PDT 2/2 : Why has tipping increased?

[El Diablo]

Pyro,

"I'd always understood the traditional amount-to-tip-on as the meal itself"

Yes. People used to talk about "tax + tip" being a certain combined percentage applied to sale. Now most people talk about tip on top of the amount of the bill, which includes tax.

I think that's due to two things - laziness in math and some good work by the tip-receiving community in always talking about it like that, resulting in a couple extra percent coming their way.