INTRODUCTION TO
ECONOMICS
Case, Fair and Oster – Principles of Economics
Chapter 12
PINAR DENİZ
pinar.deniz@marmara.edu.tr
GENERAL EQUILIBRIUM AND THE
EFFICIENCY OF PERFECT COMPETITION
• partial equilibrium analysis The process of examining the
equilibrium conditions in individual markets and for households and
firms separately.
• general equilibrium The condition that exists when all markets in an
economy are in simultaneous equilibrium.
• efficiency The condition in which the economy is producing what
people want at least possible cost.
EXAMPLE:
MARKET ADJUSTMENT
TO CHANGES IN DEMAND
Assume that there are two sectors in
the economy, X and Y, and that both
are currently in
long-run equilibrium.
Now assume that a change in
consumer preferences shifts the
demand for X out to the right.
SR?
LR?
• Pareto efficiency or Pareto optimality A condition in which no change is possible that
will make some members of society better off without making some other members of
society worse off.
THE EFFICIENCY OF PERFECT COMPETITION
The three basic questions discussed previously included:
1. What gets produced? What determines the final mix of output?
2. How is it produced? How do capital, labor, and land get divided up among
firms? In other words, what is the allocation of resources among producers?
3. Who gets what is produced? What determines which households get how
much? What is the distribution of output among consuming households?
Efficient Allocation of Resources
among Firms
• The assumptions that factor markets are competitive and open, that
all firms pay the same prices for inputs, and that all firms maximize
profits lead to the conclusion that the allocation of resources among
firms is efficient.
Efficient Distribution of Outputs
among Households
• We all know that people have different tastes and preferences, and
that they will buy very different things in very different combinations.
• As long as everyone shops freely in the same markets, no
redistribution of final outputs among people will make them better
off.
• If you and I buy in the same markets and pay the same prices, and I
buy what I want and you buy what you want, we cannot possibly end
up with the wrong combination of things.
• Free and open markets are essential to this result.
Producing What People Want: The
Efficient Mix of Output
• The condition that ensures that the right things are produced is P =
MC.
• Society will produce the efficient mix of output if all firms equate
price and marginal cost.
PERFECT COMPETITION VERSUS
REAL MARKETS
• We have built a model of a perfectly competitive market system that
produces an efficient allocation of resources, an efficient mix of
output, and an efficient distribution of output. The perfectly
competitive model is built on a set of assumptions, all of which must
hold for our conclusions to be fully valid.
• These assumptions do not always hold in real-world markets.
THE SOURCES OF MARKET FAILURE
• market failure Occurs when resources are misallocated, or allocated
inefficiently. The result is waste or lost value.
• There are four important sources of market failure:
(1) imperfect market structure, or noncompetitive behavior,
(2) the existence of public goods,
(3) the presence of external costs and benefits, and
(4) imperfect information.
IMPERFECT MARKETS
• imperfect condition An industry in which single firms have some control
over price and competition. Imperfectly competitive industries give rise to
an inefficient allocation of resources.
• monopoly An industry composed of only one firm that produces a product
for which there are no close substitutes and in which significant barriers
exist to prevent new firms from entering the industry.
• In all imperfectly competitive industries, output is lower—the product is
underproduced—and price is higher than it would be under perfect
competition.
• The equilibrium condition P = MC does not hold, and the system does not produce
the most efficient product mix.
PUBLIC GOODS
• public goods, or social goods Goods or services that bestow
collective benefits on members of society. Generally, no one can be
excluded from enjoying their benefits. The classic example is national
defense.
• private goods Products produced by firms for sale to individual
households.
EXTERNALITIES
• externality A cost or benefit resulting from some activity or
transaction that is imposed or bestowed on parties outside the
activity or transaction.
• The market does not always force consideration of all the costs and
benefits of decisions. Yet for an economy to achieve an efficient
allocation of resources, all costs and benefits must be weighed.
IMPERFECT INFORMATION
• imperfect information The absence of full knowledge concerning
product characteristics, available prices, and so forth.
• The conclusion that markets work efficiently rests heavily on the
assumption that consumers and producers have full knowledge of
product characteristics, available prices, and so forth.
• The absence of full information can lead to transactions that are ultimately
disadvantageous.
EVALUATING THE MARKET
MECHANISM
• Freely functioning markets in the real world do not always produce an
efficient allocation of resources, and this result provides a potential
role for government in the economy!
