On the Inequality of Contributions to Wikipedia

Wikipedia is one of the most successful examples of massive collaborative content development. However, many of the mechanisms and procedures that it uses are still unknown in detail. For instance, how equal (or unequal) are the contributions to it has been discussed in the last years, with no conclusive results. In this paper, we study exactly that aspect by using Lorenz curves and Gini coefficients, very well known instruments to economists. We analyze the trends in the inequality of distributions for the ten biggest language editions of Wikipedia, and their evolution over time. As a result, we have found large differences in the number of contributions by different authors (something also observed in free, open source software development), and a trend to stable patterns of inequality in the long run.