Economic models
a. assume that all factors in the model change at the same time.
b. include every detail found in the real world.
c. are not tested using real-world data.
d. can be used to explain or predict economic phenomena.

Assume that the following conditions exist: a. all banks are fully loaned up- there are no excess reserves, and desired excess reserves are always zero. b. the money multiplier is 5 .     c. the planned investment schedule is such that at a 4 percent rate of interest, investment =$1450 billion. at 5 percent, investment is $1420 billion. d. the investment multiplier is 3 . e.. the initial equilibrium level of real gdp is $12 trillion. f. the equilibrium rate of interest is 4 percent now the fed engages in contractionary monetary policy. it sells $1 billion worth of bonds, which reduces the money supply, which in turn raises the market rate of interest by 1 percentage point. calculate the decrease in money supply after fed's sale of bonds: $nothing billion.

In each of the following, what happens to the unemployment rate? does the unemployment rate give an accurate impression of what’s happening in the labor market? a. esther lost her job and begins looking for a new one. b.sam, a steelworker who has been out of work since his mill closed last year, becomes discouraged and gives up looking for work. c.dan, the sole earner in his family of 5, just lost his $90,000 job as a research scientist. immediately, he takes a part-time job at starbucks until he can find another job in his field.

The owner of firewood to go is considering buying a hydraulic wood splitter which sells for $50,000. he figures it will cost an additional $100 per cord to purchase and split wood with this machine, while he can sell each cord of split wood for $125. if, for this machine, design capacity is 50 cords per day, effective capacity is 40 cords per day, and actual output is expected to be 32 cords per day, what would be its efficiency?