A United Nations helicopter has been buzzing nonstop for days over Haiti, as the U.N. starts to draw down its personnel in Port-au-Prince, evacuating 14 people at a time in chopper rides. Many embassies and international aid organizations — includin

This article is part of our special section on the DealBook Summit that included business and policy leaders from around the world. Dario Amodei, the chief executive of the A.I. company Anthropic, puts his between 10 and 25 percent. Lina Khan, the c