2009 高考經濟學 卷二 B & C 參考答案

本想早點完成卷二的參考答案，奈何工作繁多，又因本年的卷二題目較簡單直接，同學的爭議較少，擱下來了便遲遲未動筆。中文版將稍後發布，請同學耐心等待。

The answers provided hereunder offer only the correct approach to the questions, rather than the points that should be included in the examination for scoring marks. Readers should not simply evaluate their scores in the live examination on this basis (Readers in general may not know why it is so, although my students would definitely understand what I mean.)


Section B

Question 1

(a) False. The importation of workers from abroad will increase a country’s GDP only if there is no worker displacement or in the presence of worker displacement the productivity of imported workers are higher than the displaced workers. If the productivity of imported workers is lower than that of the displaced workers, the country’s GDP will fall. The first part of the statement is correct though, because GNP will decrease (increase) if the imported workers work for a period shorter than one year and their contribution to GDP, measured by marginal productivity, is smaller (larger) than the wage payments they earn in the economy, even in the absence of worker displacement.

(b) False. With an expectation-augmented Phillips curve, if the actual rate of inflation is lower than the expected rate, cyclical unemployment will be positive, i.e. cyclical unemployment coexists with inflation. Inflation, when fully anticipated, can coexist with natural unemployment.

(c) False. It would be generally more difficult to turn water into other goods and services at short notice without incurring loss, as in normal situations travelers would equip themselves with enough water and therefore water would not be easily marketable. (Given that money is a generally accepted medium of exchange and a better store of value, money is still the most liquid asset even in the Sahara Desert.)

(d) False. A fixed exchange rate system could not be maintained if the central bank does not have enough foreign exchange reserves to keep its currency at the target value. In terms of stability of exchange rate, under a fixed exchange rate system with a currency band, the exchange rate of a currency may fluctuate within the currency band while under a flexible exchange rate system the market exchange rate can be rather stable if there is no wild fluctuations in the demand for and supply of the currency, or if the effects of the fluctuations in the demand for and supply of the currency on the exchange rate offset each other.


Question 2

(a) Inclusive of the principal, the real interest rate is the price of goods today in terms of goods tomorrow.

(b) Inclusive of the principal, the nominal interest rate is the price of money today in terms of money tomorrow.

(c) Nominal interest rate is equal to the sum of the real interest rate and the anticipated inflation rate. The inflation rate is expected (or ex ante) because the actual inflation rate is not realized at the time when the nominal interest rate is determined.

(d) If we interpret money as a non-interest-bearing asset, the nominal interest rate, being the return on holding other interest-bearing assets, is the cost of holding money. The nominal interest rate in this case is equal to the interest differential between the return on other interest-bearing assets and money, and the nominal interest differential is equal to the real interest differential. In the case of money being an interest-bearing asset, the nominal interest differential is still equal to the real interest differential, and both can be interpreted as the cost of holding money.



Question 3

(a) In equilibrium, Y = C + I + G for a closed economy, and therefore Y − C − G = I. National saving (S = Y − C − G), representing the part of output not consumed by the households and the governments, would be equal to investment.

(b) Real investment is equated to national saving in a closed economy because both investment and saving are decisions related to real resources (investment referring to the accumulation of capital goods while saving referring to output not consumed by the households and the government).

(c)(i) In equilibrium, Y = C + I + G + NX for an open economy, and therefore Y − C − G − I = NX. (S − I) equals NX.

(ii) The excess of domestic investment over national saving would be financed by net imports (NX <>), which can be viewed a net capital inflow (recall the balance of payment condition of NX = −KFA).

(d) A high consumption country would tend to have a low level of national saving. Given the condition of (S − I) = NX and a certain level of I, it is more likely that S falls below I, resulting in a trade deficit (NX <>).




Section C

Question 4

(a) A liquidity trap means the situation where the interest rate reaches a sufficiently low level and the opportunity cost of holding money (the return on other interest-bearing assets) is so low that people would hold money (as an asset providing liquidity) rather than other interest-bearing assets, which are likely to incur capital loss to their holders. The money demand curve will be perfectly interest elastic (with a horizontal portion at the existing interest rate).

(b) Under a liquidity trap, an increase in income (Y) and therefore the transaction demand for money would be offset by a corresponding decrease in asset demand for money at the existing interest rate (or an infinitesimally small increase in the interest rate).

An increase in money supply by the central bank would not lead to a fall in interest rate because the newly printed money would be translated into money demanded for asset purpose at the going interest rate, therefore would not be able to stimulate output.

(c) When interest rate is used as the policy instrument, an increase in income (Y) and therefore the transaction demand for money, given a downward sloping money demand curve without the perfectly interest elastic portion, would have to be accompanied by a corresponding increase in money supply by the central bank so that the equilibrium interest rate remains at the target level.

(d) The central bank would be able to lower the interest rate, but given the perfectly interest-elastic money demand it will result in money market disequilibrium. Therefore, in the context of money market equilibrium central bank could not lower the interest rate. If a liquidity trap occurs at the zero lower bound of interest rate, the interest rate could not be lowered, irrespective of whether money market equilibrium is considered.



Question 5

(a)(i)
In country A, the opportunity cost of producing
1X = 2Y or 1.5Z ; 1Y = 0.5X or 0.75Z ; 1Z = 2/3X or 4/3Y

In country B, the opportunity cost of producing
1X = 2/3Y or 2Z ; 1Y = 1.5X or 3Z ; 1Z = 0.5X or 1/3Y

In country C, the opportunity cost of producing
1X = 0.625Y or 1.5Z ; 1Y = 1.6X or 2.4Z ; 1Z = 2/3X or 5/12Y

(ii)
Comparative advantage
Good X: country C ; Good Y: country A ; Good Z: country B


(b)
Total world production under autarky
Good X: 8 units ; Good Y: 6.5 units ; Good Z: 13.5 units

(c)
Total world production under complete specialization
Good X: 12 units ; Good Y: 6 units ; Good Z: 18 units

(d)(i)
Consumption for each country
Good X: 4 units ; Good Y: 2 units ; Good Z: 6 units

Both country A and B will gain (country A consumes the same quantity of Good Y but a larger quantity of Good X and Z, and country B consumes the same quantity of Good Y and Z but a larger quantity of Good X). Country C will lose (it consumes the same quantity of Good X and Z but a smaller quantity of Good Y).

(ii)
The winner(s) (A and/or B) has/have to compensate at least 0.8X to C (country C’s opportunity cost of producing 0.5Y = 0.8X).



Question 6

(由於此題包含符號，只能以圖片上載，同學按下圖片便能看得清楚。)