Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We compare the long run reaction to anticipated and surprise information announcements using stock splits. Although there is underreaction in both cases, anticipated splits are treated differently to those that are unforeseen. After anticipated splits, cumulative abnormal returns peak at one-and-a-half times the level observed after unanticipated splits although the time taken for the announcement to be absorbed into prices is the same. We explain the difference in underreaction by the degree to which split announcements are believed and hence invested in. The favorable signal conveyed in forecast splits is more credible owing to their better pre-split performance, resulting in a far more pronounced underreaction effect.