The answer is simple: Most economic ideas are public goods that cannot be patented or otherwise owned by their inventors. Just because most economists are not rich does not mean that they have not made many people richer.
怀疑派可能会问，“如果经济学家那么聪明，为何他们不是最富有的人？”答案很简单：大部分经济思想是公共品，不能申请专利还或者归发明者所有。大部分经济学家并不富有不意味着他们没有让许多人变得富有。