Chapter 10 monopoly
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Chapter 10 Monopoly. 3 Properties of Monopoly 1) One Seller 2) No Close Substitutes 3) Extremely High Barriers to Entry. What are the barriers to entry? 1) Government Restrictions – Patents 2) Economies of Scale – Natural Monopoly 3) Restricted Ownership of Raw Material - ALCOA.

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Chapter 10 Monopoly

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Chapter 10 monopoly

Chapter 10Monopoly


3 properties of monopoly 1 one seller 2 no close substitutes 3 extremely high barriers to entry

3 Properties of Monopoly1) One Seller2) No Close Substitutes3) Extremely High Barriers to Entry


Chapter 10 monopoly

What are the barriers to entry?1) Government Restrictions – Patents2) Economies of Scale – Natural Monopoly3) Restricted Ownership of Raw Material - ALCOA


Chapter 10 monopoly

Monopoly and MicrosoftComputers in the early 1980’s1) Apple II2) Commodore PC3) Atari 400 (48k)4) TRS-805) IBM PC


All had incompatible operating systems

All had incompatible operating systems


Next generation mid 1980 s 1 early macs 2 commodore amiga 3 atari st 4 5 ibm 386 s 486 s

Next Generation – Mid 1980’s1) Early Macs2) Commodore Amiga3) Atari ST4) ---5) IBM 386’s, 486’s


The amiga and atari st are dying of software suffocation

The Amiga and Atari ST are dying of software suffocation.


Chapter 10 monopoly

By the late 1990’s, only the IBM and its clones, and the Mac are left.IBM doesn’t have near monopoly because of the clones, but Microsoft does for Windows


Microsoft starts to use this monopoly of windows to take over word processing and web browsing

Microsoft starts to use this monopoly of Windows to take over word processing and web browsing


Government antitrust suit against microsoft 1999

Government Antitrust Suit Against Microsoft (1999)


Chapter 10 monopoly

Bush wins the election of 2000 and the Republican lawyers drop the case in return for Microsoft’s promise not to do it again.


Chapter 10 monopoly

This is a variation of the economies of scale. How can you make a computer/operating system to compete with Microsoft when the software industry is designed to work with Windows? You would have to provide your own software, which would mean starting on a huge scale.


Chapter 10 monopoly

If this is the market demand curve for the monopoly’s product, what is the monopoly firm’s demand curve?

Market

Firm

P

P

P1

?

P2

D

Q1

Q

Q2

Q


The firm s demand curve is the same as the market s because the firm is the market

The firm’s demand curve is the same as the market’s because the firm is the market.

Market

Firm

P

P

=

P1

P1

P2

P2

D

Q1

Q1

Q

Q2

Q2

Q


Chapter 10 monopoly

What’s the relationship between price and marginal revenue for amonopoly? Q P TR MR 0 $10 $0 -- 1 $8 $8 $8 2 $6 $12 $4 3 $4 $12 $0 4 $2 $8 -$4 5 $0 $0 -$8


Chapter 10 monopoly

What’s the relationship between price and marginal revenue for amonopoly? Q P TR MR 0 $10 $0 -- Marginal revenue is 1 $8 $8 $8 below price because 2 $6 $12 $4 each additional unit 3 $4 $12 $0 you sell causes the 4 $2 $8 -$4 price of the other 5 $0 $0 -$8 units to drop also.


Chapter 10 monopoly

Suppose McDonalds is currently selling 100 hamburgers at 50 cents each. TR = $50They lower their price to 40 cents and now sell 150. Will their total revenue rise by 50 hamburgers times 40 cents = $20?


Chapter 10 monopoly

No. Total revenue rises by 50 hamburgers times 40 cents minus 100 hamburgers times 10 cents = $10. Let’s double-check. Q x P = TR100 hamburgers x 50 cents = $50150 hamburgers x 40 cents = $60Yep, it checks.


How to graph the demand and marginal revenue curve for a monopoly

How to graph the demand and marginal revenue curve for a monopoly.

P

For straight lines, the MR curve hits the horizontal axis halfway between where the demand curve does and the origin.

D

MR

0

Q

0


Chapter 10 monopoly

So how much will the monopolist produce, and what price will he charge? Q P TR TCπ MR MC 0 $10 $0 $0 -$10 --- --- 1 $8 $8 $3 $5 $8 $3 2 $6 $12 $6 $6 $4 $3 3 $4 $12 $9 $3 $0 $3 4 $2 $8 $12 -$4 -$4 $3 5 $0 $0 $15 -$15 -$8 $3


The marginal decision rule again produce the quantity where mr mc

The Marginal Decision Rule AgainProduce the Quantity Where MR=MC

Then up to the demand curve to determine the price.


Profit or loss same rule as before p atc profit p atc loss

Profit or Loss? Same rule as before.P>ATC ProfitP<ATC Loss


Price and quantity of donuts in a market with perfect competition

Price and quantity of donuts in a market with perfect competition.

P

Perfect Competition

P=ATC

MC=ATC

Pc=0.4

D

0

Q

0

Qc=600


Price and quantity of donuts in a monopoly

Price and quantity of donuts in a monopoly.

P

m for monopoly

c for competitive

Monopoly

MR=MC

Pm=0.7

MC=ATC

Pc=0.4

D

MR

0

Q

0

Qc=600

Qm=300


Chapter 10 monopoly

With perfect competition, the price of donuts is 40 cents and 600 are made.With monopoly, the price of the donuts is 70 cents and 300 are made.The monopolist makes less of the product to create a scarcity and raise the price up.


Price discrimination is charging different prices to different customers

Price discrimination is charging different prices to different customers.


You would like to charge a higher price to the customers at the higher end of the demand curve

You would like to charge a higher price to the customers at the higher end of the demand curve.

P

D

0

Q

0


Who are these people sometimes they are richer people what traits are associated with being poor

Who are these people? Sometimes they are richer people. What traits are associated with being poor?


Chapter 10 monopoly

What traits are associated with being poor?Traditionally, retired seniors have been poor, and students.


Chapter 10 monopoly

It costs $6 to make dinners at your restaurant. When you charge $12, you get one customer, when you charge $10, you get two. Would you rather charge $12 or $10?Can you do better with price discrimination?What if you have noticed the additional customers when it is cheaper are mostly seniors?


Chapter 10 monopoly

Charge straight $12Profit = $12 - $6 = $6Charge straight $10Profit = $20 - $12 = $8Charge one customer $12 and the other (senior) $10.Profit = $22 - $12 = $10


Chapter 10 monopoly

This could also explain student discounts at the movie theater.What else could distinguish people from the high price end of the demand curve and the lower end?


Think about men and women if this was demand for baseball tickets

Think about men and women if this was demand for baseball tickets.

P

And what if it was demand at the hair salon?

D

0

Q

0


Chapter 10 monopoly

There’s a reason the Washington Nationals have ladies night and not mens night. There’s a reason California hair salons were sued for charging women higher prices.


Chapter 10 monopoly

What about quantity discounts? There’s a reason bakers give a free donut if you buy a dozen. Donuts price = $1. Cost of making donuts = 50 cents.Sell 8 and charge for them all.Profit = $8 - $4 = $4Sell 13 and charge for 12.Profit = $12 - $6.50 = $5.50


Chapter 10 monopoly

NEW YORK NYC Human Rights Commission Drops Charges Against Chinese RestaurantBy Meg Marco May 2, 2007 The case of the Wisconsin man who filed a complaint with the NYC Human Rights Commission has come to a close with the commission dropping charges against the restaurant.


Chapter 10 monopoly

… “We saw other customers getting a different menu. We were told we could order from it if we spoke Chinese.” The Chinese menu had prices that were, on average, $1 cheaper per dish.


Chapter 10 monopoly

Soon after the dust-up, Mayor Bloomberg urged a boycott of the shady Chinese restaurant. “It’s unconscionable to use race on any of these things, in terms of what kind of service, or how you charge, or whatever,” Bloomberg told the Daily News.


Chapter 10 monopoly

The Human Rights Commission dropped the charges after the guy from Wisconsin settled with the restaurant for an undisclosed sum and, “a promise to change its menu – by “listing identical prices in English and Chinese for the same dishes,”


Chapter 11 monopolistic competition and oligopoly

Chapter 11Monopolistic Competition and Oligopoly


Chapter 10 monopoly

Monopolistic Competition1) Many Sellers2) Similar Products or Differentiated Products3) Easy Entry/Exit


Chapter 10 monopoly

Restaurants are the “typical” example of monopolistic competition that we are usually going to use. Other examples are barbers and hair salons, and auto-repair shops.


So what does the demand curve look like for a firm in monopolistic competition

So what does the demand curve look like for a firm in monopolistic competition?

Perfect Competition

P

P

Monopoly

D

D

Q

Q


Chapter 10 monopoly

If McDonalds raises the price of the Big Mac by 10 cents, do they lose all of their customers?Do they have to lower their price to sell more?


Chapter 10 monopoly

So McDonalds demand curve slopes down like a monopoly. It does probably lose more customers with a price increase than a monopoly, so it will be flatter.

Monopolistic Competition

P

P

Monopoly

D

D

Q

Q


Chapter 10 monopoly

You don’t have to worry about drawing it flatter. We’ll assume the units on the axis take card of that.

Monopolistic Competition

P

P

Monopoly

D

D

Q

Q


Chapter 10 monopoly

Since the demand curve slopes down showing that Rosa has to lower the price of all her spaghetti dinners to sell more, her marginal revenue is below price.

Monopolistic Competition

MC

P

D

Q

MR


Now it is simply adding the mc and setting mr mc as before

Now it is simply adding the MC and setting MR=MC as before.

Monopolistic Competition

MC

P

P1

D

Q1

Q

MR


Chapter 10 monopoly

And guess what? The rule about showing a profit and loss is the same too. P> ATC then profit. P<ATC then loss.

MC

P

ATC

P1

D

Q1

Q

MR


Chapter 10 monopoly

What about profits in the long-run?What happens when you have both easy entry and differentiated goods?


Chapter 10 monopoly

Imagine restaurants in Bakersfield are making positive economic profits. What will happen to the number of restaurants?


Chapter 10 monopoly

These new restaurants will keep opening until profits for the typical restaurant are driven to $0. Does this mean all restaurants are making $0 profit like the wheat farms in perfect competition?


Chapter 10 monopoly

Some places, probably only a few, will be able to differentiate themselves enough from the their competitors to keep their profits.


Chapter 10 monopoly

So the result will be that profits usually go to zero in the long-run, but not always.Though even if you have a better restaurant in some way and can make profits even in the long-run, it will be hard to maintain that advantage.


Oligopoly 1 few sellers 2 identical or differentiated products 3 high barriers to entry

Oligopoly1) Few Sellers2) Identical or Differentiated Products3) High Barriers to Entry


Chapter 10 monopoly

Most of the famous brand name competition you know falls in this category: 1) Ford, GM, Chrysler 2) Coca-Cola and Pepsi 3) Nike and Adidas


Chapter 10 monopoly

The high barrier to entry is often that the factories have economies of scale, so there is a high fixed cost to enter.There might also be strong brand loyalty and its associated high advertising cost.


For once we don t have a demand curve and the rule to set mc mr why not

For once we don’t have a demand curve and the rule to set MC=MR.Why not?


Ford currently has price p1 and is selling q1 cars what happens if they have a 20 off sale

Ford currently has price P1 and is selling Q1 cars. What happens if they have a 20% off sale?

D1 – GM doesn’t change price

D2 – GM cuts price 10%

D3 – GM cuts price 20%

P1

P2

?

?

Q1

?


Chapter 10 monopoly

Unless Ford knows how GM is going to respond, they don’t know many additional sales they are going to get with a price cut. The key word for oligopoly is interdependence.


Why haven t we worried about how competitors respond to our price changes before

Why haven’t we worried about how competitors respond to our price changes before?


Chapter 10 monopoly

1) Monopolies don’t have competitors.2) In Perfect Competition, we don’t lower our price. If we did, our competitors would laugh at us and keep charging the equilibrium price.3) What about Monopolistic Competition?


Chapter 10 monopoly

400 restaurants in Bakersfield. Rosa’s Italian Restaurant serves 200 dinners in a typical night. Rosa cuts her price by 20% and gains 20% more customers. BTW, what is her elasticity of demand if this happens?


Chapter 10 monopoly

Rosa’s gets 40 more customers a night. How many customers do most of the 400 other restaurants in Bakersfield lose?So how do they respond?Rosa's Italian Restaurant Open everyday! (661) 872-1606


Chapter 10 monopoly

This is Rosa’s demand curve for her spaghetti dinners. What am I assuming the other restaurants are doing as she lowers her price from P1 to P2?

P

P1

P2

D

0

Q

Q1

Q2

0


Can i make the same assumption between ford and gm so what are we going to do

Can I make the same assumption between Ford and GM?So what are we going to do?


Chapter 10 monopoly

East U.S. Steel and West U.S. Steel are the two competing steel companies in the country. Steel costs $10 a ton to make. Currently they are competingand have a priceof $11 aton.

P

MC

$11

$10

D

0

Q

Qa

0

MR


Chapter 10 monopoly

If they cooperate in setting a price that will make the most money for them jointly, how would you find that price?

P

MC

$11

$10

D

0

Q

Qa

0

MR


Chapter 10 monopoly

Act like a monopoly, reduce output and raise price until MR = MC. Now the price is $13 and they are jointly producing Qm.

P

$13

MC

$11

$10

D

0

Q

Qa

Qm

0

MR


Chapter 10 monopoly

These two firms are price fixing. Price fixing is when firms agree to jointly produce less output and raise the price. A cartel is a group of businesses that are price fixing or in collusion.


Chapter 10 monopoly

This is in many cases illegal. But it is like everything else, it is only illegal if you get caught. You don’t announce it or admit it … unless you get caught.


Chapter 10 monopoly

So, is that it? Big firms will always successfully collude unless the government stops them? No, there is something else, something called the Prisoner’s Dilemma.


Chapter 10 monopoly

Suppose the police pick up 2 men they suspect of bank robbery. They have enough evidence to convict them for illegal possession of a gun, but need a confession to get them for bank robbery.


Chapter 10 monopoly

Prisoner 2

Hold Out

Confess

Hold Out

Pris 1: 20 Years

Pris 2: 0 Years

Pris 1: 1 Year

Pris 2: 1 Year

Prisoner 1

Pris 1: 10 Years

Pris 2: 10 Years

Pris 1: 0 Years

Pris 2: 20 Years

Confess


Chapter 10 monopoly

Cooperation in holding out is the best joint outcome, but it is hard to get their because, given what the other person has done, confessing is always the best choice for each individual to make.


The dark knight film clip

The Dark Knight Film Clip


So what does this all have to do with cartels

So what does this all have to do with cartels?


Chapter 10 monopoly

Firm 2

Keep Agreement

Cheat

Keep

Agreement

Firm 1: $10

Firm 2: $90

Firm 1: $60

Firm 2: $60

Firm 1

Firm 1: $30

Firm 2: $30

Firm 1: $90

Firm 2: $10

Cheat


Chapter 10 monopoly

So we have two forces acting on the firms at the same time.1) The awareness that they make more money if they cooperate than if they both don’t.2) The awareness each has that he makes the most money if he says he will cooperate, but then doesn’t.


Chapter 10 monopoly

So it is not certain in this model what will happen, but that fits real life, where many different outcomes have occurred.


Chapter 10 monopoly

What makes a cartel more likely to work?1) Less Firms2) More Personal Trust3) Easier to Watch the Other Guy4) A Way to Punish the Other Guy5) Stable Demand For the Product6) Repeated Opportunities


Chapter 10 monopoly

Suppose it costs $100 to fly someone from LAX to SFO. The airlines could agree on a price of $200 but would be vulnerable to the prisoner’s dilemma


Chapter 10 monopoly

What if they can get the government to set them a price of $160? Are they safe from the prisoner’s dilemma?


How else do airlines compete besides price

How else do airlines compete besides price?


Chapter 10 monopoly

This quality of service competition raises the cost of flying a passenger up close to $160. So are the airlines making high profits from their guaranteed high price of $160?


Chapter 10 monopoly

The same story explains why banks famously used to give something away when you opened a bank account.


What happened to the free toasters

What happened to the free toasters?


Chapter 12 wages and employment in perfect competition

Chapter 12Wages and Employment in Perfect Competition


What does economics have to say about the wages workers make and how many are hired

What does economics have to say about the wages workers make and how many are hired?


Chapter 10 monopoly

NQ MPPL N=Number Workers3 150 -- Q=Quantity Cookies4 200 50 MPPL=Marginal 5 240 40 Physical 6 270 30 Product of7 290 20 Labor


Chapter 10 monopoly

New Term – Marginal Revenue Product of Labor = Increase in Total Revenue Achieved by Adding One More WorkerNQ MPPL MRPL3 150 -- 4 200 50 5 240 40 6 270 30 7 290 20


Chapter 10 monopoly

If the price of a box of cookies is 3 dollars each, then:NQ MPPL MRPL3 150 -- 4 200 50 $150 5 240 40 $120 6 270 30 $90 7 290 20 $60


Marginal factor cost mfc increase in total cost caused by buying one more input

Marginal Factor Cost = MFC = Increase in total cost caused by buying one more input.


Chapter 10 monopoly

If MFC = $135, how many workers would you hire? What if MFC = $75? NQ MPPL MRPL3 150 -- 4 200 50 $150 5 240 40 $120 6 270 30 $90 7 290 20 $60


So the rule is buy workers up to the point where mrp mfc

So the rule is buy workers up to the point where MRP = MFC.


Graph of mrp for this business

Graph of MRP for this business.

$

$150

$120

$90

$60

MRP

0

Q

0

4 5 6 7


The mrp curve is the demand curve for labor

The MRP curve is the demand curve for labor

$

MFC1

$150

$120

MFC2

$90

$60

MRP

0

Q

0

4 N1 5 6 N2 7


Chapter 10 monopoly

Now that we have the individual firm’s demand curve for labor, we can add all the firm’s individual demand curves to get the market demand for that kind of labor.


Here is the total demand curve now we add in the supply curve

Here is the total demand curve. Now we add in the supply curve.

$

$150

$120

$90

Firm demand curves

$60

DL

0

Q

0

40 50 60 70


Equilibrium wage is 90 and 55 workers are hired

Equilibrium wage is $90 and 55 workers are hired.

$

SL

$150

$120

$90

$60

DL

0

Q

0

40 50 60 70


What if technological progress increases mrp and thus demand

What if technological progress increases MRP and thus Demand?

$

$150

$120

DL2

$90

$60

DL1

0

Q

0

40 50 60 70


Increase in equilibrium wage from 90 to 120 and number of workers hired from 55 to 60

Increase in equilibrium wage from $90 to $120 and number of workers hired from 55 to 60.


Chapter 10 monopoly

The name for the theory of wages we are using here is the Marginal Productivity Theory of Factor Input Prices. It state that under competition, factor inputs are paid the marginal revenue produce.


Chapter 10 monopoly

Imagine a bag of fertilizer that has a MRP of $90. In other words, one bag used on farm land will cause $90 more wheat to grow. What will its price in the farm supply store be? Could it be $60?


Chapter 10 monopoly

At $60, there will be a rush to buy it. Buying it is like buying a box that you can put $60 in one end and $90 comes out the other. This will cause a shortage that will drive up the price. The rush will last till the price reaches $90.


Chapter 10 monopoly

If the price starts at $120, then no one will want to buy it until the price falls to $90. The equilibrium price will adjust to its MRP of $90.


Chapter 10 monopoly

Same for pop singers. Suppose Shakira makes $5 million revenue for her record company. Further suppose they are currently paying her $1 million. Do they like that deal?


Chapter 10 monopoly

Of course they do. But how can the record company across the street see a way to make money for themselves out of this situation whenher contract with theoriginal company expires?


Chapter 10 monopoly

With many firms “bidding” for her services, her price should end up at $5 million. If there was only the one firm, they could stand firm at $1 million.


Chapter 10 monopoly

As for pop singers, so for accountants. If accountants make an MRP of $80,000 for their businesses, their wage should be $80,000. Can you explain why?


Chapter 10 monopoly

Let’s clear up a couple of loose ends. 1) When we say workers are paid their MRP, do we mean they all get the same wage or different wages.2) If a business pays all its workers all they produce, how can they stay in business? Will there be anything left over for profit?


Chapter 10 monopoly

Let’s attach names to our workers. Remember, price = $3.NQ MPPL MRPL3 150 -- Amy4 200 50 $150 Bart5 240 40 $120 Carla6 270 30 $90 David7 290 20 $60


Chapter 10 monopoly

What is the most the company is willing to pay David to show up?NQ MPPL MRPL3 150 -- Amy4 200 50 $150 Bart5 240 40 $120 Carla6 270 30 $90 David7 290 20 $60


Chapter 10 monopoly

If the workers are interchangeable, what is the most they are willing to pay Amy to show up? NQ MPPL MRPL3 150 -- Amy4 200 50 $150 Bart5 240 40 $120 Carla6 270 30 $90 David7 290 20 $60


Chapter 10 monopoly

So long as the workers are interchangeable, all of them end up getting paid $60, not just David. The MRP of a person is not necessarily the same as the MRP of the job they are doing.If Amy is not interchangeable with the others, then she can get $150 while they get $60 each.


Chapter 10 monopoly

What is total revenue to the company from 290 cookies. What is the labor bill?NQ MPPL MRPL3 150 -- Amy4 200 50 $150 Bart5 240 40 $120 Carla6 270 30 $90 David7 290 20 $60


Chapter 10 monopoly

Total Revenue P x Q = $870.Wage Bill = $60 x 7 = $420.This does not guarantee a profit as there are other costs, but there is a chance for one.


Chapter 10 monopoly

What if the market wage is $90 and government raises it to $120?NQ MPPL MRPL3 150 -- Amy4 200 50 $150 Bart5 240 40 $120 Carla6 270 30 $90 David7 290 20 $60


Raising the minimum wage from 90 to 120

Raising the minimum wage from $90 to $120.

$

$150

$120

$90

$60

MRP

0

Q

0

4 5 6 7


Minimum wage of 120

Minimum wage of $120.

$

SL

Surplus Labor

$150

$120

$90

$60

DL

0

Q

0

40 N2 50 N1 60 70


Chapter 10 monopoly

Let’s tell a long-term story of men, women, technology, and MRPIn the old days (say 1014), we know that men and women had different rights and responsibilities. By our standards, it was an unequal society. Why?


What percentage of the jobs depending at least partly on physical strength to do the job well

What percentage of the jobs depending at least partly on physical strength to do the job well?


Almost everyone is poor what is your retirement plan

(Almost) everyone is poor, what is your retirement plan?


Chapter 10 monopoly

Given your retirement plan, and given that half your kids are going to die before adulthood, how many kids do you want to have?


How many jobs depend heavily on physical strength now why

How many jobs depend heavily on physical strength now? Why?


What caused this

What caused this?


Chapter 10 monopoly

In the terminology of this chapter, technology has made the MRP of men and women equal. And this has had great social consequences.


What matters know is what you know not how big a rock you can lift

What matters know is what you know, not how big a rock you can lift.


Chapter 10 monopoly

This same thing has increased the inequality between the educated and the uneducated. Who knows what the future will bring … but I do know one thing.


You want training that will work with the machines and not against them

You want training that will work with the machines and not against them.


Chapter 7 the analysis of consumer choice

Chapter 7The Analysis ofConsumer Choice


Chapter 10 monopoly

So you go to the store and buy a bag of groceries. I stop you outside the store and ask why you bought that combination of goods and not a different combination.


Chapter 10 monopoly

You answer something like, “These are the things I like the best for the money.”Economists call the benefit or satisfaction you get from something its utility.


Chapter 10 monopoly

You make your choices on what to buy or do to get the most utility possible. Utility is an all things considered measure of benefit, not just how pleasurable something is.


1 st donut 2 nd 3 rd 4 th marginal 10 utils 8 utils 3 utils 1 utils utility

1st Donut 2nd 3rd 4thMarginal 10 utils 8 utils 3 utils -1 utilsUtility


Chapter 10 monopoly

1st Donut 2nd 3rd 4thMarginal 10 utils 8 utils 3 utils -1 utilsUtilityTotal 10 utils 18 utils 21 utils 20 utilsUtilityIf the donuts are free, how many donuts would you take?


Chapter 10 monopoly

Law of Diminishing Marginal Utility – As you get more of a good or activity, the increase in total utility decreases with each additional unit.


Are there are any goods or activities that do not have diminishing marginal utility

Are there are any goods or activities that do not have diminishing marginal utility?


Does money have diminishing marginal utility

Does money have diminishing marginal utility?


Chapter 10 monopoly

Since goods have diminishing marginal utility and money is used to buy goods, money should also. The dollar you get that you use to buy donut number 3 is less beneficial to you than the dollar you get to buy donut number 1.


Do people get utility from things that happen after they are dead

Do people get utility from things that happen after they are dead?


Do people get utility from things that happen after they are dead1

Do people get utility from things that happen after they are dead?

If they don’t, how do you explain buying life insurance?


Chapter 10 monopoly

So how does all this explain how much of everything we buy at the store?You want to get as much benefit as you can for the money you have.


Chapter 10 monopoly

This means you want to get as many utils per dollar as you can.Shopping is trying to get the most bang for the buck.


Chapter 10 monopoly

Imagine everything in the store costs $1 and how much of each would you buy if you had $1 … $2 … $3 … $4?CandyMilk Eggs1st 14 8 62nd 10 4 53rd 7 2 3


Chapter 10 monopoly

Now what if you had $4 and candy cost $2 while the rest cost $1? Assume you can buy fractions of candy.CandyMilk Eggs1st 14 8 62nd 10 4 53rd 7 2 3


Chapter 10 monopoly

The benefit you get from buying something is determined by comparing how much you like it to its price. Of course we call how much you like it the marginal utility. So the benefit of spending a dollar on good X is MUx/Px


Chapter 10 monopoly

MUx/Px for our 3 goods when price of candy is $2 so this is the return in utils per dollar spent.CandyMilk Eggs1st 7 8 62nd 5 4 53rd 3.5 2 3


Chapter 10 monopoly

So our decision rule in choosing between 2 goods is to buy the one for which MU/P is higher. You are going to buy either an apple or orange. The MU of the apple is 12 and the orange is 4. The price of the apple is $4 and the orange is $2, which do you buy?


Chapter 10 monopoly

The apple, because you like it three times as much and it is only twice as expensive. 12 utils> 4 utils$4 $2To the economist, shopping is always and only about comparing how much you like the thing to its price.


Chapter 10 monopoly

But what if you are going to buy more than one apple or one orange? You start out buying the one with the higher MU/P, but as you buy more of it, its MU drops, and eventually its MU/P becomes lower than for the other good, then you switch over to buying the other good.


Chapter 10 monopoly

That’s exactly what happened in our candy, milk, and eggs example.When you are done with shopping, it should be the case that how much you like the last unit of each item you buy compared to its price should be close to how much you like the last unit of every other item purchased compared to its price.


Chapter 10 monopoly

If that’s not true, then you should put back the item which has an MU/P less than the other things and buy more of the item which has the higher MU/P.


Chapter 10 monopoly

Carried to its logical conclusion, this means buy your items so that all your money is spent and for everything you buy MUA = MUB = MUC = … = MUZPA PB PC PZ


Chapter 10 monopoly

What about things in the store you don’t buy at all? For those items, MU/P for even the first item you would buy would be below MU/P for the last item of everything you do buy.


Chapter 10 monopoly

Another way to look at it is to realize MU/P is the return in utils for $1 more spent on the good. Given a choice, you will always spend so that you get the most utils per dollar (the most bang for the buck).


Chapter 10 monopoly

MU is the benefit from getting one more unit, and 1/P is how many units you get for one dollar. So the benefit from one more dollars worth is MU x 1/P = MU/P.


Chapter 10 monopoly

When you head to the check-out stand, the return to spending one dollar more on anything in your card should be the same as spending one dollar more on anything else in your cart. The equation is just the mathematical way of saying this.


Chapter 10 monopoly

Question 1:The utility of an orange is higher than the utility of an apple. Can we be sure the shopper will buy the orange over the apple?


Chapter 10 monopoly

Question 2:The price of a donut and the price of an apple are the same, and the utility of the donut is higher, but the person is on a diet. Can we be sure the person will buy a donut over buying an apple?


Chapter 10 monopoly

Question 3: 1st Donut 2nd 3rd 4thMarginal 10 utils 8 utils 3 utils -1 utilsUtilityTotal 10 utils 18 utils 21 utils 20 utilsUtility Would you necessarily buy 3 donuts?


Last topic yay so how does all this create the demand curve we ve actually done it already

Last topic – Yay!!!!So how does all this create the demand curve? We’ve actually done it already.


Chapter 10 monopoly

Imagine everything in the store costs $1 and how much of each would you buy if you had $1 … $2 … $3 … $4?CandyMilk Eggs1st 14 8 62nd 10 4 53rd 7 2 3


Chapter 10 monopoly

Now what if you had $4 and candy cost $2 while the rest cost $1? Assume you can buy fractions of candy.CandyMilk Eggs1st 14 8 62nd 10 4 53rd 7 2 3


Here is the demand curve for candy

Here is the demand curve for candy.

P

$2

$1

D

0

Q

0

12


Chapter 10 monopoly

At a dollar a piece, you buy candy until the return to another dollars worth of candy is below whatever else you could spend that money on.


Chapter 10 monopoly

Now the price doubles to $2. You only get half as much candy for a dollar, so you are getting half the return in utils for that dollar spent on candy. Better to spend that money on other things (more bang for the buck).


Chapter 10 monopoly

But as you buy less candy, the MU of the candy rises till finally a dollars worth of candy is equal in utils to everything else again, and that is the new smaller amount of candy you buy.MUA = MUB = MUC = … = MUZPA PB PC PZ


Mu a mu b mu c mu z p a p b p c p z

MUA = MUB = MUC = … = MUZPA PB PC PZ

P

$2

$1

D

0

Q

0

12


Https www youtube com watch v w wu q9wq8i list rdw wu q9wq8i

https://www.youtube.com/watch?v=W_WU-q9wQ8I&list=RDW_WU-q9wQ8I

And now … 40 hours of microeconomics summed up in 5 minutes.


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