NO.PZ2016010802000095
问题如下：
Because of a sharp decline in real estate values, the household sector has increased the fraction of disposable income that it saves. If output and investment spending remain unchanged, which of the following is most likely?
选项：
A.A decrease in the government deficit.
B.A decrease in net exports and increased capital inflow.
C.An increase in net exports and increased capital outflow.
解释：
C is correct.
The fundamental relationship among saving, investment, the fiscal balance, and the trade balance is S = I + (G – T) + (X – M). Given the levels of output and investment spending, an increase in saving (reduction in consumption) must be offset by either an increase in the fiscal deficit or an increase in net exports. Increasing the fiscal deficit is not one of the choices, so an increase in net exports and corresponding increase in net capital outflows (increased lending to foreigners and/or increased purchases of assets from foreigners) is the correct response.
考点：
解析： 一国GDP可以通过支出法表示 Y=C+I+G+X-M，也可以通过收入法表示 Y=C+S+T ，讲上述两者联立，可得：S=I+(G-T)+(X-M)
依据上式，净出口的增加可以导致储蓄S的增加，所以C选项入选B不入选。
财政赤字增加而非减少对应S的增加，所以A不入选。
- the household sector has increased the fraction of disposable income that it saves：这句话我的理解是增加了储蓄金中的可支配收入，说明存的钱花出去了？看不懂
- 这个解释：https://class.pzacademy.com/qa/109842
说Y是output不变，后面为什么又说根据题目 X-M 不变了？到底是哪个不变
