I don't know if the authors of this paper are members in this mailing list, but, in any case, I recommend this very well done study http://www0.cs.ucl.ac.uk/staff/l.capra/publications/icwsm13.pdf It talks about the effect of the mapping party (made in the city of London) in openstreet Improve map
In summary: - the mapping party map improve the data of OpenStreetMap and create enthusiasm - the users already active have a surge in the activity to inserting data - the users with a long experience don't insert data (but it 's thought that the problem is because they are committed in the organization) - the new people involved during the mapping party, in most cases, lose the interest to continue to inserting data _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk