 This is a retrospective change (as VA invests more "after" poor returns), so while it alters the measured IRR it doesn’t generate more wealth for the investor.The study claims to demonstrate mathematically that VA is an inefficient investment strategy since the same outturns can be generated using other strategies which require less total cash to be invested.In addition, compared to other strategies, VA requires more active management, and a large “side fund” of cash or liquid assets which can be used to make the periodic investments required by VA.