问题如下：
In an equilibrium economy, if there is an increase in aggregate demand in the short run, the least likely effect is
选项：
A.the price level in the market will not be affected.
B.actual GDP is larger than potential GDP.
C.working hours of labors is increasing.
解释：
A is correct. Due to a short-run increase in aggregate demand, the equilibrium GDP level is larger than full-employment GDP. Labors will work overtime. The price level in the market will increase.
考点：总需求
解析：
由于总需求的短期增长，此时，短期需求曲线向右上平移，与供给曲线产生的新的交点均衡GDP有着更高的纵坐标和更大的横坐标，这代表均衡GDP水平大于充分就业GDP水平，并且市场上的价格水平将会提高。所以B选项不入选，A选项入选。
总需求短期增长，为了暂时提高产能，工人可能会加班。所以C选项不入选。
请问为什么市场上的价格水平会提高呢，潜在GDP是实际GDP的一个估计吗，谢谢
