The nature of externalities means that financial firms do not care about the costs that they may create for others. Big and small firms can create a wide variety of externalities, and these have to be examined carefully and dispassionately – exactly as Stein is recommending.
外部性的性质决定了金融企业不会关心它们给其他人造成的成本。大企业和小企业可以造成各种各样的外部性，而这些外部性必须冷静仔细地予以考察——这也正是斯坦的建议。