Module 1
why is your demand curve downward sloping?
diminishing marginal benefit
diminsihing marginal benefit
each additional item yeilds a smaller marginal benefit that the previous item
what holds the potential top make everyone better off
efficient outcomes
what is important but ignored by efficiency
equity
cost benefit principle
evaluate full set of ccosts and benefits of any choice pursue only those3 choices whose benefits are at least as large as costs
marginal benefit
extra benefit from one unit (of goods purchased, hours studied etc. )
positive analysis
fact based Ex: the minimum wage is $7.25
market demand curve
graph plottig the total quantity of an item demanded, bu the entire market, at each price (sum of quantity demanded by each person)
market supply curve
graph plotting the total quantity of an item supplied by entire market
deadweight loss
how far economic surpluys falls below the efficient outcome economic surplus at efficient quantity - actual economic surplus
consumer surplus
the economic surplus you get from buying something consumer surplus = marginal benefit (willingness to pay) - Price
producer surplus
the economic surplus you get from selling something price - marginal cost
efficient outcome
the efficient outcome yields the largest possible economic surplus
marginal cost
the extra cost form one extra unit
supply curve also represents what
the marginal cost curve
economic efficiency
the more economic surplus that's generated, the more efficient the outcome
if there are various costs of taking a walk in the park, each at different values (e.g. $5, $8, $13, $15) what would be the opportunity cost of taking a walk in the park
the next best alternative , $15
equilibrium price
the price at which the market is in equilibrium
Law of Demand
the quantity demaded is higher when the price is lower -- holding other things constant
equilibrium wuantity
the quantity demanded and supplied at equilibrium
efficient quantity
the quantity that produces the largest possible economic surplus
if supply equation is
Qs = 40 + 5P
You are considering whether you should go out to dinner at a restaurant with your friend. The meal is expected to cost you $40, you typically leave a 20% tip, and an Uber will cost you $5 to get there. You value the restaurant meal at $20. You enjoy your friend's company and are willing to pay $30 just to spend an evening with her. If you did not go out to the restaurant, you would eat at home using groceries that cost you $8. How much are the benefits and costs associated with going out to dinner with your friend? Should you go out to dinner with your frien
The benefits are $58. You receive $20 worth of benefit from the restaurant meal itself. You also receive $30 worth of benefit from having dinner with your friend. Additionally, by not eating at home, you will save $8 on the groceries you would have purchased. The total benefit, therefore, would be $58. The costs are $53. The price of the meal will be $40. You will also leave a 20% tip, which adds another $8. Your car fare is $5. So, the total cost would be $53. The total benefits are equal to $58 and the total costs are equal to $53. So, going to dinner with your friend will yield $5 worth of economic surplus and you should go out to dinner with your friend
efficient production
producing a given quantity of output at the lowest possible cost
how can we visualize opportunity costs
production possibilities frontier (PPF)
the rational rule for markets
propdcue until marginal benmefit equal marginal cost
equilibrium
quantitiy supplied equals quantitiy demanded
Rational Rule for Sellers in Competitive Markets
sell one more item if the price is greater than (or equal to) the marginal cost
factors that shift both individual and market demand curves
1. income (normal versus inferior) 2. preferences 3. prices of related goods 4. expectations 5. congestion and network effects
five sources of market failrue
1. market power (micro) 2. externalities (micro) 3. information problems (micro) 4. irrationality (micro) 5. government regulations (trarde)
solving market equilibrium with equations
1. set the quantity demanded and quantity supplied equal to eachother 2. Solve for P 3. Substitute the value of P into either equation 4. Solve for Qd or Qs
critiques of economic efficiency
Crigtique 1: distribution matters, so its also importatn to account for equity Critique 2: willingness to pay reflects ability to pay, not just marginal benefit Critique 3 the means matter, not just the ends
demand equation
Qd = 100 - 10d as prices changes by $1, Qd changes by 10 units
economic surplus of Ivan and Samanthas trade what is the total
Ivan's: 55,000-45,000 Samanthas': 72,000-55,000 total: 27,000
Ivan has inherited his mother's 1963 Chevrolet Corvette, which he values at $45,000. He decides that he might be willing to sell it so he posts it on Craigslist for $55,000. Samantha is interested and willing to pay up to $72,000
Ivans benefit: $55,000 Ivans cost: benefits of car $45,000 Samantha benefit: $72,000 willing to pay Samantha cost: $55,000 Both would agree to the exchange
Demand function
Qd = f(P)
sunk cost
a cost that has been incurred and cannot be reversed, not an opportunity cost
individual demand curve
a graph plotting the quantity of an item that someone plans to buy at each price "what quantity should I buy at this price?"
four core principles for analyzing decisiosn
cost benefit principle opportunity cost principle the marginal principle the interdependence principle
what choices require a trade off
all choices
what is a perfectly competitive market
all firms in the industry sell an identical good there are many buyers and sellers, each of whom is small relative to the size of the market
efficient allocation
allocating goods to create the largest economic surplus efficient allocation requries that each good goes to the person who will receive the highest marginal benefit from it
equity
an outcome yields greater equity if it results in a fairer distribution of economic benefits
voluntary exchange
buyers and sellers exchange money for goods only if they both want to ensures both buyer and seller enjoy gains from trade
normative analysis
bvalue based ex: the minimum wage should be $15
movement along the demand curve
caused by price change
economic surplus
consumer surplus + producer surplus = marginal benefit - marginal cost
which principle is useful for "either/or" choices
cost-benefit
what is the marginal principles rational rule
if something is worth doing, keep doing it until your marginal benefits equals your marginal costs
when does economic surplus rise
if the gains to those who are helped by policies are greater than the declines in surplus among those who are harmed
what shift individual and market supply curves
input prices productivity and technology prices of related outputs expectations
which principle is useful for "how many" decisions
marginal principle
scarcity
occurs because resources are limited
market failure
occurs when the forces of supply and demand lead to an inefficient outcome
law of supply
the tendancy fro the quantity supplied to be higher when the price is higher supply curves are upward sloping because the higher the price, the higher the quantity supplied
what factor only shifts the market supply curve
the type and number of seller
economic surplus
total benefits minus the total costs
economic surplus
total benefits minus total costs flowing from a decision
opportunity cost:
true cost of something is the next best alternative you must give up to get it
factors that only shift market demand curves
type and number of buyers
produce inside vs outside of PPF
you can produce in something => ineffieicent use of your resources can only produce outside of PPF if you change something
interdepedence principle
your best choice depends on the other choices you make, the choices others make, developments in other markets, and expectations about the furture