We provide evidence on the long-standing concern about the potential conflicts of interest of auditors that provide clients with non-audit services using rarely explored non-audit services fee data from 1978 to 1980. In this setting, we find evidence of improved earnings quality when auditors provide non-audit services, especially those related to information services. This is consistent with better audit quality resulting from knowledge spillovers in the joint offering of audit and consulting services. Events related to the 1982 repeal of mandatory non-audit services disclosures are associated with a small positive stock price reaction, suggesting that the disclosure repeal has no adverse economic consequences. Furthermore, following the repeal we find no change in the earnings quality of client firms. In sum, our data suggest that non-audit services offered by audit firms can be associated with improved audit and reporting quality in client firms via auditors’ reputational incentives, synergies, and knowledge transfers.

We examine how cross-country differences in product, capital, and labor market competition, as well as earnings management affect mean reversion in accounting return on assets. Using a sample of 48,465 unique firms from 49 countries, we find that accounting returns mean revert faster in countries where there is more product and capital market competition, as predicted by economic theory. Country differences in labor market competition and earnings management are also related to mean reversion in accounting returns—but the relation varies with firm performance. Country labor competition increases mean reversion when unexpected returns are positive but slows it when unexpected returns are negative. Accounting returns in countries with higher earnings management mean revert more slowly for profitable firms and more rapidly for loss firms. Thus earnings management incentives to slow or speed up mean reversion in accounting returns are accentuated in countries where there is a high propensity for earnings management. Overall, these findings suggest that country factors explain mean reversion in accounting returns and are therefore relevant for firm valuation.