One explanation for why analysts revise their recommendations after earnings announcements is that share prices do
not fully react to information in earnings and analysts attempt to exploit this inefficiency. Prior research shows that, when
firms are sorted into deciles based on earnings surprises, firms in the decile with the largest positive earnings surprise
outperform firms in the decile with the largest negative earnings surprise.
5
Abarbanell and Bernard (1992) compare the
earnings announcement reaction of share prices and analysts and find that analysts' forecasts are more efficient in
incorporating the information contained in earnings. Abarbanell and Bernard's (1992) results suggest that analysts possess
skills that can help them identify mispricings. Accordingly, analysts may revise their recommendations because they can
process earnings information more efficiently. To the extent that analysts identify mispricings and communicate them to
clients, their revisions would be more concentrated after earnings announcements and exhibit a positive association with
the direction and level of earnings surprise.