For those working in quantitative finance, this has been expected for a while. Now, there is some good solid research backing up this claim. The full paper is available here.
hundred individuals who hold a Ph.D. in economics, finance, or others
fields work for institutional money management companies. The gross
performance of domestic equity investment products managed by
individuals with a Ph.D. (Ph.D. products) is superior to the performance
of non-Ph.D. products matched by objective, size, and past performance
for one-year returns, Sharpe Ratios, alphas, information ratios, and the
manipulation-proof measure MPPM. Fees for Ph.D. products are lower than
those for non-Ph.D. products. Investment flows to Ph.D. products
substantially exceed the flows to the matched non-Ph.D. products.
Ph.D.s’ publications in leading economics and finance journals further
enhance the performance gap."