[raldi]

> Is a 20% tip the norm for cabs?

Not historically. It used to be 10% or 15%. But then they put a screen in the back of the cab whose software says, "How much would you like to tip? [20%] [25%] [30%]" and then in a less enticing spot, "[Other]".

The power of evil, manipulative UI design is being used to make riders think that 25% is the typical taxi tip, and in a short amount of time, they'll have managed to use this fake-it-till-ya-make-it strategy to turn that lie into the truth.