Scholarship on U.S. litigation and civil procedure has scarcely studied the role of private enforcement in the states. Over the past two decades, scholars have established that, almost uniquely in the world, the U.S. often relies on private parties rather than administrative agencies to enforce important statutory provisions. Take your pick of any area in American governance, and you will find private rights of action: environmental law, civil rights, employment discrimination, antitrust, consumer protection, business competition, securities fraud, and so on. In each of these areas, Congress has deliberately empowered private plaintiffs instead of, or in addition to, government agencies. Yet, despite the vast importance of private enforcement at the federal level, we have no account of how prevalent private rights of action are in state law. And this question is particularly pressing now that a number of states— triggered by the Texas abortion law S.B. 8—are using private enforcement to weaken constitutional rights. Is private enforcement a meaningful method of governance in the states or just at the federal level? Which political conditions lead to the adoption of state private enforcement? And why does it exist?
In this Article, we conduct the first systematic empirical investigation of the hidden world of state private enforcement. Using computational linguistics and machine learning, we identify private-enforcement provisions across a unique dataset of all fifty states’ laws going back to 2003. Our results show that private enforcement is ubiquitous at the state level. Even by conservative estimates, there are more than 3,500 private-rights-of-action provisions in state law, ranging from traditional areas like antitrust and employment all the way to privacy violations, lawsuits against police, gravedigging, veterinary care, and waste disposal. Counterintuitively, private-enforcement provisions are expanding the most in an ideologically mixed group of small states like Utah, New Hampshire, Connecticut, Nebraska, and Wisconsin. One takeaway from these results is that state private enforcement is strikingly different from that of the federal system—it is sprawling, messy, and even chaotic.
We also use our data to test conventional theories behind private-enforcement adoption. The most prominent one—the separation-of-powers theory—posits that Congress enacts private rights of action when the executive is controlled by another political party. Our empirical bottom line is that we broadly fail to find evidence in favor of any of the theories, including separation of powers. Regression analyses based on our best estimates of private-enforcement provisions do not yield a statistically meaningful relationship between divided government and private-enforcement adoption. And, while some of our measures for fee-shifting and damage clauses unearth some evidence pointing toward the separations-of-powers theory, our preferred measures of such clauses do not. We even find no correlation between an increased adoption of private enforcement and legislative control by either Democrats or Republicans. It appears the political economy of private enforcement in the states diverges radically from that of the federal government. With an eye toward future theorizing and empirical testing, we put forth three institutional differences between the states and federal government that may explain this divergence. And we sketch a future comparative research agenda focused on studying federal–state divergence. Reaffirming the central role that private enforcement plays in our system reveals the need to reorient civil procedure and incorporate state private rights of action more explicitly into its core teachings.