We study the observability of investors’ information-acquisition activities in financial markets. Improving observability leads to two strategic effects on information acquisition: (1) the pricing effect, which arises from interactions between investors and the market maker and can encourage or discourage information acquisition, and (2) the competition effect, which concerns interactions among investors and always encourages information acquisition. We apply our theory to study voluntary and mandatory disclosures of corporate site visits. When the competition effect dominates, investors voluntarily disclose their visits. When the pricing effect dominates, mandatory disclosure is effective. Our analysis sheds novel light on Regulation Fair Disclosure.

We study the real effects of certification to demonstrate the value of mandatory certification over and above mandatory disclosure in enhancing investment efficiency. In our model, a firm's manager selects a project to maximize the firm's short‐term stock price, which is a function of her certification and disclosure decisions about the outcome of the project. Although the manager might be either forthcoming or strategic with regard to the disclosure of her private information, she can strategically choose whether to incur a cost or not to certify her disclosure, unless mandated. The manager always selects the first‐best project when both certification and disclosure are mandatory. However, when certification is voluntary, project selection is inefficient. In addition, mandating disclosure without mandating certification can lead to lower investment efficiency than mandating neither. In justifying why mandatory certification is beneficial for public firms, our results offer a note of caution regarding the contemplated regulatory moves for increased disclosures by public firms without corresponding certification requirements, for example, the recent SEC proposal requiring extensive climate‐related disclosure.