This report on The Independent is downright bizarre.

Tipping practices in the USA are very different to those in the rest of the world. In the USA a tip of less than 15% is considered to be mean, and 25% is not unusual; whenever Sheryl returns to Munich from a visit to Chicago she has to relearn to tip the 10% that more is more usual in Europe. In America tips are expected for virtually all transactions, whereas in Europe people would not normally tip in a café or the like.

The main reason for the difference is that waiters, baristas and bar staff are typically not paid a proper wage in America, and need the tips to survive, whereas in Europe they get a livable wage. Americans are therefore used to tipping for everything.

Now, apparently since the pandemic, customers in the USA are being prompted to leave a tip at supermarkets when using the self-checkout, and customers are quite rightly refusing; they are questioning to whom the tip is going, and for what service they are tipping.

On restaurant bills (checks to you Yanks) tips are usually labelled as "service charges", and it is clear across the board that a tip is for service, so why do supermarkets feel it appropriate to receive a tip when no service was provided? Some people go so far as to suggest that the goods should be charged at a lower price at self-checkouts, since the customer is working for the supermarket during check-out.

I don't mind leaving a tip. I always give tips to taxi drivers, I always leave a tip when buying a doner kebab (even though there is no table service) and I always tip at restaurants, but I never feel obliged (obligated, in American) to tip. I do, however, have a firm rule: if I am leaving no tip, or a low tip, I must explain why (slow service, badly prepared food, or whatever), otherwise how can they improve? If we are regular customers of an establishment, we often tip over the odds, which ensures that we can always get a table, get good service and quality food (some of our neighbours do not understand why we often get a free second bottle of wine at our local sushi restaurant; it is because we tip them well).

Many years ago I used to work in the Holborn area of London, and was often short of time to get my train home from Charing Cross (too little time to take the tube train), so I would often get a taxi. Taxi drivers are notorious for their tricks to boost the fare, by taking a longer route, so I developed the trick of getting out enough money to cover the fare plus a fair tip, and shaking it noisily (only works if at least some of it is change) during the drive. This made it clear that any unnecessary diversions or delays were going to be at the expense of their tip. This technique worked amazingly well.