An Analysis of Brokers' and Analysts' Unpublished Forecasts of UK Stock Returns
研究了35家英国股票经纪人和一家大型投资机构内部分析师对4000多只股票回报的未公开预测，发现预测有一定准确性，但信息在一个月内被市场消化，不过基于预测的交易仍能带来超额收益。
ABSTRACT This paper describes an empirical study of over 4000 specific share return forecasts made by 35 UK stockbrokers and by the internal analysts of a large UK investment institution. A comparison of forecast and realised returns reveals a small but potentially useful degree of forecasting ability. A large part of the information content of the forecasts, however, appears to be discounted in the market place within the first month. Nevertheless, an analysis of some 3000 transactions motivated by, and executed at the time of, the forecasts shows that the apparent predictive ability of the recommendations could be translated into superior performance by the fund's investment managers. Differences in forecasting ability between brokers do not appear to persist over time, but predictive accuracy can be improved by pooling simultaneous forecasts from different sources.