I'd suggest that income is not a particularly significant factor in whether or not people participate in the Wikimedia movement, particularly as editors. Infrastructure including internet access, education, and availability of technology are far more significant.
These are all abundantly available in Europe, where we have probably the highest concentration of editors per capita (with the possible exception of the US).
In fact, I can't help wondering how a discussion of a European basic minimum income really comes across to our colleagues who live in countries where daily wages are the equivalent of the cost of a cup of coffee and a pastry in most of Europe, North America, and other "wealthy" countries. It's bothering me, and I live in one of those well to do countries.
Risker