Recent scholarship has established that Berenson's secret agreements with Duveen resulted in substantial profits to himself, as much as 25% of the proceeds, making him a wealthy man. This clear conflict of interest has thrown into doubt many of his authentications for Duveen and a number of these have been shown, through careful examination, to have become more optimistic, therefore considerably more valuable, once he was working for Duveen. No systematic comparison has, as yet, been done, but a partial study of seventy works points to this possibility. (Meryle Secrest, "Being Bernard Berenson", 1979, Appendix, p. 399) The issue is still controversial.