Economics is, like medicine (and unlike, say, cosmology), a practical discipline. Its goal is to make the world a better place. This is particularly true of macroeconomics, which was invented by John Maynard Keynes in response to the Great Depression. The tests of this discipline are whether its adepts understand what might go wrong in the economy and how to put it right. When the financial crisis that hit in 2007 caught the profession almost completely unawares, it failed the first of these tests. It did better on the second. Nevertheless, it needs rebuilding.
經濟學是一門實用學科,與醫學一樣，而與（比如說）宇宙學不一樣。經濟學的目的是讓這個世界變得更美好。宏觀經濟學尤其如此，它由約翰?梅納德?凱恩斯(John Maynard Keynes)在對大蕭條(Great Depression)做出回應時所創。對這門學科的檢驗在于，宏觀經濟學專家是否了解經濟中哪里可能出問題以及如何糾正。2007年爆發的金融危機幾乎讓該學科完全始料不及，第一次檢驗不及格。第二次的成績好一些。但它需要重建。