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Steven LandsburgUniversity of Rochester
Chapter 1
Supply, Demand, and Equilibrium
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for
classroom use.
Price Theory
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KEYWORDSChapter 1
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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Words to Know
• demand• demand curve• econometrics• economic incidence• equilibrium point• excise tax• fall in demand• fall in supply• law of demand• law of supply• legal incidence• price to demanders
• price to suppliers• quantity demanded• quantity supplied• rise in demand• rise in supply• sales tax• satisfied• supply
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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Introduction
• Telling is not learning.– discover supply and demand
• Economic consequences– poor weather conditions– substitute goods and services– taxation
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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Introduction
• Interplay of supply and demand• Supply and demand analysis
– Consumers– Producers– Responsiveness of prices and quantities to
variety of changes in economic environment
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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DEMANDSection 1.1
Landsburg, Price Theory, 8th edition
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Page 7
Law of Demand
• When price of a good goes up, people buy less of good
• Downward sloping demand curve
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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Demand
• Demand– A family of numbers that lists the quantity
demanded corresponding to each possible price
– Refers to the curve itself
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 10
Quantity Demanded
• Quantity Demanded– Amount of a good consume at a given price– Change in price means a change in quantity
demanded• Movement along the demand curve
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 11
Demand Curve
• Graph illustrating demand– Price on the vertical axis– Quantity demanded on the horizontal axis
• Representation of the demand schedule
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 12
Changes in Demand
• Price change does not lead to change in demand
• Purchasing rule changes lead to demand changes– Entire curve shifts
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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Shifting Demand
• Fall in Demand– Decision made by demanders to a buy a
smaller quantity at each given price– Leftward shift of demand curve
• Rise in Demand– Decision made by demanders to a buy a
larger quantity at each given price– Rightward shift of demand curve
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 14
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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Sales Tax Example
• Impose tax on consumers– Paid directly to the government
• Less desirable to buy the taxed good or service at every given price
• Demand shifts left and downward
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 16
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 17
Market Demand
• Quantity associated with a given price is the total number of that good or service that the group members would demand
• Slopes downward (similar to the individual demand curve)
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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Shape of the Demand Curve
• Steeply-sloped demand curve– Small change in price leads to small change
in quantity demanded• Flat demand curve
– Small change in price leads to large change in the quantity demanded
• Important to producer of good or service
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 19
Econometrics
• Statistical techniques used by economist to resolve questions about slopes of various demand curves
• Based on direct observations in marketplace– Ex. Demand for murder– Ex. Demand for reckless driving
• Wide scope of economics– Allows for other investigations as well
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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SUPPLYSection 1.2
Landsburg, Price Theory, 8th edition
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Page 21
Law of Supply
• When the price of a good goes up, the quantity supplied goes up
• Leads to a upward sloping supply curve
Landsburg, Price Theory, 8th edition
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Page 22
Supply
• Supply– Family of numbers giving the quantities supplied at
each price– Changes in anything other than price changes supply
• Shifts entire curve
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 23
Quantity Supplied
• Quantity Supplied– Amount of a good that suppliers will provide at a given
price– Changes if the price changes
• Movement along the curve
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 24
Changes in Supply
• Rise in Supply– Increase in quantities that supplier will provide
at each price– Rightward shift of supply
• Fall in Supply– Decrease in quantities that supplier will
provide at each price– Leftward shift of supply
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 25
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 26
Excise Tax Example
• Impose a tax on producers– Paid directly to the government
• Less desirable to produce the taxed good or service at every given price
• Supply shifts left and upward
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 27
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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EQUILIBRIUMSection 1.3
Landsburg, Price Theory, 8th edition
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Page 29
Equilibrium
• Actual price determined by interaction between demanders and suppliers– Demanders cannot purchase more than
suppliers willing to sell them– Suppliers cannot sell more than demanders
willing to buy
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 30
Equilibrium Point
• Point where supply and demand curves intersect– Price where quantity demanded equals
quantity supplied• Demanders and suppliers satisfied
– Able to behave as one wants to, taking market prices as given
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 31
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 32
Changes in the Equilibrium Point
• Never look at price and quantity• Look at effect change has on demand
curve and supply curve• Common mistakes arise as look at
equilibrium– Supply, demand, and equilibrium misused at
times– Check validity of information
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 33
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 34
Effect of Sales Tax
• Sales tax of x¢ per item causes equilibrium price to fall by some amount less than x¢ per item
• Price to suppliers not same as price to demanders (price plus sales tax)
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 35
Effect of Excise Tax
• Excise tax of x¢ per item causes the equilibrium price to rise by some amount less than x¢ per item
• Price to suppliers (price minus excise tax) not same as price to demanders
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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Comparing Two Taxes
• Economic Incidence – the division of a tax burden according to who actually pays the tax
• Legal Incidence – the division of a tax burden according to who is required under the law to pay the tax
• The economic incidence of a tax independent of its legal incidence
• Ex. Social Security tax
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
Page 37
Landsburg, Price Theory, 8th edition
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.