Many theorists and decision-makers believe that decision-making flexibility should have some value.But this conjecture is not proved in a general framework of decision-making theory.This paper is to prove the conjecture.Through a review of literatures on flexibility,this paper draws out the essential properties of flexibility,i.e.range and speed.Further,this paper generally provides the formal definition of decision-making flexibility,builds a model of flexible decision-making,and points out the...