Do Analysts Mind the GAAP? Evidence From the Tax Cuts and Jobs Act of 2017

This study examines the quality of analysts’ GAAP-based earnings forecasts. Ideally, addressing this question requires events that have an ex ante estimable earnings impact, and affect GAAP earnings but not street earnings. The deferred tax adjustment as a result of a 2017 tax law change meets these criteria. Focusing on the fourth quarter of 2017 (2017Q4), we find that analysts’ GAAP earnings forecasts and revisions fail to incorporate the vast majority of the deferred tax adjustment. We explore two potential explanations for this finding – task-specific complexity and lack of GAAP earnings forecasting effort. We find evidence consistent with the latter. Our final analyses consider two implications of our findings. First, despite analysts underreacting to the deferred tax adjustment, investors promptly impound the adjustment into stock prices at the legislative enactment date, indicating that analysts’ GAAP earnings forecasts are not a good proxy for investor expectations of GAAP earnings during our sample period. Second, analysts who best incorporate the adjustment into their 2017Q4 GAAP earnings forecasts issue more accurate GAAP earnings forecasts for subsequent quarters, indicating that our inferences extend beyond a single quarter and account. Collectively, these findings have implications for research that relies on analysts’ GAAP earnings forecasts to be of reasonable quality.