The impact of tax policy uncertainty on forecasting

This study examines the impact of tax policy uncertainty (TPU) on analysts' forecasts and managers' interim estimates of effective tax rates (ETRs). We adopt a broad definition of TPU that encompasses both the legislative and regulatory processes and perform tests to validate a news-based measure of TPU consistent with our definition. We document that 1) analysts' implied ETR forecasts are less accurate and more disperse during periods of high TPU, 2) managers' ETR estimates are less accurate during periods of high TPU, and 3) the presence of relatively inaccurate management ETR estimates strengthens the effects of TPU on analysts' ETR forecasts. We further find that firm-level tax-related complexity exacerbates the effects of TPU on analysts' and managers' ETR predictions. Overall, our results are consistent with uncertainty surrounding tax policy impairing analysts' and managers' ability to assess and predict future tax-related fundamentals, thus imposing real costs on managers and market participants.