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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 Economic
Mbarohey Reply
Economic is a social science that study human behavior in relationship with end and scarce means which have alternative uses
Agyenkwa
Economics is an inquiry into nature that causes wealth of nations.
Eric
what are the importance of economic
Mbarohey
it helps us use our limited resources to satisfy our unlimited wants
Daniel
economic is the science of wealth
Joseph
it's helps us to be current on what's going on in the world
Joseph
economics can be defined as the science of wealth
Joseph
what are the advantages of sole proprietorship
Mbarohey
is the study of mankind in the ordinary business
Awini
What is the formula for calculating elasticity?
Haruna Reply
government spending increase will cause economic grew
Jia Reply
no
Helicia
what is trade by batter
Iko Reply
trade involves the transfer of good or services from one person to another, often in exchange for money.
musadique
Now trade by batter :it may define as form of trading in which good are exchange directly for other goods without the use of money as medium of exchange
musadique
is it good to trade with something with a value but given something which has no value
sandra
trade in batter means the exchange of goods and services without using money
Maa
It may be defined as an exchange of goods to satisfy the needs of two parties
Haruna
mention six factors that explain efficiency and productivity of labour
fanelchainz Reply
mention six factors that explain efficiency and productivity of labour
bohvy
factors that explain efficiency of labor are 1.population, 2.technology, 3.education, 4.working environment, 5.incentives (tax holidays) and 6.religious or cultural beliefs.
Solomon
What is demand
SoFIA Reply
is the abulity and willingness of a consumer to purchase goods and services at a particular peeiod of time in a given price
Fadhil
what is a central bank
Fadhil Reply
transactionsss with all banks of any country
Economics
what is elastic
fadoju Reply
changee
Economics
variation
Economics
how is equilibrium defined in financial market?
infinity Reply
what is the definition of money
infinity
Money is define as anything that is generally acceptable as a means of exchange nd settlement of dept
Simeon
what is elastic
fadoju
what is demand and supply
Osman
demand is ability of a consumer to purchase a particular good at a particular time
Maa
supply is the ability of a person to be able to provide his costumers with what they need
Maa
how do choices end up determining what, how and for whom goods and services are produced
Ayesha Reply
They end up by using the scale of preference
Maa
there are 10 000 seats available for the Wimbledon tennis Championships. the price per ticket is fixed by the organisers. the supply of seats is thus: A. completely elastic B. completely inelastic C. elastic D. unitary elastic E. elastic which option is the answer?
Esihle Reply
unitary
Economics
unitary elastic
Rema
unitary
Joseph
unitary elastic
Anyere
unitary elastic
Anyere
completely inelastic
Solomon
what is international trade
Naomi Reply
the trade between two or more countries outside the territory of own country
Mukeem
it's an international trade
Ivan
Multilateral trade it is
Antony
It is the exchange of goods and services among two or more countries.
Gideon
Oh yes
Adu
is the buying and selling of Good's and services outside the country
Helicia
what is consumer choice as the result of maximization choice ?
musadique
what is the difference between public corporation and public limited liability
Frank
how do monopolistic firm make profit in the short run and long run
Ediga Reply
oligopolistic competition is known to have a kinked demand curve .why there is such a tease my in oligopolistic form only
Ediga
please can anyone help me in econs
Oppong
Manuel in which context
Daizy
please in utility
Oppong
what is demand ?
Tonight Reply
The amount of some goods or services consumers need to purchase
Adu
The amount of goods or services that consumers are willing and can afford to purchase.
Ivan
it is goods and services consumers are willing and able to buy at given price over a given period of time
Rebecca
as quantity of good and service that a consumer is willing and able to purchase at a given price and at the particular market price.
MOHAMMED
The amount of goods and services consumers are able and willing to buy and pay for at a given price and at given point in time.
Solomon
refers to the quantity of goods and services that customers are willing and able to purchase at various prices over a period of time
Ryt
Demand may define as goods and services which a consumer is willing to buy at a given price over a perticular market price
Osman
what are subsidies
Yaya Reply
how do trade unions deal with subsidies
Yaya
bro can you explain decision making
WhatsApp
Decision making is a process to use your limited resources for best productive purpose.
Dipam
explain why an increase in national income may not always lead to improvement in economic wellbeing of all the citizens?
Mendo
How many types of labour do we have pls
ROA
two
nabil
skilled and unskilled labour
nabil
Thanks 🙏
ROA
what are the factors that affects efficiency of labour ?
nabil
What are tools of economics analysis
Adu
Adu Tumwah,,, The tools of economics analysis are; Charts, graphs, equations, table, arithemetic mean, etc.
Dennis
Subsidies are payments made by the government to the producers of goods and services
Daizy

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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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