The tipping decision has to be divorced from the itself. You cannot give a tip until after the driver gives you your star raiding. The strong social norm, of course, is you do it. When we did the tipping and the ap, it's roughly ten to 15 % of trips are tipped.
Economist John List of the University of Chicago talks about his book, The Voltage Effect, with EconTalk host Russ Roberts. He discusses what determines scalability and argues that the only good ideas that count are those that scale. Along the way, he draws on his experiences as chief economist of Uber and Lyft to peer inside the black box of ride sharing.