brad stone, andriana gid -- anr gidones. in a moment. . >>> uber and abnb has a combined value of $100 billon with a b, dollars. he writes about the upstarts, how uber, and the killer companies of the new silicone valleys are changing the world. >> great to have you. for the better or worse? >> there is plenty of criticism to lob at the companies, i don't think you can argue that the change has been anything but good for cities. i don't need rent-a-car anymore. not only for riders, people who want to drive for a living. the taxi market was, it is hard to get a medallion in new york or london. it has created a new line of work, for anybody who wants to work. lose their job, supplementing in college. maybe in-law apartment. a way to make money. there are excesses on both platforms, the companies cut corners, they were challenging regulatory regimes, the ceoos are aggressive, young tech folks, i believe it is for the better. >> both ceo's are aggressive, the uberguy, beyond aggressive. people hate this guy. this is me, saying t