On the basis of the theoretical and empirical evidence available, indicate what overall conclusion can be reached

Question:

On the basis of the theoretical and empirical evidence available, indicate what overall conclusion can be reached on whether a flexible or a fixed system is preferred.
Exchange Rate
The value of one currency for the purpose of conversion to another. Exchange Rate means on any day, for purposes of determining the Dollar Equivalent of any currency other than Dollars, the rate at which such currency may be exchanged into Dollars...