We examine whether firms respond to settlements of their uncertain tax benefits (UTBs) by adjusting the related UTB reserve. A reported UTB settlement indicates that the tax authority challenged at least one of the firm’s uncertain tax positions, thereby providing information to managers regarding the sustainability of similar tax strategies and outstanding UTBs. Consistent with expectations, our results suggest that UTB settlements are negatively related to the accrual for new uncertain tax positions. Further, we demonstrate that managers make less downward adjustments to the UTB reserve related to existing uncertain tax positions following settlements with tax authorities. Finally, additional analysis suggests that the valuation of UTBs is lower in the year subsequent to a UTB settlement. Collectively, our results suggest that the information gathered from tax audit outcomes influences firms to be more conservative in their tax reporting, and possibly their future tax planning as well.

We investigate whether accounting conservatism can be explained as a rational response to ambiguity. Decision analysis shows that decision rules that work well under ambiguity put greater weight on negative than on positive outcomes, i.e., exhibit caution. Accounting conservatism increases the timeliness of bad news that is more relevant under cautious decision rules and thereby helps corporate managers and investors implement them. We, therefore, hypothesize that firms facing greater ambiguity report more conservatively. We adopt two different measures to proxy for the firm-specific level of ambiguity. First, we identify firms pursuing the “prospector” versus “defender” business strategies. Compared with defenders, who focus on utilizing existing resources, prospectors actively create their future by seeking new business opportunities and thus face greater ambiguity. Second, we conduct an additional set of tests based on environmental scanning, which reduces ambiguity. Both sets of results suggest that firms facing greater ambiguity report more conservatively.