109 年 國立政治大學商學院碩士班共同科目《經濟學》

Suppose Ethan increases his working hours when obtaining higher hourly pay. Which of the following statement(s) is (are) correct?

(i) Leisure could be an inferior good to Ethan.
(ii) Leisure could be a normal good to Ethan.
(iii) Leisure could be a Giffen good to Ethan.

(A) (i) and (iii)
(B) (ii)
(C) (i) and (ii)
(D) (i), (ii), and (iii)

Which of the following statement(s) is (are) correct when a government imposes tax on a good?

(i) When supply is perfectly inelastic, imposing tax on consumers creates zero deadweight loss.
(ii) When demand is perfectly elastic, imposing tax makes the market price of the good unchanged.
(iii) When supply is perfectly elastic, and demand is perfectly inelastic, imposing tax makes the market equilibrium quantity unchanged.

(A) (i) and (iii)
(B) (ii)
(C) (i) and (ii)
(D) (i), (ii), and (iii)

Which of the following statement(s) is (are) correct?

(i) A monopoly firm can increase its revenue by raising the price when demand is perfectly inelastic.
(ii) When marginal cost is zero and demand is linear, a monopolistic competitive firm will produce at the midpoint of the demand curve.
(iii) A perfect competitive firm produces at the point that price elasticity of demand equals one.

(A) (i) and (iii)
(B) (ii)
(C) (i) and (ii)
(D) (i), (ii), and (iii)

Assume Ethan's preference on two goods, $X$ and $Y$, follows typical assumptions in Economics. His budget constraint is $2X+4Y=20$, and his optimal consumption bundle is $(2,4)$.

Which of the following consumption bundles is possible to give the same utility level to Ethan as $(2,4)$?

(A) $(3,7)$
(B) $(5,2.5)$
(C) $(0.5,4)$
(D) $(1,7)$

Town A has only three residents. They are deciding whether to spend \450$ to provide a public good. The public good will only be provided when all of three residents agree to do it. The value of the public good to each resident is:

🖼️【此處有附圖，請對照原卷】

Resident A: $i$
Resident B: $ii$
Resident C: $iii$

What is a possible bundle of $(i,ii,iii)$ that this public good will be provided?

(A) $(0,0,460)$
(B) $(100,150,130)$
(C) $(120,150,160)$
(D) $(140,140,140)$

When marginal cost exceeds average total cost,

(A) average fixed cost must be falling.
(B) average fixed cost must be rising.
(C) average total cost must be rising.
(D) average total cost is falling.

If a firm in a competitive market increases production and its marginal revenue remains positive, raising production will

(A) be profitable.
(B) cause the firm to incur losses.
(C) leave profit unchanged.
(D) It is impossible to tell from the information provided.

When a natural monopoly exists, it is

(A) always more cost effective for two or more private firms to produce the product.
(B) never more cost effective for two or more private firms to produce the product.
(C) always more cost effective for government owned firms to produce the product.
(D) never more cost effective for one firm to produce the product.

If identical products are sold by firms participating in a market, the market is

(i) perfectly competitive.
(ii) an oligopoly.
(iii) monopolistically competitive.

(A) (i) or (ii)
(B) (ii) or (iii)
(C) (i) or (iii)
(D) (i) only

A profit-maximizing firm in a monopolistically competitive market is characterized by which of the following?

(A) Revenue is always maximized along with profit.
(B) Average revenue exceeds marginal revenue.
(C) Marginal revenue exceeds average revenue.
(D) Average revenue is equal to marginal revenue.

Every year more and more purchases are made with credit cards on the Internet. Given this trend, all else equal, we would expect:

(A) the money demand curve to shift outward.
(B) the money demand curve to shift inward.
(C) a downward movement along a fixed money demand curve.
(D) an upward movement along a fixed money demand curve.

As a result of a decrease in the value of the dollar in relation to other currencies, American imports decrease and exports increase. Consequently, there is a(n):

(A) increase in short-run aggregate supply.
(B) decrease in the quantity of aggregate output supplied in the short run.
(C) increase in aggregate demand.
(D) decrease in the quantity of aggregate output demanded.

The money demand curve is:

(A) downward-sloping because the opportunity cost of holding money is inversely related to the interest rate.
(B) downward-sloping because the opportunity cost of holding money rises as the interest rate rises.
(C) downward-sloping because the opportunity cost of holding money rises as the interest rate falls.
(D) upward-sloping because the opportunity cost of holding money rises with the interest rate.

An example of the frictionally unemployed is a(n):

(A) autoworker who is temporarily laid off because of a decline in sales.
(B) geologist who is permanently laid off from an oil company due to a new technological advance.
(C) worker at a fast-food restaurant who quits work and attends college.
(D) real estate agent who leaves a job in Texas and searches for a similar, higher paying job in California.

Suppose that in year 1 an economy produces $100$ baseballs that sell for \3$each and$75$pizzas that sell for$$8$each. The next year, the economy produces$110$baseballs that sell for$$3.25$each and$80$pizzas that sell for$$9$ each.

Using year 1 as the base year, the growth rate of real GDP from year 1 to year 2 is:

(A) $10\%$.
(B) $7.8\%$.
(C) $19.7\%$.
(D) $8.8\%$.

Suppose the economy is in long-run equilibrium. Concerns about pollution cause the government to significantly restrict the production of electricity. At the same time, taxes fall. In the short-run

(A) real GDP will rise, and the price level might rise, fall, or stay the same.
(B) real GDP will fall, and the price level might rise, fall, or stay the same.
(C) the price level will rise, and real GDP might rise, fall, or stay the same.
(D) the price level will fall, and real GDP might rise, fall, or stay the same.

Critics of stabilization policy argue that

(A) "animal spirits" must be offset by active monetary policy.
(B) active monetary policy is necessary for steady economic growth.
(C) the lag problem ends up being a cause of economic fluctuations.
(D) active fiscal policy is required for steady economic growth.

Which of the following contains a list only of things that decrease when the budget deficit of the U.S. increases?

(A) U.S. net exports, U.S. domestic investment, U.S. net capital outflow
(B) U.S. supply of loanable funds, U.S. interest rates, U.S. domestic investment
(C) U.S. imports, U.S. interest rates, the real exchange rate of the dollar
(D) U.S. interest rates, the real exchange rate of the dollar, U.S. domestic investment

If purchasing power parity holds, then if the price of a basket of goods in the U.S. rose from \1{,}000$to$$1{,}200$and the price of the same basket in Poland rose from$6{,}400$Polish zloty to$8{,}000$ zloty, then

(A) the nominal exchange rate would be unchanged and the real exchange rate would appreciate.
(B) the U.S. dollar would appreciate and the real exchange rate would stay the same.
(C) the nominal exchange rate would be unchanged and the real exchange rate would depreciate.
(D) the U.S. dollar would depreciate and the real exchange rate would be unchanged.

Imagine the U.S. economy is in long-run equilibrium. Then suppose the value of the U.S. dollar decreases. At the same time, people in the U.S. revise their expectations so that the expected price level rises. We would expect that in the short-run

(A) real GDP will rise and the price level might rise, fall, or stay the same.
(B) real GDP will fall and the price level might rise, fall, or stay the same.
(C) the price level will rise, and real GDP might rise, fall, or stay the same.
(D) the price level will fall, and real GDP might rise, fall, or stay the same.

Assume a government imposes a tax on the market of good $A$. The total tax revenue is \500$, and the quantity demanded is$100$. Further, the demand is linear and has a slope of$-\frac{1}{5}$. The supply equation is$Q^S=2P$.

A. (4 points) What is the price that consumers pay after the tax?

B. (4 points) What is the demand equation?

C. (4 points) What is the size of the deadweight loss of the taxation?

D. (4 points) What is the tax burden of consumers?

E. (4 points) Additionally, assume the government imposes this tax to deal with externality efficiently. What is the size of the externality per output unit? Is this externality positive or negative?

Consider an endowment economy (an economy without production). The utility function of each consumer is $U=D_x^{1/2}D_y^{1/2}$, where $D_x$ and $D_y$ represent demand of $x$ and $y$ respectively. The endowment of $x$ is $20$ units and that of $y$ is $30$ units. Answer the following questions.

A. (5 points) Show that the utility function is homothetic.

B. (5 points) Derive the demand of $x$ relative to $y$ as a function of $p_x/p_y$, where $p$ represents price.

C. (5 points) Derive the equilibrium level of $p_x/p_y$.

D. (5 points) Suppose there is another economy, where consumers have the same utility function but both the endowment of $x$ and $y$ is $30$ units. Derive the equilibrium level of $p_x/p_y$ under free trade.

Given the following information: bank deposits $350$, currency-to-deposits ratio $0.20$, required reserve ratio $0.15$,

A. (15 points) Solve for the monetary base level, the level of bank reserves, and the money supply level in this economy.

B. (5 points) Suppose there is a sudden rise in the currency-to-deposits ratio, from the original level of $0.2$ to a new level of $0.4$. If everything else remains unchanged, find the level of monetary base needed to keep money supply fixed at the same level.

One example of how inflation discourages saving is the tax treatment of capital gains. Suppose that someone bought a parcel of land for \2{,}000$in 1980 when the price index equaled$100$. In 2018, the person sold the land for$$13{,}000$, and the price index equaled$500$. The tax rate on nominal gains was$20$ percent.

A. (5 points) Find the before-tax real rate of capital gains.

B. (5 points) Compute the taxes on the nominal gains in terms of 2018 prices.

C. (5 points) Compute the after-tax real value of the land in terms of 1980 prices.

D. (5 points) Find the after-tax real rate of capital gains.