hi, Fabrizio,
thank you for your suggestion. we have thought about considering the number of co-authors when measuring the contribution of an author, we also understand that authors in different fields (different journals) have different pactice and tradition
of number of co-author. we have to run more experiements and get people's feedback first.
in the long run, we want to open up our meta data so that different people can measure our entities (author, paper, organization) differently according to their preference.
thanks.
-xin