Voting economy: balancing credits properly

Question

Many websites today (including stackoverflow) and games allow people to perform voting, give feedback, enable additional features etc, according to a score: eg. reputation, or MMORPG credits.

As a programmer that will probably need to implement a community based website in the near future, I am interested in knowing about the existence of basic algorithms and decisions to be made so that everything is balanced. For example, the fact that one vote up grants 10 reputations and one down grants -2 was arbitrary or properly weighted ? How to decide the price of a given item and the rewards in a MMORPG, so that everything is balanced? I guess that WoW designers relied on their experience, but I am also sure that this experience can be found somewhere written down. Although this is a social problem, the pricing of a given feature and the reward for a given task are technical/mathematical ones, as you need to give a value to each feature according to some mathematical criteria (although not easy to devise, I guess)

Of course, this question could bring us far in terms of theory of economics, but I am sort of hoping that there are well defined and known simplified patterns and rules for this issue. I just don't know the keywords to query for.

Answer 1

Probably the most important thing to point out here is that this is a social problem not a technical one.

By that I mean that you could use the exact same system as SO on an MMORPG and it would flop or have really undesirable side effects. Whether a system works or not depends on the community you drop it into and the intended purpose. It can also depend on some luck whether people latch onto it or not. You may get early negative behaviour that sets the tone for future negativity and discourages positive involvement. Or it could go completely the other way.

There is no magic formula that made the vote/rep weighting what it is on SO other than long discussions about how to encourage certain behaviour and then some testing and fine-tuning. For example, a downvote costs 1 rep and is -2 rep to the recipient. The guiding principle was that downvotes should cost. After that, it was trial by error.

You might want to read The Value of Downvoting, or, How Hacker News Gets It Wrong and Vote Fraud for some of Jeff's and Joel's thoughts on that subject. Joel's Tech Talk on Stackoverflow at Google is also enlightening.

Answer 2

Voting is actually a very difficult problem. There are so many models of voting, and they all produce different results. For example, choosing your one favorite candidate versus ranking candidates produces a different result. Choosing your LEAST favorite candidate produces a different result. Organizing choices into good/bad produces different results.

Balancing then becomes something that can be done by asking the community. It's very difficult to balance games of that magnitude, simply because even your most exhaustive tests wont cover all of the cases. Having a properly established forum where users can give their opinions as well as having testers who watch out for balancing issues is probably the best way to go.

Oh, and if you want an abstract about the voting problem I mentioned, it's here:

http://www.cs.rochester.edu/~lane/computational-politics.html