  Over the last 23 years, the U.S. Securities and Exchange Commission has
required over 34,000 companies to file over 165,000 annual reports. These
reports, the so-called "Form 10-Ks," contain a characterization of a company's
financial performance and its risks, including the regulatory environment in
which a company operates. In this paper, we analyze over 4.5 million references
to U.S. Federal Acts and Agencies contained within these reports to build a
mean-field measurement of temperature and diversity in this regulatory
ecosystem, where companies are organisms inhabiting the regulatory environment.
While individuals across the political, economic, and academic world frequently
refer to trends in this regulatory ecosystem, far less attention has been paid
to supporting such claims with large-scale, longitudinal data. In this paper,
we document an increase in the regulatory energy per filing, i.e., a warming
"temperature." We also find that the diversity of the regulatory ecosystem has
been increasing over the past two decades, as measured by the dimensionality of
the regulatory space and distance between the "regulatory bitstrings" of
companies. These findings support the claim that regulatory activity and
complexity are increasing, and this measurement framework contributes an
important step towards improving academic and policy discussions around legal
complexity and regulation.
