问题如下：
All else equal, which of the following was not a factor to increase the government deficit?
选项：
A.an increase in the excess of private saving over private investment.
B.an increase in net export.
C.a increase in trade deficit
解释：
B is correct.
The fiscal balance equation is given as: (G-T)=(S-I)-(X-M), An increase in government deficit (G-T) is a combination of increase in private saving over private investing (S-I) and a decrease of trade deficit or net export (X-M).
考点：Relationship between Income Approch and Expenditure Approach
解析：
财政平衡方程为:(G-T)=(S-I)-(X-M)，政府赤字(G-T)的增加的同时，私人储蓄增加超过私人投资(S-I)，或者贸易赤字或净出口(X-M)减少，所以AC选项不入选，B选项入选。
X-M<0,then trade deficit.trade deficit increases,thenX-M的数值变小(for example,-1变成-2，then-（X-M）从+1变为+2），then G-T变大
这样理解对不对？
