NO.PZ201512020800000403
问题如下：
3. Based upon Statement 1, over the requested forecast horizon, the factor that will most likely drive stock market performance is the percentage change in:
选项：
A.GDP.
B.the earnings to GDP ratio.
C.the price-to-earnings ratio.
解释：
A is correct.
In the long run, the growth rate of GDP is the most important driver of stock market performance. Therefore, the associate economist should focus on the drivers of long-run potential GDP growth. The ratio of earnings to GDP cannot increase indefinitely since that would imply that profit would eventually absorb all of GDP. This ratio cannot shrink forever either since unprofitable companies will go out of business. Thus, the annualized growth rate of the earnings to GDP ratio must be approximately zero over long time horizons, and this ratio should not be a dominant factor in forecasting long-term stock market performance. Similarly, the price-to-earnings ratio cannot grow or contract at a finite rate forever because investors will not pay an excessive price for each dollar of earnings, nor will they give away earnings for free. Therefore the rate of change in the price-to-earnings ratio must be approximately zero over long time horizons and should not be a dominant factor in the forecast of long-term stock market performance.
考点：股票市场和GDP之间的关系.
解析：依据公式% △ P=%△GDP+%△（E/GDP）+%△（P/E）
上述公式中，在长期earnings相对于GDP的增长率是趋近于0的，因为如果earnings的增长快于GDP的增长，那么总有一天，这家公司会吞并掉国家，这在现实中是不太可能发生的。如果earnings的增长一直低于GDP的增长，那么公司就将倒闭，这也是不太可能发生的。所以earnings的增长就应该等于GDP的增长
P/E的增长率也应该为0，因为P/E其实代表了人们对于市场的看法和估值，在长期来看，它是一个稳定不变的数值。
所以长期而言，股票市场价格的增长率就取决于GDP的增长率。
1.解析中的公式% △ P=%△GDP+%△（E/GDP）+%△（P/E）是从哪儿来的？跟讲义上的这串公式（下图）怎么有出入？
2.解析中最后一句话说长期来看，股票的增长率取决于GDP的增长率。这话成立的前提是outstanding shares deltaS为零吧？
