Using time stamps of Standard & Poor's rating changes, we examine the timing of rating changes in an intraday setting. Our evidence shows that although most rating changes occur during trading hours, the proportion of downgrades announced after regular trading hours is higher than that of upgrades. In addition, unexpected after-hour downgrades are associated with more negative stock returns and lower trading volume in comparison to those announced during trading hours. We also find that Standard & Poor's is more likely to announce downgrades after hours when downgrades are released on busy days with many concurrent rating announcements, when they concern financial firms, and when they are unexpected. In addition, Egan-Jones Ratings (EJR), an investor-paid credit rating agency, demonstrates a similar tendency in announcing downgrades after trading hours. This is the first study to document systematic differences in the timing of credit rating changes announced before and after the market closes. Our findings suggest that Standard & Poor's announces downgrades after trading hours to better disseminate information, and thus have important policy implications.

Earnings non‐synchronicity reflects the extent to which firm‐specific factors determine a firm's earnings. Prior research suggests that high earnings non‐synchronicity impedes corporate outsiders' ability to process information. This study examines the impact of earnings non‐synchronicity on managers' decisions to provide earnings forecasts. We propose that high earnings non‐synchronicity motivates managers to issue earnings forecasts to reduce information asymmetry between managers and investors and to preempt costly information acquisition by outsiders. Consistently, we find a positive relation between earnings non‐synchronicity and managers' propensity to issue earnings forecasts, particularly long‐horizon forecasts. This positive relation is weaker when earnings are easier to predict based on the firm's earnings history and is stronger when the firm has higher institutional ownership and greater analyst following. We also find that the market's reaction to management forecasts increases with earnings non‐synchronicity. Overall, the evidence suggests that managers voluntarily provide earnings forecasts to alleviate the adverse consequences of earnings non‐synchronicity. These findings provide a more complete picture about the impact of earnings non‐synchronicity on a firm's information environment, and highlight the effect of the nature of information asymmetry on voluntary disclosures.