The Value of Research

We estimate the value added by sell-side equity research analysts and explore the links between analyst research, informational efficiency, and asset prices. We identify the value of research from exogenous changes in analyst coverage. On announcement that a stock has lost all coverage, share prices fall by around 110 basis points or $8.4 million on average. The share price reaction is attenuated the more analysts continue to cover the stock, suggesting that there are diminishing returns to coverage at the margin. The adverse effect of coverage terminations is proportional to the analyst's reputation and experience and to the size of the broker's retail sales force. Exogenous reductions in coverage are followed by: less efficient pricing and lower liquidity; greater earnings surprises and more volatile trading around subsequent earnings announcements; increases in required returns; and reduced return volatility. Simulations suggest investors can trade profitably on the volatility changes. Finally, retail investors sell and large institutional investors buy around coverage terminations, suggesting that different investor clienteles have different demands for analyst research.