Tipping

This BBC article examines the US tipping culture. It raises some good points - like why should one add 10% or 20% to a bill, rather than a flat rate, when it is no harder to pour a $10 bottle of wine than a $100 one? Presumably this is a form of progressive redistribution - those who can afford the $100 wine can also afford to pay more to the lowly-paid bar staff.

It also suggests that tipping provides an incentive for good service. I'm unsure of this claim. It seems that the practice could in theory have that result, but if 10% (or whatever) becomes a standard - expected even for mediocre service - then it's no longer any incentive for extra effort beyond the call of duty, but merely what is expected. To have force as an incentive, it seems to me that the gratuity must be genuinely discretionary.