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Short-run outcomes for perfectly competitive firms

The average cost and average variable cost curves divide the marginal cost curve into three segments, as shown in [link] . At the market price, which the perfectly competitive firm accepts as given, the profit-maximizing firm chooses the output level where price or marginal revenue, which are the same thing for a perfectly competitive firm, is equal to marginal cost: P = MR = MC.

Profit, loss, shutdown

The graph shows how the marginal cost curve reveals three different zones: above the zero-profit point, between the zero profit point and the shutdown point, and below the shutdown point.
The marginal cost curve can be divided into three zones, based on where it is crossed by the average cost and average variable cost curves. The point where MC crosses AC is called the zero-profit point. If the firm is operating at a level of output where the market price is at a level higher than the zero-profit point, then price will be greater than average cost and the firm is earning profits. If the price is exactly at the zero-profit point, then the firm is making zero profits. If price falls in the zone between the shutdown point and the zero-profit point, then the firm is making losses but will continue to operate in the short run, since it is covering its variable costs. However, if price falls below the price at the shutdown point, then the firm will shut down immediately, since it is not even covering its variable costs.

First consider the upper zone, where prices are above the level where marginal cost (MC) crosses average cost (AC) at the zero profit point. At any price above that level, the firm will earn profits in the short run. If the price falls exactly on the zero profit point where the MC and AC curves cross, then the firm earns zero profits. If a price falls into the zone between the zero profit point, where MC crosses AC, and the shutdown point, where MC crosses AVC, the firm will be making losses in the short run—but since the firm is more than covering its variable costs, the losses are smaller than if the firm shut down immediately. Finally, consider a price at or below the shutdown point where MC crosses AVC. At any price like this one, the firm will shut down immediately, because it cannot even cover its variable costs.

Marginal cost and the firm’s supply curve

For a perfectly competitive firm, the marginal cost curve is identical to the firm’s supply curve starting from the minimum point on the average variable cost curve. To understand why this perhaps surprising insight holds true, first think about what the supply curve means. A firm checks the market price and then looks at its supply curve to decide what quantity to produce. Now, think about what it means to say that a firm will maximize its profits by producing at the quantity where P = MC. This rule means that the firm checks the market price, and then looks at its marginal cost to determine the quantity to produce—and makes sure that the price is greater than the minimum average variable cost. In other words, the marginal cost curve above the minimum point on the average variable cost curve becomes the firm’s supply curve.

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Questions & Answers

what is deadweightloss
francis Reply
hi
Bless
deadweight loss is the allocative inefficiency.... when the equilibrium for good or services is not achived.
Azhar
hi
Azhar
hi
azaloo
hii too
Jackson
Hello
Micah
how are you all?
Azhar
I am here been sick but here
Amanda
may you get well soon Amanda
Azhar
What are the implications of classical Economics?
Micah
What are the implications of classical Economics school of thought?
Micah
Dead weight loss is an inefficient allocation of resources, especially through taxation or restrictions.
Ezeigwe
Classical Economics had an influenced by ancient economic principle and theory.
Ezeigwe
hello please what is localization of industry
Bless Reply
price is tantalisingly the only factor determining demand which can be analyze the view
Sinit Reply
Price is tantalizingly the only factor determining demand which can be analyze the view
Sinit
what is scarcity
Sharkdanny Reply
the state of being scarce or in short supply; shortage.
Abdirahin
what is meant by an abnormal demand curve?
Samuel Reply
what is microeconomics
Berun Reply
micronomics can be define as that part of Economics that deals with small scale business. e.g. House hold stuff
Amodu
Micro economics is the study of individuals, households and firms' behavior un decision making and allocation of resources
Christian
what is underemployment
Xornam Reply
It is the situation where the available resources are not used to it optimum
Bless
state the law of diminishing returns
Bless
Bless, the law of diminishing returns state that one point, adding a single worker will result in a decrease of production.
David
it is a situation where by people are employ but work under their potential
Akua
David please go into details kk
Bless
Akua pls when you say people alone? what about facilities?
Bless
Definition of underemployment. 1 : the condition in which people in a labor force are employed at less than full-time or regular jobs or at jobs inadequate with respect to their training or economic needs
Boahen
OK that is good
Set
I am new here
Taimoor
what does law of demand says?
Samuel
with a diagram explain fairy elastic demand
Samuel
comprehensive answer for public finance is the money that a government has available to spend from taxes and borrowing.
wilflay Reply
what then comprises of public opinion
Raphael
what is macro economics
SAGAR Reply
Definition of demand and supply
oyebanji Reply
whatd is name of economic scholars defined classic view
Ahmed Reply
Whole Classical view is based on J.B.Say's Law of Marker demand
abhinav
the science of economic has both positive and normative aspect,discuss.
Mkiwa Reply
simplified definition of a production possibility curve
Rose Reply
This is call the PFF curve .
Sumowoui
A country can produce lots of guns, or lots of butter. But, they cannot produce lots of both. The solution to this is called comparative advantage. Comparative advantage is that different countrys specialize in different areas, and then trade.
David
this is call the. pff curve
Murali
It is defind as a curve which shows various combinations of two goods produced with given resources
Shahid
it means a country with a given level of technology and available resources can produce two goods only if the technology or resources are efficiently utilize. In d process of utilization you will produce one goods more than the other that is why the downward slope of a PPC curve indicates opp cost
Odion
Shows all the possible combination of two goods or services
Christian
it is d intersection of two different variables
Odion Reply
what is equilibrium ?
James Reply
the quantity of demanded for a good is equal to its quantity supplied. Qdd=Qss
Podol
in economics, an equilibrium is situation in which : 1. qd=qd 2.no tendency or quantity to change 3. the market just clears without surplus/shortage
Podol
it is the intersection between two variables. Because you did not specify the equilibrium you talking about is it consumer or market forces
Odion
A state in which opposing forces or influences are balanced
Preeti
Equilibrium refers to the economic situation where supply and demand for a certain goods and services in market is equal, which represents a stable market price to purchase and sell.
Preeti
curve d and s intersection
Podol
yes jahan par demand and supply intersect karte hai wahi par equilibrium hota hai
Preeti
Equilibrium is when two variables intersect.
Akolo
equilibrium is a point where demand and supply meet with out shortages or surplus.
Sumowoui
Hmm scholars
Odion
am new here I want to know more about economics
Mansur
Micro and macro
Mansur
What do you think?
Yussif
can someone explain demand and supply
Mansur
demand is a quantity of a commodity which could be offer for sales at a particular price. !!!!...And supply is also a quantity of a commodity which could be brought by a consumer at a given price and time.
Rosemary
m also new want to know more about economics
Gift
kk
Rosemary
txup rose
Gift
hi
Rosemary
u gud
Gift
yes nd u? by d way who are u!!
Rosemary
m gift wer u from?
Gift
Ibadan
Rosemary
nd u
Rosemary
wer s the place o wic country?
Gift
Nigeria
Rosemary
lusaka
Gift
ooooh
Rosemary
wats yo username?
Gift
RaviKumar
Ravi

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Source:  OpenStax, Principles of economics. OpenStax CNX. Sep 19, 2014 Download for free at http://legacy.cnx.org/content/col11613/1.11
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