I examine whether earnings generated by changes in effective tax rates (the tax change component) persist and aid in forecasting future earnings. In addition, this study investigates to what extent investors incorporate the forecasting implications of the tax change component of earnings into stock prices. I find that there is a positive, significant association between the tax change component of earnings and future earnings. I use the interim reporting requirements of APB No. 28 (APB 1973) and FASB Interpretation No. 18 (FASB 1977) to further decompose the tax change component into an initial and a revised portion based on the first quarter estimate of the annual effective tax rates (ETR). I find that the initial tax change component is more persistent for future earnings than the revised tax change component. These results are consistent with my hypotheses that the initial and revised tax change components have differential persistence and forecasting implications, and dispute the broad notion advanced by prior literature that ETR-related earnings changes are transitory. Results from market tests indicate that the market underweights the forecasting implications of the tax change component and the mispricing appears to be driven by the transitory nature of the revised tax change component.

We examine whether public disclosures of tax reserves recently made available through Financial Interpretation No. 48 (FIN 48) reflect corporate tax shelter activities. Understanding this relation is important to corporate stakeholders and researchers keen to infer the aggressive nature of a firm's tax positions from its tax reserve accrual. Our study links public disclosures of tax reserves with mandatory private disclosures of tax shelter participation as made to the Internal Revenue Service's Office of Tax Shelter Analysis. We find strong, robust evidence that the tax reserve is positively associated with tax shelters, while other commonly used measures of tax avoidance are not. Based on out‐of‐sample tests, we also show that the reserve is a suitable summary measure for predicting tax shelters. The tax benefits of tax shelters are economically significant, accounting for up to 48% of the aggregate FIN 48 tax reserves in our sample.

This study uses insights from tax practitioners and tax authorities to define and develop an estimate of ex ante tax risk that is independent of common tax outcomes studied in prior literature. Validation tests confirm that our tax risk measure (i) represents the predictable and unpredictable uncertainty inherent in the three sources of tax risk (i.e., economic risk, tax law uncertainty, and inaccurate information processing) and (ii) is a construct different from tax avoidance, tax uncertainty, and general business risk. Using our tax risk measure, we address two research questions of interest to academics and practitioners. First, we examine the association between tax risk and long‐run tax avoidance and find a negative association between tax risk and future long‐run cash effective tax rates (ETRs). Second, we consider the extent to which unrecognized tax benefits (UTBs) reflect tax risk, tax avoidance, or financial reporting incentives and demonstrate that our tax risk measure explains a substantial portion of UTBs, incremental and relative to measures of information risk, conditional conservatism, unconditional conservatism, and tax avoidance. Our study offers a measure of tax risk that, consistent with the Scholes‐Wolfson paradigm, reflects the tax risk inherent in all business activities, not just tax avoidance activities; has unique industry effects; and contributes to our understanding of the factors that affect tax planning decisions and result in variation in firms' ETRs. Our findings will help managers and tax practitioners focus on industry‐specific tax risk components, assess risk during tax planning initiatives, exercise caution when engaging in additional risk if ETRs are low, and adapt tax risk strategies to fit specific company needs. We enhance future tax research by improving the definition and measurement of tax risk.