A few years ago in Manhattan, I had dinner at a pub with seven or eight New Yorkers. We ran up one bill, and our arithmetic was booze-impaired, so we guesstimated the tip.Mistake. As we trooped out onto the pavement, the waiter rushed out of the pub and hollered at us: "You guys! 15%?! What the hell?"So we returned and sheepishly bumped up his tip to 25%. For a South African, it was an odd experience - we're not used to our gratuity being furiously challenged.In major US cities, tipping well in sit-down restaurants is legally optional but culturally compulsory. In New York, the minimum restaurant wage is $7.25 (R103) an hour, which might net a waiter $1300 a month. To put that in perspective, the average rent for a one-bed apartment in New York is $3152 a month. But the vast majority of most waiters' income is in tips, which serve to make the job a viable career.Compare that to South Africa, where the minimum wage for restaurant workers is a miserable R14.15 an hour - roughly one-seventh of its New York equivalent - and yet our tipping norm is 10% for good service, more if you're feeling generous. Many South Africans don't tip at all, or shed some pocket change. In most restaurants, full-time waiters take home less than R5000 a month. That's not enough to build a life or raise a child.story_article_left1Our tipping culture is particularly miserly given that eating out in South Africa is, by global standards, unusually affordable for middle-class consumers. A meal at a mid-priced restaurant is often not much more expensive than cooking the same meal yourself at home with good ingredients - and that's not the case in most developed economies. Restaurant chains are effectively subsidised by extremely low staff input costs, with rock-bottom kitchen salaries the norm. High staff turnover is routine as a result.This doesn't mean the South African restaurant business is a cakewalk - particularly in these grim times. But its viability in South Africa is largely down to an oversupply of cheap labour.This partly explains the appetite among foreign restaurant chains to set up shop here. There is always a queue of jobseekers waiting to replace a cook or waiter fed up with earning a pittance.That imbalance sustains many other local industries, but consumers can't tip miners or farm labourers. The South African restaurant is an unusually porous boundary between two economic worlds. Its customers wield the power to ease, in a small but potentially significant way, the gruesome inequity of our society - by tipping at a level that is morally appropriate to the gap between their income and the waiter's income...