Saturday, September 30, 2017
Saturday, September 16, 2017
|Elasticity is all about the changes.|
Elasticity Cheat Sheet here
**You must know the determinants.
Determinants of Inelastic Demand?
The price of my favourite candy bar increased by 10%, I didn't notice.
(My demand for my favourite candy bar is inelastic as a 10% price increase is such a low amount I don't notice it or let it change my preference)
The price of black beans increased by 20% and I don't care.
(I love black beans and consider them a necessity in my kitchen. My demand for Shitto is inelastic)
I've eaten a lot of Shitto in my life.
I'm a Shitto magnet
Ok, that's enough.
Short (Time) Horizon
Sometimes you don't have the capacity to be shopping around for the lowest price.
(My demand for a toilet is inelastic when I have to go bad)
If a good is addictive then your desire for that good doesn't diminish very much if the price increases.
Therefore your demand for the good is inelastic.
Low Number of Substitutes
Often if something is unique or if the choices are limited then your demand will be inelastic.
**Know that the Inelastic Demand curve is drawn very steeply.
|When Supply decreases the price for Petrol increases by a larger amount that the Quantity Demand,|
There is no close substitute for Petrol, therefore the Demand is Inelastic
** Know that any and every demand curve has an elastic section and an inelastic section.
|Recognise, that the inelastic section of the curve is at the lower prices, this often causes confusion but it shouldn't,,, |
at low prices a 10% change in the price does' t really affect the amount we buy,, or our quantity demand.
**Know that Inelastic Demand means that the percentage change in quantity demand is less than the percentage price change.
|We can see that with a price increase, quantity demand has changed less|
When you are demand inelastic you just don't react as much to a price change
** Know Perfectly Inelastic demand is that no matter the Price change (great or small) the same amount of a good will be bought.
** Understand that the PED of a perfectly inelastic curve is zero and that the PED for a relatively Inelastic demand is between zero and 1.
Perfectly Inelastic PED is zero (0)
This makes sense in that with a price change there is a (0) % change in the quantity demanded
Relatively Inelastic Demand is a number between zero (0) and 1
Inelastic Demand = 0 < PED < 1
This makes sense as the % change in quantity demand is less than the % change in price
Thursday, September 14, 2017
Wednesday, September 13, 2017
Demand & Supply Equilibrium
Kezia from Colorado asks me to take a shot at explaining just what the AP exam is looking for when it comes to Equilibrium.
Demand and Supply equilibrium, is with given shifts in demand and supply we can then tell what has happened to the price and quantity of a specific good.
First what we know:
Demand Decreases or Increases - What happens to the price and quantity?
When the demand shifts left (decreases) then the Price & Quantity decreases.
When demand shifts right (increases) then Price & Quantity increases.
Ok so far?
Supply Increases or Decreases - What happens to price and quantity?
When the supply shifts right (increases) then the Price decreases & Quantity increases.
When supply shifts left (decreases) then Price increases & Quantity decreases.
Demand Increases and then Supply Increases, not once , not twice, but three times.
(Work with me, I'm trying to make a point)
Demand & Supply curve are originally in equilibrium at Point E1
The original Equilibrium point is at (E1)
Price is at PE1
Quantity is at QE1
Demand Increases to D2
Demand Shifts Right (increases)
Find the new equilibrium point (E2)
Price has increased to PE2 and Quantity has increased to QE2.
at this point we can say for certain that
Price has increased
Quantity has increased
But, now Supply Increases (shifts right) to S2
Supply Shifts Right (increases) to S2
Find the new equilibrium point (E3)
Price decreases to PE3
Quantity Increases to QE3
Price originally increased to PE2
but now decreases to PE3, so price is (Uncertain)
Quantity has definitely increased to QE3
and finally, Supply Increases again to S3
Supply Shifts right (increases) to S3
New equilibrium point is at E4
Price decreases to PE4
Quantity Increases to QE4
Price is Uncertain
From the Demand & Supply Cheat Sheet here
Understand that you can either memorise these demand and supply shifts (not suggested) as they will not change.
So, If Demand increases and supply increases,
then Price will be uncertain and quantity will increase.
This happens no matter how you draw the curves, close or far apart.
I suggest drawing the graphs as you read the questions, then look for the equilibrium points.
How does the AP exam test these questions.
1995 AP Exam
Answer - E
2008 AP Exam
Answer - D
Government increases tax - supply decreases
People commute longer distances - demand for gas increases
Monday, September 11, 2017
Price Floors & Price Ceilings
Floors are High !
Say it again, Floors are High !
One more time, Floors are High !
A price floor is the lowest price that a supplier can charge for its good.
The price floor above is at $5, which mean that the $5 is the minimum price that the supplier can charge for its good. Governments often interfere in the market by passing laws that require producers (suppliers) to charge minimum prices. This price protects the suppliers in that no business can now charge less than the minimum price.
If a business decides to sell its good for less than the $5, the business owner might be fined or sent to jail.
Jacob Meged was a tailor of Polish descent who had a tailor shop at 138 Griffiths Street in Jersey City. He had a wife and four children and he needed money to feed his family. Other tailors were charging 40 cents, but he wanted to get more business, so he put a sign in his shop window advertising that he would press suits for 35 cents. After all, this was America where you were accustomed to being free to charge what you want. Beating the competition and being entrepreneurial was the American way, and he would be happy to press suits for 35 cents. Unfortunately, Jacob didn’t get more business and instead, he was arrested.J. Raymon Tiffany, Special Assistant Attorney General in charge of enforcing NRA codes in New Jersey took responsibility for prosecuting the tailor. When Jacob Meged was read the charges, he told Judge Kinkead that he was only vaguely aware of the existence of a code, but he pled guilty to the charge that he had violated the New Jersey State Recovery Act. Mr. Tiffany asked the court to impose a sentence stiff enough to warn other code violators that the law had teeth in it.
On Friday, April 20, 1934, Judge Robert V. Kinkead sentenced Jacob Meged to 30 days in the county jail, and he was ordered to pay a $100 fine. At 40 cents a suit, Meged would have to press 250 suits to cover his fine. That would be $100 he couldn’t use to feed his family, and in addition to this, he would lose a month’s earnings.
As The New York Times put it, “He believed that the codes were designed to help the ‘little fellow’ and could not believe that by charging 35 cents instead of 40 cents to press a suit would put him behind bars. In court yesterday he stood as if in a trance when sentence was pronounced. He hoped that it was a joke.”
A price floor below the equilibrium point (market clearing price) is NOT an effective or binding price floor.
If the minimum price (price floor) is set below the equilibrium market clearing point it will have no effect as the market has already cleared.
Jung Sub: I don't get it.
Mr. Waugh: Picture this,, at the $3 price Jung Sub buys all the jars of pinto beans that I'm selling.
I'm happy and Jung Sub is happy. The market has cleared.
Then a government employee walks in the room and says that we can't sell beans for less than $1 per jar. The $1 minimum required price had no effect on the market (IT WASN'T EFFECTIVE), IT MADE NO DIFFERENCE.
Tuesday, June 20, 2017
Friday, June 9, 2017
2017 AP Macroeconomics FRQ #3
(A) Draw a CLG of the PPC, with consumer goods on the horizontal axis and capital goods on the vertical axis. Indicate a point on your graph, labeled X, that represents full employment and a possible combination of goods produced.
PPC Cheat Sheet here.
(B) Assume that there is an increase in the country's national savings. Draw a CLG of the loanable funds market, showing the change in the real interest rate from the increase in savings.
Fiscal Policy Cheat Sheet here.
Understand that if savings is increasing then the supply of loanable funds is increasing.
If the supply of loanable funds is increasing then the RIR, real interest rate is falling.
(C) On the same graph in part (A), show another point, labeled Z, that represents full employed and a new combination of consumer goods and capital goods consistent with the increase in the nations increased savings.
Higher rate of savings implies a higher rate of capital investment which will lead to more future growth.
(D)Referring to your answer in part (C), will the long run aggregate supply curve shift right, left or remain the same.
The LRAS will increase in the long-run as savings increase, consumption and investment will increase. Investment will increase in capital goods and therefore future growth can be expected with a shifting rightward of the LRAS curve.
(A) Draw a CLG of the money market and show the effect of the reduced holdings of money on the equilibrium nominal interest rate in the short-run.
Money Market = Monetary Policy
Reduced holdings of money = Demand for Money decreases
From the Monetary Policy cheat sheet here
|Demand for Money falls, the Nominal Interest Rate (NIR) falls|
The opportunity cost of holding cash has fallen.
(B) Based on the changes in the interest rate in part (A), what will happen to each of the following in the short-run?
(i) Prices of previously issued Bonds. ((Bond Prices will Increase)
MR. Waugh - If interest rates are falling then we must assume that the interest rates of previous bonds must be higher.
Jung Sub - What does that mean, Mr. Waugh?
Mr. Waugh - Well Jung Sub, each bond has an amount of interest that it pays to the owner of the bond every year. It could pay 5% of the face value to the owner every year. Bond holders are rational people. If the banks are only paying 1% to borrow your money a bond holder would be making a profit by having a bond paying 5%.
So, if the nominal interest rate falls to 1%, then the price of a bond paying 5% will increase as it is now a better value than bonds created and sold today with a yield rate of 1%.
Is that clear Jung Sub?
Jung Sub - Not really Mr. Waugh, but I think we should move on.
|Jung Sub's face when I start talking about Bonds.|
(ii) The price level and real income.
Cause and effect - If the nominal interest rate falls then consumption increases which drives up AD and therefore the PL and causes the RGDP to increase which implies that real income (Y) increases also.
Answer - PL and Y (incomes) increase
(C) With a constant money supply, based on your answer in part (B)(ii), will the velocity of money increase, decrease, remain unchanged or will it be indeterminate?
Velocity of money is the rate that money exchanges for goods and services. If incomes are increasing we would expect that the velocity of money would increase.
AD is increasing along with RGDP and (Y) incomes so people are spending money faster than before. Velocity has increased.
(D) If the FED (central bank) wishes to reverse the changes in the interest rate identified in part (A), what open market operation (OMO) would it use?
If interest rates are falling (part A), then the FED would sell bonds, reducing the money supply and increasing the Nominal Interest Rate.