This paper examines the effect of market participants’ information processing costs on firms’ disclosure choice. Using the recent eXtensible Business Reporting Language (XBRL) regulation, I find that firms increase their quantitative footnote disclosures upon implementation of XBRL detailed tagging requirements designed to reduce information users’ processing costs. These results hold in a difference‐in‐difference design using matched nonadopting firms as controls, as well as two additional identification strategies. Examination of the disclosure increase by footnote type suggests that both regulatory and nonregulatory market participants play a role in monitoring firm disclosures. Overall, these findings suggest that the processing costs of market participants can be significant enough to impact firms’ disclosure decisions.

We investigate the frictions that impede individual investors’ use of accounting information and, in particular, their costs of monitoring and acquiring accounting disclosures. We do so using an archival setting in which individuals are presented with automated media articles that report both current earnings news and past stock returns. Although these investors have earnings information readily available, we find no evidence that their trades incorporate it. Instead we find that their trading responds to the trailing stock returns presented in the articles. Our study raises questions about the efficacy of regulations that aim to aid less sophisticated investors by increasing their awareness of and access to accounting information.