If you go to dinner wit 6 people or more, you’re in for an interesting lesson in utility, economics, and social convention. Here are some random thoughts:

Some people at group dinners are always takers while others are always givers. If you don’t drink much wine, you’re a giver. Because the check is pretty much always divided equally and wine is often one of the biggest expenses. Also, if you’re not a big eater, then you are a giver. And, if you often pass on dessert, then you’re definitely a giver.

Givers subsidize takers.

And what about the etiquette of ordering something expensive? I was out with 5 other people at a technology conference when one of the people (a former MySpace Europe executive) ordered a bottle of champagne. Not being much of a drinker, I had a few sips and gave the rest of my glass to the guy that ordered it. None of us thought much about it and when the check came, the guy calmly collected all our credit cards and gave them to the waiter. Not until after they were all charged did he disclose that he had ordered a $3000 bottle of champagne ($600/person). One of the people who was with us started crying.

And collecting money is always interesting. There are some friends that when I collect money, I’m somehow down an additional $50. there are other friends where I am somehow up and additional $50. (I prefer hanging with the latter). this is especially true when people leave early. Some people overpay and others underpay.

I was at a group dinner recently with Mark Pincus (CEO of Zynga). Mark had to leave early and left $100 (the dinner came out to $60 … I still owe Mark the extra $40). Mark is a good example of a giver. This week I was at another dinner when another CEO (who will remain nameless) had to leave early. He left $17 (why seventeen??) and the dinner came out to about $50/person (we won’t be inviting that guy to dinner again).