Demand and Supply CHAPTER 4 EYE ONS DemandLaw of DemandSupply Demand curveLaw of Market ForcesSupply curve Demand ScheduleLaw of SupplySupply schedule

Demand and Supply CHAPTER4EYE ONS

Demand Law of Demand SupplyDemand curve Law of Market Forces Supply curveDemand Schedule Law of Supply Supply scheduleQuantity demanded Minimum wage law Quantity suppliedChange in demand Change in supplyChange in quantity demanded Change in quantity suppliedShortage/excess demand Shortage/excess supply

Equilibrium price Complement Inferior GoodEquilibrium quantity Complement in production Normal GoodMarket equilibrium Substitute Price ceiling/cap

Substitute in production Price floor

Using Demand and Supply

The demand and supply model is going to be a big part of the rest of your life!

1.You will use it again and again during your economics course. • D/S model is one of the major economic tools• Having a firm grasp of it will bring an immediate payoff.

2.You better appreciation how your economic world works• By understanding the laws of D/S • By being aware of how prices adjust to balance the two

opposing forces

Example: When you hear someone complaining about a price hike and blaming it on someone’s greed think about •The law of market forces and how demand and supply determine price•You will know how supply and demand influence the price of clothing, music, food, and many other items that you purchase

COMPETITIVE MARKETS

In this chapter, we study a competitive market that has so many buyers and so many sellers that no individual buyer or seller can influence the price.

What isa market?

• Law of Demand

• price = Qty Demanded

• Quantity Demanded:

• Amount willing and able to BUY during a specific period at a specific price

• Per unit of time (2 bottles a day)

• Demand

• Relationship between Qty Demanded and Price

• List of quantities at different prices

• Portrayed as 1) schedule or 2) curve

Demand

CHAPTER 4

DEMAND – Schedule and Curve

In Consumption

• Change in Quantity Demanded:

• Price change of given good results in a change in buying habits

• Change in Demand

• Any Influence Other than Price results in a change in buying habits

1. Price of related goods

• Substitute good – a good that can be consumed in the place of another good

• price of substitute good = Qty Dem for that good

• price of substitute good = Demand for other good

• Complement good – a good that can be consumed with another good

• price of complement good = Qty Dem for that good

• price of complement good = Demand for other good

Changes in Demand

CHAPTER 4

Apples & oranges

Ice cream & choc syrup





2. Income

• Normal good : income = demand

• Inferior good : income = demand

3. Expectations

• Expected future prices = ‘buy it now’ = demand

• Expected future income = ‘take a vacation’

Changes in Demand

CHAPTER 4

BMWs or Ramon Noodles





4. Number of Buyers

• # of buyers = demand

5. Preferences

(Demand for one item and for another item)

• Better information: ‘Smoking’ demand for cigarettes and demand for nicotine patches

• Introduction of new good: Introduction of MP3’s

demand for CD’s, demand for internet service

Changes in Demand

CHAPTER 4

CHAPTER 4

Changes in Demand

A Change in the Demand for Roses

In a normal month, the price is $40 a bouquet and 6 millionbouquets are sold.

In February, the equilibrium price rises and the equilibrium quantity increases.

Valentine’s Day in February the demand for roses increases and the demand curve shifts rightward.

• Law of Supply

• price = Qty Supplied

• Quantity Supplied:

• Amount willing and able to SELL during a specific period of time at a specific price

• Per unit of time (2 bottles a day)

• Supply

• Relationship between Qty Supplied and Price

• List of quantities at different prices

• Portrayed as 1) schedule or 2) curve

Supply

CHAPTER 4

SUPPLY – Schedule and Curve

• Change in Quantity Supplied:

• Price change of given good results in a change in selling plans

• Change in Supply

• Any Influence Other than price results in a change in selling plans

1. Price of related goods

• Substitute good – a good that can be produced in the place of another good

• price of substitute good = Qty Supplied for that good

• price of substitute good = Supply for other good

• Complement good – a good that can be produced with another good

• price of complement good = Qty Supplied for that good

• price of complement good = Supply for other good

Changes in Supply

CHAPTER 4

In Production

SUV &

Truck

Cream & Skim milk


• Price change of given good results in a change in selling plans


• Any Influence Other than price results in a change in selling plans

2. Prices of resources and other inputs

• price of resource = supply

3. Expectations

• Expected future prices = supply

‘suppliers stock up now to get future high prices’

Changes in Supply

CHAPTER 4

Steel Crisis

Orange JuiceFrost kills FL oranges


• Price changes result in a change in Selling plans


• Any Other Influence results in a change in selling plans

4. Number of Sellers

• # of sellers= supply

5. Productivity – Output per unit of Input

• Technological Change: cost

• Improvements = productivity and supply

• Natural Events: cost

• hurricanes = productivity and supply

Changes in Supply

CHAPTER 4

CHAPTER 4

Changes in Supply

A Change in the Supply of Flat Panel TVs

A few years ago, the price of a 42-inch flat panel TV was $6,000.

The equilibrium quantity increased.

Advances in technology have lowered the costof production and the supply increased.

The equilibrium price decreased.

The quantity demanded increased.

CHAPTER 4

Market Equilibrium

• Equilibrium is when Qty Demanded = Qty Supplied

Market Equilibrium• Equilibrium is when Qty Demanded = Qty Supplied

Shortage = excess demand Surplus = Excess supply

CHAPTER 4

Shortage = Price rises

Until market is in equilibrium

Surplus = Price falls

CHAPTER 4

Effects of Changes in Demand• When equilibrium is disturbed, the market immediately begins to adjust

(short-term) and eventually arrives at a NEW equilibrium (long-term)

MARKET EQUILIBRIUM

Event: A new zero-calorie sports drink is invented.

To work out the effects on the market for bottled water:

1. Does the event change demand or supply?• The new drink is a substitute for bottled water, so

the demand for bottled water changes

2. Does the event Increase or Decrease demand or supply?

• The demand for bottled water decreases, the demand curve shifts leftward.

3. What are the new equilibrium price and quantity and how have they changed (increase or decrease)?

• What are the new equilibrium price and equilibrium quantity and how have they changed?

Effects of Change in Demand … in action

MARKET EQUILIBRIUM – Bottled Water Market

Figure 4.7(b) shows theoutcome.

1. A decrease in demand shifts the demand curve leftward.

2. At $1.00 a bottle, there is a surplus, so the price falls.

3. Quantity supplied decreases along the supply curve.

4. Equilibrium quantity decreases.

MARKET EQUILIBRIUM

When demand changes:

• The supply curve does not shift.

• But there is a change in the quantity supplied.

• Equilibrium price and equilibrium quantity change in the same direction as the change in demand.

CHAPTER 4

Effects of Changes in Supply• When equilibrium is disturbed, the market immediately begins to adjust

(short-term) and eventually arrives at a NEW equilibrium (long-term)

MARKET EQUILIBRIUM

Event: Drought dries up some springs in the United States.

To work out the effects on the market for bottled water:

1. Does the event change demand or supply?• Drought changes the supply of bottled water.

2. Does the event Increase or Decrease demand or supply?• The supply of bottled water decreases, the supply

curve shifts leftward.

3. What are the new equilibrium price and quantity and how have they changed (increase or decrease)?

• What are the new equilibrium price and equilibrium quantity and how have they changed?

Effects of Change in Demand … in action

MARKET EQUILIBRIUM – Bottled Water Market

Figure 4.8(b) shows theoutcome.

1. A decrease in supply shifts the supply curve leftward.

2. At $1.00 a bottle, there is a shortage, so the price rises.

3. Quantity demanded decreases along the demand curve.

4. Equilibrium quantity decreases.

MARKET EQUILIBRIUM

When supply changes:

• The demand curve does not shift.

• But there is a change in the quantity demanded.

• Equilibrium price changes in the same direction as the change in supply.

• Equilibrium quantity changes in the opposite direction to the change in supply.

CHAPTER 4

Changes in Both Demand and Supply

• We cannot say what happens to PRICE or QUANTITY without knowing the MAGNITUDE of the changes

When two events occur at the same time, work out how each event influences the market:

1. Does each event change demand or supply?

2. Does either event increase or decrease demand or increase or decrease supply?

3. What are the new equilibrium price and equilibrium quantity and how have they changed?

CHAPTER 4


CHAPTER 4


CHAPTER 4


CHAPTER 4


CHAPTER 4


SUPPLY CURVE UNCHANGED

SUPPLY CURVESHIFTS TO THE RIGHT

SUPPLY CURVE SHIFTS TO THE LEFT

DEMAND CURVE UNCHANGED

Q unchangedP unchanged

Q increasesP decreases

Q decreasesP increases

DEMAND CURVESHIFTS TO THE RIGHT Q increases

P increases

Q increasesP increases ordecreases

Q increases or decreases P increases

DEMAND CURVESHIFTS TO THE LEFT

Q decreasesP decreases

Q increases or decreasesP decreases

Q decreasesP increases ordecreases

CHAPTER 4

Price Rigidities • What happens if the Price does NOT adjust

THREE COMMON REASONS WHY PRICE DOES NOT ADJUST

• Price Floor – lowest LEGAL price to trade or sell a good, service or factor of production

• Price Ceiling – highest LEGAL price to trade or sell a good, service or factor of production

• Sticky Price – buyer and seller agree on price for a fixed period or seller infrequently changes price in given market

CHAPTER 4

Price Rigidities – Price Floor• What happens if the Price does NOT adjust

Price Floor [minimum wage]

• Price Floor set ABOVE the equilibrium point DOES effect the market

• Price Floor set BELOW the equilibrium point DOES NOT effect the market

• Don’t forget to quantify the effects

• Surplus of 4000 workers

Minimum Wage

CHAPTER 4

Price Rigidities – Price Ceiling• What happens if the Price does NOT adjust

Price Ceiling [parking spaces]

• Price Floor set ABOVE the equilibrium point DOES NOT effect the market

• Price Floor set BELOW the equilibrium point DOES effect the market

• Don’t forget to quantify the effects

• Shortage of 2000 parking spaces

Rent ControlCollege Tuition

CHAPTER 4

Price Rigidities – Sticky Prices

• Sticky Price = Buyer and Seller AGREE on a price for a PERIOD of time

• Long-term contracts

• Labor unions

• Interest rates

• Commodity trade

• Prices DO adjust but, NOT quick enough to avoid shortages and surpluses

The federal government’s Fair Labor Standards Act sets the minimum wage, but most states set their own minimum wage rate at a higher level than the federal minimum.

The minimum wage creates unemployment.

But how much unemployment does it create?

Until recently, most economists believed that a 10 percent increase in the minimum wage rate decreased teenage employment by between 1 and 3 percent.

The Federal Minimum Wage

David Card and Alan Kruger claim that a rise in the minimum wage rate increases the employment rate of low-income workers.

They suggest three reasons:

1. Workers become more conscientious and productive.

2. Worker are less likely to quit, so costly labor turnover is reduced.

3. Managers make a firm’s operations more efficient.


But most economists are skeptical about these ideas.

They suggest:

1. With labor more productive and lower turnover costs, firms would willingly pay a wage equal to the minimum wage.

2. Firms anticipate a rise in the minimum wage, so they cut the number of workers ahead of the rise in the minimum wage. Unemployment does not increase after a rise in minimum wage rate.

3. Looking at employment misses the effect on the supply of labor—a higher minimum wage increases the supply as people drop out of high school to look for work.


CHAPTER 4Summary: Key Points in the ArticleGiant retailer Wal-Mart upended the market for flat-panel televisions last November when it made the decision to drop price below the $1,000 mark for the 42-inch screens. The impact on Wal-Mart was minimal since the stores quickly sold inventories and replenished with a flood of new flat panels from new factories. However the impact on the company’s competitors was dramatic. Circuit City Stores, Tweeter Home Entertainment Group, and CompUSA have all been forced to close stores and lay off employees as the companies price-matched Wal-Mart’s televisions. While Wal-Mart’s move did catch some off guard, many analysts pointed out the similar impact on grocery store chains when Wal-Mart entered the grocery business. Others noted that several toy chains entered bankruptcy largely due to Wal-Mart’s fierce price cutting. Wal-Mart maintains that consumers benefit due to lower prices. Wal-Mart’s competitors hope that at least a few customers will continue to want their televisions installed and might prefer a wider selection.

Analyzing the NewsWhen Wal-Mart slashes prices or enters a new market the company has the same impact as an increase in supply as shown above. A new market participant of that size forces competitors to emulate and lower prices. However, profit margins get competed away to the point where the least efficient eventually go out of business.

CHAPTER 4Summary: Key Points in the ArticleThe price of oil topped $72 a barrel on the heels of news that eight foreign oil workers were kidnapped from a Nigerian oil drilling rig. Iran’s uncertain nuclear future also created additional uncertainty about the political stability of another oil rich region. Recent Nigerian militant violence includes blowing up oil pipelines and other acts of violence designed to disrupt the country’s oil production. To date, the Nigerian violence has resulted in the shut-in of 500,000 barrels of oil per day at a time when global production only exceeds consumption by about two million barrels of oil per day. Gasoline futures surged as well due to a production slowdown resulting from a Texas refinery that sustained lightning-related fire damage and subsequent disruption in output. Elsewhere, OPEC decided to leave its output quotas unchanged. Growth in global oil demand slowed a little but remains strong with U.S. gasoline demand up about one per cent over the same period last year.

Analyzing the NewsA number of factors other than a change in price have impacted the potential supply of oil. These all culminate in a decrease in oil supply, or expected decrease, and subsequent increase in the price of oil.

CHAPTER 4Summary: Key Points in the ArticleCocoa futures are riding high due to drought, political unrest, and changing consumer tastes. Two major factors have combined to restrict the supply of cocoa; a drought in Western Africa and civil unrest in the Ivory Coast. The Ivory Coast is the planet’s biggest producer of cocoa. The result is a 5.5% drop in the production of cocoa over the previous year. Cocoa prices have responded accordingly and are near a three year high with prices increasing by 44% since November 2005. The demand side is also affecting prices. Consumer tastes have shifted toward darker chocolates and dark chocolate requires more cocoa to manufacture. The change in preference is driven partially by health reasons. Dark chocolates are higher in antioxidants and considered to be healthier than other chocolates. Some studies link dark chocolate consumption to lower blood pressure. Since dark chocolates are also higher margin products, manufacturers have been happy to oblige. However, the combined effect of the supply and demand factors is a certain recipe for higher cocoa prices.

Analyzing the NewsNote that both the supply and demand shifts would result in a higher cocoa price taken in isolation. Since all three factors have hit this market simultaneously, it is not surprising that prices have risen as rapidly and are substantial increases.

CHAPTER 4Summary: Key Points in the ArticleThe rising price of gold as a jewelry input has pushed many consumers to postpone jewelry purchases. The result is that gold traders are becoming more cautious about the current price level until it is determined how much of the current $900 price is the result of inflation hedging and how much is derived from jewelry demand. Meanwhile global output fell about 1 percent last year as production costs increased. Many traders indicate that jewelers have evaporated from the gold market. Meanwhile many jewelry items are being melted down and returned to the market as scrap to take advantage of the current high prices. Much of the demand appears to be investor driven as stocks tumble and interest rates fall.

Analyzing the NewsGold prices are being pushed by investor demand for gold increasing while at the same time jewelry demand for gold is falling. The net impact, coupled with net supply changes due to lower mining production and higher scrap production, has settled prices above the $900 mark. However, gold traders are having difficulty forecasting direction and the ultimate settling price.

CHAPTER 4Summary: Key Points in the ArticleProduction problems, coupled with higher than expected consumer demand, are contributing to shortages of certain toys this holiday season. Many of the Chinese factories are experiencing labor shortages as high-tech job creation causes many Chinese to move off of the assembly line. Power outages have also contributed to lower productivity in the manufacturing regions of southern China. Unfortunately these problems came at the wrong time and have limited supplies of numbers of toys including Sony’s PlayStation 3. In addition to the supply problems, consumer demand was underestimated. Last year’s sales data were extrapolated to this year and many retailers placed very conservative orders. The limited supply and underestimated demand has created a real shortage of some toys. The result is a hot secondary market on Ebay for many toys such as the PlayStation 3 and Mattel’s TMX Elmo. The Elmo retails for $40 but is fetching $65 on Ebay.

Analyzing the NewsNote that at price P there are more toys demanded than there are toys supplied. This shortage, particularly in game consoles, can be best visualized by the fact that some consumers are buying game consoles at store prices and selling them on Ebay for a large profit. The Ebay price would be equivalent to the price at equilibrium point A.

Documents

Demand and Supply CHAPTER 4 EYE ONS DemandLaw of DemandSupply Demand curveLaw of Market ForcesSupply curve Demand ScheduleLaw of SupplySupply schedule