Class 30 - Elasticity and Supply

 Income Elasticity of Demand:

%change in QD / %change in income

-how much consumption changes with income

            -income goes up, number is positive = normal good – buy more as income goes up

            -income goes up, number is negative = inferior good – buy less when income goes up

Ex. Income is $50,000 and you spend $500 on a good and M =2.

            If income increases by 20%, you spend 40% more on that good

            If change in income is $10,000, you spend $200 more on that good.

Cross Price Elasticity:

Cross price elasticity = positive = goods are substitutes

                                  = negative = goods are inferior

Pizza / burritos. Price of pizza increases = demand for burritos increases. = substitutes

SUPPLY

More money = produce more

            Cost = tied to an action (not just a thing)

                    = tied to a person

It costs more to make a bike than a table because bike resources are valued more and the people who make bikes have an easier time finding jobs. Opportunity cost of table resources are less than the bike because people bid away resources.

Quantity supplied vs law of supply:

Quantity supply = amount of good that firms are willing/able to produce at a particular price

Law of Supply = price of a good rises = sellers make more.