Monday, October 05, 2009
Gini coefficient of MMORPGs
The Gini coefficient is a measure of equality or inequality, used in economics. It can be used for example to describe how income is distributed in a population. If one person had all the income, and everybody else had nothing, the Gini coefficient would be 1, perfect inequality. If everybody earned exactly the same, the Gini coefficient would be 0, perfect equality. It is easy to see that neither of these extremes would be stable, if one guy had all the money, the others would hang him up the next tree and distribute his wealth, or he would have to pay others to protect him, also leading to wealth distribution. If everybody earned exactly the same, regardless of effort, there would be no incentice to excert any effort, which is why communism failed, although the Soviet communism was still far from a zero Gini coefficient.
So the Gini coefficient is interesting insofar as there is no easily visible optimum. Very poor countries usually have a high Gini index, around 0.6. Europe has a very low Gini index, 0.31 in 2005, while at the same time the USA had a Gini index of 0.47. Any measures that change the Gini coefficient of a country usually give rise to strong emotions and discussions. Just look at issues like Obama's health care plans (which would lower the Gini index of the USA) or the excesses of banker's pay (which raise the Gini index).
Applying that concept to MMORPGs isn't all that easy. In the real world your wealth and income is measured in monetary terms. In a MMORPG it is measured in the power level of your character. For example somebody in World of Warcraft at the gold cap, geared up in the best equipment money can buy, would still be "poorer" than a top raider. So as a first approximation we could define the "wealth" of a WoW character as the sum of the iLevels of his equipment. But that would still leave us unable to compare the Gini coefficient of World of Warcraft with that of another game, because while the principle would be the same, the exact way on how to calculate power and wealth of a character would be different.
Nevertheless, while we might not be able to actually calculate the Gini coefficient of MMORPGs, we sure can state some general trends. For example we can say that over the years the Gini index for World of Warcraft went down, that is WoW became more equal. The difference in power level between an average character at the level cap and a top raider diminished, as nowadays it is a lot easier to get epic gear even for a non-raider, which wasn't true in WoW 1.0. We can also say that in other MMORPGs the power difference between the most successful and the average is wider, thus they have a higher Gini coefficient.
Looking at equality has important design consequences for a game. Games that are not MMORPGs, but nevertheless have "PvP", whether that is chess or Counterstrike, have a Gini coefficient of or near zero. Right now a bunch of developers from Blizzard is extremely busy trying to get the Gini coefficient of Starcraft II as close to zero as they can. Because if the result of PvP depends on a mix of power of your character(s)/units and player skill, by balancing the power you get a PvP that depends only on player skill. It is easy to see that the Gini coefficient of MMORPGs never is zero, and even with measures like battleground brackets and pairing based on arena ratings, it is impossible to get MMORPG PvP to be solely based on player skill.
Even for PvE the Gini coefficient is important. A game with a high Gini coefficient is like a third-world country with a ruling elite and lots of poor. That suits the elite just fine, but is obviously not so pleasant for the poor. And unlike the real world poor, the virtual world poor can always just leave and stop playing, which isn't good for the earnings of the game company. World of Warcraft lowering its Gini index and making players more equal is a direct consequence of such a consideration, of pleasing the average player to the detriment of a small elite. Nevertheless you wouldn't want to go too far, because if everybody is perfectly equal, then there is no game any more in gathering better equipment and raising your power level. Just like in the real world it isn't obvious where exactly the optimum lies, and any changes lead to heated discussion.