工具变量的美妙之处在于它们让我们以新的视角看世界。

做出伟大工作的唯一方法就是热爱你所做的事。

无论情况如何，我总是尽力而为。

教育必须基于儿童的心理发展，而不是教育者的任意意志。

You’ve got to have models in your head. And you’ve got to array your experience—both vicarious and direct—on this latticework of models. You may have noticed students who just try to remember and pound back what is remembered. Well, they fail in school and in life. You’ve got to hang experience on a latticework of models in your mind.