Econ Chapter 3: Demand & Supply
Equilibrium
A situation in which opposing forces balance each other. (Occurs in a market when price balances the plans of buyers and sellers)
Equilibrium quantity
Quantity bought and sold at equilibrium price
A substitute is a good that is _____ another good, and a complement is a good that is _____ another good.
consumed in place of; consumed together with
Equilibrium price
Price at which the quantity demanded = quantity supplied
The money price of a pack of frozen waffles is $1.75, and the relative price of a pack of frozen waffles in terms of burritos is 2.5 packs of frozen burritos per pack of frozen waffles. What is the money price of a pack of frozen burritos?
$0.70 Relative price = money price/money price of alt. 2.5=1.75/x 2.5x= 1.75 x=1.75/2.5=0.7
Substitution effect
(BUY SOMETHING CHEAPER) When relative price (opportunity cost) of a good or service rises, people seek substitutes for it, so the quantity demanded of the good or service decreases.
Income effect
(CANNOT AFFORD IT) When price of a good/service rises relative to income, people cannot afford all the things they previously bought, so quantity demanded of the good/service decreases
Suppose that demand increases by 200 batteries a day and supply decreases by 100 batteries a day. What is the new equilibrium price of a battery and what is the new equilibrium quantity of batteries?
+200 to all demands listed -100 from all supplies listed Find numbers where they are equal
Six main factors that change the supply of a good (shift)
1) Prices of factors of production 2) Prices of related goods produced 3) Expected future prices 4) The number of suppliers 5) Technology 6) State of nature
Why does price change the quantity demanded?
1) Substitution Effect 2) Income Effect
Six main factors that change demand
1) The prices of related goods 2) Expected future prices 3) Income 4) Expected future income and credit 5) Population 6) Preferences
If you demand something, then you ...
1. Want it 2. Can afford it 3. Have made a definite plan to buy it
If the money price of a cup of coffee is $1 and the money price of gum is 50 cents per pack, then the relative price of coffee in terms of gum is _____.
1/0.50 = 2 packs per cup
Money price
Amount of money needed to buy it
Quantity demanded
Amount that consumers plan to buy during a particular time period and at a particular price
Market
Any arrangement that allows buyers and sellers to get information and do business with each other
We observe a rise in the price of tomatoes and a decrease in the quantity of tomatoes that producers sell. The most likely explanation is that ... A) The market for tomatoes is unpredictable B) The law of demand applies to tomatoes but the law of supply does not C) The law of supply applies to tomatoes but some other influence on selling plans decreased the supply of tomatoes D) The supply curve is downward sloping
C) The law of supply applies to tomatoes but some other influence on selling plans decreased the supply of tomatoes
If demand and supply change in the same direction, we _____ the direction of the equilibrium quantity and _____ the direction of change of the equilibrium price.
Can predict; cannot predict
Ramen noodles and rice are substitutes. If the price of ramen noodles decreases, how does the demand for rice change? If the price of ramen noodles decreases, the demand for rice will _____.
Decrease, and the demand curve for rice will shift leftward
At a price above equilibrium price, a surplus forces the price _____. At a price below equilibrium price, a shortage forces the price _____.
Down; Up
Quantity supplied
Good/service is the amount that producers plan to sell during a given time period at a particular price
Competitive market
Has many buyers and sellers, so no single buyer or seller can influence the price
Which are a change in QS, which are a change in S: I) Farms are selling less chicken because the price of turkey has increased. II) Farms are selling less chicken because the price of chicken has fallen. III) Farms are selling more chicken because the price of chicken has risen. IV) Farms are selling more chicken because the cost of chicken feed has fallen.
I and IV are changes in supply II and III are changes in quantity supplied
If demand and supply curves change in the same direction: An Increase in D and S curve _____ equilibrium quantity. A decrease in D and S curve _____ equilibrium quantity. Change in equilibrium price is uncertain.
Increase Decrease
An increase in the price of wood planks, a substitute in production of wood beams, will _____ the equilibrium price of wood beams and _____ the equilibrium quantity of wood beams.
Increase; decrease
Stephan graduates from college and his income increases to $20,000 a year. Nothing else changes. Stephan decreases the quantity of ketchup and potato chips that he buys and increases the quantity of ski trips that he buys. For Stephan, _____.
Ketchup and potato chips are inferior goods
Luxury car makers forecast a decrease in households' incomes and an increase in the ease in which credit can be obtained. What do you predict will happen to the demand for luxury cars today?
Might increase, decrease, or remain the same
If the price of a taco rises, a _____ the supply curve occurs. If any factor that influences selling plans other than the price changes, then a _____ the supply curve occurs.
Movement up along; shift of
The law of supply
Other things remaining the same, the higher the price of a good, the greater is the quantity supplied. The lower the price of a good, the smaller is the quantity supplied
Law of demand
Other things remaining the same... the higher the price of a good, the smaller is the quantity demanded. The lower the price of a good, the higher is quantity demanded
If demand and supply curves change in opposite directions: An increase in D curve, and decrease in S curve _____ equilibrium price. A decrease in D curve, and increase in S curve _____ equilibrium price. Change in equilibrium quantity is uncertain.
Raises Lowers
Relative price
Ratio of its money price to the money price of the next best alternative good (it's opportunity cost)
Demand
Reflects a decision about which wants to satisfy
An increase in the demand for rice brings a _____ in the price of rice and _____ in the quantity of rice supplied
Rise; increase
Choose the correct statements about competitive markets. 1) A single buyer in a competitive market cannot influence the price. 2) Competitive markets exist for goods, services, money, factors of production, and inputs. 3) In a competitive market, prices are eventually driven down to zero. 4) A competitive market must be a global market.
Statements 1 and 2 are correct
What is the equilibrium price of a milkshake on the schedule?
The price at which quantity demanded and quantity supplied are equal.
Along the supply curve, _____.
The price changes but all other influences on producers' planned sales remain the same
If the price of a granola bar falls, with all other influences on buying plans remaining the same, in the market for granola bars _______.
The quantity of granola bars demanded increases
Wants
Unlimited desires/wishes people have for goods and services
A shortage of a good forces the price _____.
Up
An RV is a normal good. If income is expected to increase next year, you predict that the demand for RVs _____ now.
Will increase
A demand curve is also a willingness-to-pay curve
Willingness to pay measures marginal benefit