Law and politics affect the financial structure of the public corporation, perhaps as much as economics. Law restricts financial institutions from holding large equity blocks and from networking the small blocks they do own. Impetus for these restrictions came from several sources: a public-spirited belief that financial stability would be fostered by financial fragmentation, American federalism (each state created its own insular set of financial institutions), rivalries between groups of financial institutions, and popular mistrust of powerful private financial institutions. The stability of many of these rules also derives from the political resistance that one would expect corporate managers and benefited financial institutions to offer to any change.

Ascertaining which enforcement mechanisms work to protect investors has been both a focus of recent work in academic finance and an issue for policy-making at international development agencies. According to recent academic work, private enforcement of investor protection via both disclosure and private liability rules goes hand in hand with financial market development, but public enforcement fails to correlate with financial development and, hence, is unlikely to facilitate it. Our results confirm the disclosure result but reverse the results on both liability standards and public enforcement. We use securities regulators’ resources to proxy for regulatory intensity of the securities regulator. When we do, financial depth regularly, significantly, and robustly correlates with stronger public enforcement. In horse races between these resource-based measures of public enforcement intensity and the most common measures of private enforcement, public enforcement is overall as important as disclosure in explaining financial market outcomes around the world and more important than private liability rules. Hence, policymakers who reject public enforcement as useful for financial market development are ignoring the best currently available evidence.