A.
The openness index helps to give a sense of how important trade is to an economy.
B.
It is possible for an openness index to be greater than 100 percent.
C.
A country that exported $20 billion, imported $30 billion, and had GDP of $100 billion would have an index of openness of 0.5 or 50 percent.
D.
Smaller countries tend to have lower openness measures than large countries.