This study brings together two related literatures on information risk and transaction costs to provide a comprehensive
analysis of price discovery around and after earnings announcements. Building on the existing literature we propose
two hypotheses. TheInformation Content hypothesis posits that public disclosure has a higher relative importance in firms
with higher information risk, and hence traders will react more strongly to the earnings surprises of firms with higher
information risk; however, this hypothesis predicts no effect of information risk on subsequent drift. The Transaction Cost
hypothesissuggests that as a market friction and a limit to arbitrage, transaction costs constrain the initial market reaction
and this leads to a positive association with post-earnings announcement returns.
Using data for US stocks between 1993 and 2007, we test the implications of these hypotheses in a unified framework across
two dimensions: the initial market reaction and the subsequent post announcement returns. First, we find that the earnings of
firms with higher levels of information risk contain morenewinformation for the market and induce higher initial market reactions
—this is the direct information risk effect. Second, higher information risk feeds into higher transaction costs, and such costs delay
the flow of information into stock prices and explain their higher, post-earnings announcement returns. Particularly, we show that
once transaction costs have been controlled for, the post-earnings announcement returns strategy does not earn abnormal risk-adjusted returns in the traditional four factor asset pricing model, even in the highest information risk quintile.
Therefore, our results unify the two related explanations for the post event price drift: information risk and transaction
costs. We demonstrate that information risk has two channels of effect on the price discovery around news announcements:
information content and the transaction costs effect. It suggests that while information risk is an important determinant of
the price discovery process, transaction costs capture parts of its impact in the markets. Overall, it highlights the importance
of firm level information environments in determining the market reaction to public disclosures.