In their paper "Behavioural Bias and Conflicts of Interest in Analyst Stock Recommendations," Journal of Business Finance and Accounting, authors Mokoaleli-Mokoteli, Taffler, and Agarwal tests whether sell-side analysts are prone to behavioral errors when making stock recommendations, as well as the impact of their investment banking relationships on judgment. The authors find that new buy recommendations on average have no investment value, whereas new sell recommendations do have value, although it takes time for the information to be assimilated by the market. They also find that new buy recommendations are distinguished from new sells both by the level of analyst optimism and conflicts of interest (no surprise there). Of interest, successful new buy recommendations are characterized by lower prior returns, while successful new sells do not differ from their unsuccessful counterparts in terms of these measures.

Interesting research, and somewhat intuitive - or at least it should be. New buy recommendations involve selling, and sell recommendations involve selling, ......., just a different kind.