Both the all-inclusive definition of the term editor, and the systemic error, make the survival analysis as used a highly questionable method for analyzing the size of a community for recent years. By not realizing these inherent weaknesses the Wall Street Journal drew and published conclusions which are completely out of line with reality.
In wikistats we will continue to use editors with x+ edits per month as measure for ongoing activity. This measurement tells us that the number of editors that contribute monthly above a certain threshold has been relatively stable in the last 12 months, even more so for our core editor base, people that made 100 or more edits in a month.