces a good with no close

substitutes (increased probability the demand is relatively inelastic) and there

are barriers to entry. Firms in monopolistic competition or imperfectly

competitive markets are more likely to have limited market power because

there are many firms with differentiated products (there are substitutes) and

there is relative ease of entry and exit into the market.

254

13.1 Monopoly

13.1 MONOPOLY

A monopoly is a market characterized by a single seller of a good with no

close substitutes and barriers to entry. Monopolies rarely occur in a pure form.

There are almost always substitutes or methods of possible entry into a

market. When the term “monopoly” is used it is usually referring to a degree

of monopoly or market power. In many cases the existence of a monopoly

results in regulation or the enforcement of antitrust laws that attempt to

introduce competition to reduce market power.

The definition of monopoly requires a judgment about the phrase “no close

substitutes” and what “barriers to entry” mean. I might be the only producer

of mink lined, titanium trash cans. This is not relevant as a monopoly since

there are many good substitutes: plastic or steel containers or even brown

paper bags will serve as trash containers. There are substitutes for the

electricity (KWH) produced by a public utility. It is possible to purchase a

portable generator powered by an internal combustion engine or use candles

for use in your home. However, neither of these can be regarded as a close

substitute. The concept of cross elasticity of demand can be used to identify

whether two goods are substitutes on not.

Q

( Cross price elasticity of demand ) E

X

XY

PY

[ a change in the quantity of good X, caused by a change in the price of good Y ]

Barriers to entry are another important characteristic of monopoly.

Complete barriers to entry (BTE) make it impossible for competing firms to

inter a market. However, in n most cases, BTE are not complete but are

relative. Firms’ entry into a market can be restricted by a variety of factors.

BTE’s can be due to:

255

13.1 Monopoly

The ownership of a key resource or location maybe important. ALCOA’s monopoly in

aluminum was at first due to a patent on a low cost process to reduce bauxite into

aluminum. After the patent expired, their ownership of bauxite reserves allowed them

to maintain their monopoly position. In earlier times there may have been only one

location on a river where a dam could be built to power a gristmill. A movie theatre

gains monopoly power over its sale of popcorn by prohibiting customers from bringing

their own food into the theatre.

Information or knowledge not available to others. (Industrial secrets). Knowledge

about a process may kept secret (rather than using a patent since patent information is

publicly available).

Legal barriers such as license, franchise, patent, copyright, etc. ALCOA’s monopoly

began when the government gave them a patent on a low cost method of reducing

bauxite to aluminum. Other methods of making aluminum are possible but cannot

compete with the method pioneered and patented by ALCOA. A State park might

license a firm to provide prepared foods within the boundary of the park. This would

confer market power on the firm unless their price was regulated. A city that licenses a

taxi company gives them market power. They may license several taxi companies so

that there is some competition and or they may regulate the services and rates. Public

utilities often have a license to operate in a specific area. In return for this monopoly

power, they are subject to regulation. In fact, the British colonies that became the

United States and Canada were the result or grants from the British government.

Hudson Bay Company and the East India Companies were firms that were granted

rights to operate in specific areas.

Natural monopoly caused by economies of scale usually associated with a cost

structure with a high fixed cost relative to variable costs. A natural monopoly is the

result of significant economies of scale due to a high fixed cost. As the output

increases the LRAC falls. If the market demand intersects the LRAC as it falls (or at its

minimum), a natural monopoly exists.

256

13.1.1 Profit Maximization In a Monopoly

C, TR )T($

RM

TC

TRM

MT

TCM

CM

TR

QMQT

Q/ut

Figure VIII.1

13.1.1 PROFIT MAXIMIZATION IN A MONOPOLY

S ince a monopoly is characterized by a single seller, the market demand

and the demand faced by the firm are the same. The demand will tend to be

negatively Figure VIII.1 represents profit maximization by a firm in a

monopoly market.

The TR function increases up to an output level of QT then it declines.

Remember that any negatively sloped demand function is elastic at high prices

(top half of demand where price increases reduce TR) and inelastic at low

prices (bottom half of demand where price increases increase TR). The TC

increases at a decreasing rate, passes an inflection point and then increases at

257

13.1.1 Profit Maximization In a Monopoly

an increasing rate. Maximum profits is occurs at the output level where TR

>TR by the greatest vertical distance. This occurs at output QM. Profits are

reflected by the vertical distance, CMRM, or TRM-TCM. At point CM the slope of

the TC (MC) is the same as the slope of the TR at point RM (MR). The

maximum TR occurs at point MT at output level QT. If the firm increases output

from QM to QT profits will decrease because the costs of the additional units

(QT-QM) is greater than the additional revenue produced by those units of

output.

Unit cost and revenue functions can also be used to show the output and

price decisions of a monopolist. In Figure VIII.2 the demand, AR, MR, MC and

AC cost functions are shown.

In Figure VIII.2, revenue and cost functions

MC

for a monopolist are shown. The demand

rice

and AR are negatively sloped, so the MR

P

falls at twice the rate and intersects the Q-

axis half way between the origin and AR

(or demand) intercept.

AC

The firm will maximize profits where MC =

P

H

H

MR (at point Z) producing QH output.

Buyers are willing and able to pay a price of

P

th

H for the QH unit produced (they would

J

be willing to pay more for units from 0 to

CJ

C

F

Q

F

H, but don’t if there is no price

C

C

C

discrimination

Z

The cost per unit is CF, so profits are area

CFFHPH or (PH-CF)QH. Profits are above

AR

normal but BTE prevent others from

entering the market to capture the above

MR

D

normal profits.

0

QH QC

QJ

Q/ut

Figure VIII.2

Figure VIII.2 represents a monopolist. In the long run the monopolist

might adjust the scale of plant, but BTE prevents other firms from entering

and driving profits to normal. Monopoly or market power is suggested by two

258

13.1.1 Profit Maximization In a Monopoly

things. First, the price is greater than the marginal cost (P>MC). Secondly,

above normal profits will persist over time.

13.1.2 IMPERFECT COMPETITION AND MONOPOLISTIC COMPETITION

D uring 1933 Edward H. Chamberlin [1899-1967] and Joan Robinson

[1903-1983] independently published similar theories on “monopolistic” and

“imperfect” competition. The terms “monopolistic competition” and “imperfect

competition” originally were basically the same even though there were subtle

differences. Currently, the use of “imperfect competition” is more generic, it

refers to all market structures that lie between pure competition and

monopoly. In this usage monopolistically competitive and oligopolistic markets

are considered imperfect.

Monopolistically competitive markets are characterized by:

a large number of sellers, no one of which can influence the market,

differentiated products,

relative free entry and exit from the market.

Relaxing the characteristic of outputs from homogeneous to “differentiated

products” was the basic change from the purely competitive market model.

The differentiation of output results in the demand faced by each seller being

less than perfectly elastic. Since there are “many sellers,” many substitutes for

each seller’s output is implied. This suggests that the demand faced by a firm

in a monopolistically competitive market is likely more elastic than in a

monopoly. The elasticity obviously depends on the preferences and behavior

of the buyers. The negative slope of a firm’s demand function in imperfect

competition results in a different result than in pure competition.

259

13.1.2 Imperfect Competition and Monopolistic Competition

The conditions of entry and exit to and from a monopolistically competitive

market are similar to the purely competiti