We’ve written before about the often-cited Vanguard “Advisor’s Alpha” study. That research documents the data showing that a good financial advisor can add on average a full 3% in incremental return to a client’s investment portfolio annually. The study then breaks that 3% down into its component parts, showing that the biggest gains–a full 150 basis points–come from effective behavioral coaching that serves to prevent clients from engaging in detrimental investing behaviors (think buying high …