Much is known- or speculated- about how managers select securities and even countries for their portfolios.  But how important is the timing of those selections?  The authors say, "Plenty!

Performance Evaluation of Tactical Asset Allocation
Thomas Goodwin, Ph.D., Frank Russell Company;
Andrew Turner, Ph.D., Frank Russell Company;
Jon Christopherson, Ph.D., Frank Russell Company;
and Wayne E. Ferson, Ph.D., University of Washington