Percentage Potshots

[steepholm]

Over the years, I've had a few recurrent fights in situations where I wanted to use raw values rather than percentages, but was stared as as if I was crazy. Yes, I know that sounds boring, but please bear with me.

Situation 1: Tipping a waiter. As you know, the standard practice is that you tip the waiter a percentage of the bill - let's say 10%. But it's always seemed to me that this unfairly discriminates against waiters who work in cheap restaurants. They're basically doing the same job as the waiters in posh restaurants, but a) they're probably getting a lower basic wage anyway, so b) by tipping them a percentage of your lower bill you are diddling them twice over. Surely it would be fairer to decide what amount constitutes a reasonable tip, adjust it a bit depending on whether the service is good or bad, and leave them that. I used to argue this point quite regularly, but gave up after a while because I found that I couldn't convince anyone that it made sense.

Situation 2: Deciding how many student papers need to be double-marked for the purposes of moderation. Standard practice in my place of work was for many years to prescribe a percentage of the scripts submitted - let's say 15%. Thus, you would end up double-marking a lot more scripts on a course with a high number of students than on a course with only a few. Every year, I would argue that for sampling purposes (at least of this type) what matters is the sample size, not the percentage of the population represented by the sample. (If you're not clear why this makes sense, there's a handy discussion here.) Every year, my colleagues would wait for me to calm down, and then take no notice.

Okay, perhaps in the grand scale of things neither of these things matters so much. Who cares about waiters or students, after all? (Actually, they're often the same people.) But twice in the last 24 hours I have heard people defending the large bonuses paid to bankers using the same kind of specious argument. In short, it goes like this: "X makes his living investing large sums of other people's money. If he is successful and his deals earn the bank a profit of $5,000,000 then it's only fair that he should be rewarded with a percentage of that profit." Not, note, rewarded with a few thousand extra in his pay packet. Not even with a percentage of his basic salary, but a percentage of the profit he has "earned". In other words, it's the posh waiter argument all over again, but with a posh waiter who serves platefuls of diamonds and gold bullion rather than beef wellington with grilled asparagus.

Do the banker apologists actually believe what they're arguing, I wonder? It would take only a very basic understanding of maths and statistics (which is all I have, if that) to see that their argument is tendentious at best. And yet - I remember the incomprehension of my colleagues; I think of the disbelieving faces of my dining companions of yore. These weren't stupid people in the ordinary way. And after all, that is the way we tip waiters, in the Square Mile as elsewhere. So, maybe they really do think it's a good argument - because they desperately want it to be one, and because let's face it, on the evidence of the last couple of years they aren't much cop with numbers.

Comments

[diceytillerman.livejournal.com]

Because of being physically disabled, I often take taxis. Sometimes the distance is short -- shorter than most people would need a taxi for. I've decided a minimum amount of money that I feel is okay as a tip, and I never tip lower than that amount, even if that amount is 40% of the fare.

[heleninwales.livejournal.com]

With the waiters, I think it depends on whether you believe that expertise and experience should be rewarded or not. In one sense, a waiter at an inexpensive establishment is doing the same job as one at a posh place. On the other hand, the person serving complicated posh food needs to be more knowledgeable and have better communication skills in order to deal with the more demanding customers.

In practice (not that we eat out a lot and very rarely at anywhere that could remotely be described as "posh") I operate a system similar to diceytillerman, namely that there's a minimum tip below which I feel it's unreasonable to go, but I could also see that there would be a maximum tip I would be prepared to give, however expensive and complicated the food got.

Re the sampling of assignments, a straight percentage is not how it's done in several courses I've been involved with. Both the NVQ and OCN verifications systems require more moderation for new assessors and new courses compared to well-established courses with experienced assessors. There is also a formula for how many portfolios to sample, depending on group size. That means that you are sampling a higher percentage of students' work in very small classes, though obviously the number of portfolios examined with be smaller.

[emmaco.livejournal.com]

I understand the flat fee/exams examples, but the bankers generally say they need a % of their profit as an incentive to work hard. So if you take that as the motivation, then a % system makes sense, as the more profit you make the higher your reward. Of course, I still think it's obscene to make that much money...

As an aside, I hate tipping. It makes me feel like the lady of the manor dispensing largesse. I just want everyone to be paid fairly, and not worry about extra money for some people (I mean, beginner chefs aren't paid huge wages, but they aren't tipped. Same with people serving in shops etc).

[papersky.livejournal.com]

I tip a rounded-up 15% with a minimum tip of $2.50. This is because of what you're saying, and because when this struck me, $2.50 seemed like the smallest amount of money it was actually worth having -- it was a pound at the time.

The only thing that makes sense with the bankers is that the bonus is an incentive not to embezzle.

[veronica-milvus.livejournal.com]

I suppose people would say that the best front of house service happens in the most expensive restaurants, so you are tipping the best waiters more money than in Pizza Express, for example.