昨天，美国联储主席伯南克在普林斯顿大学演讲。谈到经济学时，他说，这门学科相当复杂高深，特别擅长于解释过去的经济政策的错误。对于预测未来，作用没有那么大。（他曾经担任该校经济系主任。）

　　He said, "it is a highly sophisticated field of thought that is superb at explaining to policy makers precisely why the choices they made in the past were wrong. About the future, not so much.”