Some people tip to bignote themselves, tossers making themselves out to be magnanimous, but I suspect that most people who tip do so because they confuse the staff's expectation with their obligation. In some cases people who tip are buying pleasantness, perhaps a little effusiveness, and in the US and Europe that has reached the point where people tip to avoid confrontation and abuse.

In my column in The Herald today I explore the proliferation of the glass of coloured water next to cafe cash registers. They're all primed with coins so you get the general idea, but I cannot see why anyone would, or why I should, give a gift of money to someone who is paid by their employer to carry a cup of coffee or a meal to my table. And certainly I don't want fawning waiters hovering by my elbow to top up my wine glass in the hope of a tip.

By the same token, why do many people tell a taxi driver to keep the change when they don't tell the butcher to keep the change? We pay the taxi driver to drive us to a destination and some seem to believe we should pay the driver extra when he does so! Or is it that taxi drivers, like waiters, are somehow converting their own expectation to the customer's obligation?

Does my refusal to tip mean that I'm a miserable bastard?