Carpooling question_?

This is an interesting, non-trivial problem, because what's "fair" is neither obvious nor unambiguous. The most obvious thing to do, which most people are likely to do, is to draw lots every morning as who is going to drive. Few are likely to object to that, and it's simple and flexible. But let's say that there is some set of people that can be expected to carpool over a lengthy time period, say a year, while who actually carpools on any given day could vary. Let's further say that the set of travelers insist on strict accounting of driving time and not left to chance. A good place to start would be to have a system of credits, such as every passenger paying the driver a "dollar" in credit, so that drivers accumulates credits while passengers spends it. The objective is that by the end of the year, everybody has a credit balance of zero or something close to it. Unfortunately, even something as simple as that has at least two different implementations based on different ideas of what's "fair".

1) All the passengers each pay the driver 1 credit. So, if the carpool has a lot of passengers, the driver stands to make a lot of credit.

2) The driver always makes just 1 credit, so that if the carpool has a lot of passengers, they each end up playing less.

In other words, there could be disputes over who gets to drive or to be a passenger, because what's advantageous depends on the size of the carpool and the system used. Let me think about this problem a bit more.

Edit: Okay, while recognizing that it's probably not possible to "logically determine" what is fair, because ultimately it's a subjective concept, we can propose that what seems most fair to most people is to draw lots every time a carpool is done. But instead of choosing randomly, we can tabulate the expectations of each carpool person to be the driver, which is 1/N, where N is the number of persons in the carpool, driver included. Then whoever drives on that day gets his running tab reduced by 1. On any given day, it's the person with the highest outstanding running tab that has to drive (ties can be broken with a flip of the coin or other such means). This means that the sum of all the running tabs is always 0, some will have positive and some will have negative running tabs. Even in the case where only one person shows up and drives, his expectation is 1, and yet his running tab will be reduced by 1, which makes it a wash and has no impact on others, as it shouldn't. In the long run, it should statistically match what happens if lots were drew every time. More importantly, it removes any incentive or purpose for members to try to "game the system", even when clear cut rules are in place that doesn't (essentially) depend on chance.

You can simply have a list of everyone who takes a carpool, and divide it by days.. say there are 6 people who need a car pool. Maybe 4 show up on monday, and 2 show up on wednesday etc. Make a list for those to know when it's their turn.

Best answer?

You need a whole lot more information than this. We don't know if you're talking about gas money or what. "deems it fair on who drives on a particular day" doesn't make any sense grammatically or logically.

Hmm, I think if this happens, there should be a vote-on-the-spot system. My two cents.

By the way, I was curious as to why you deleted your answer to one of my questions?