Both statutory and constitutional law prohibiting discrimination forbid actions taken on the basis of certain traits. But rarely are those traits specifically defined. As a result, courts fill in these definitions and do so with consequential results. The boundaries they draw often determine whether or not a law, policy or action constitutes disparate treatment on the basis of a legally protected trait. As disparate treatment calls for a significantly heavier burden of justification than does disparate impact, the key move putting laws, policies and the acts of individuals into one category or the other happens in this definitional step. Defining disparate treatment also requires a clear understanding of what taking action “because of” or “on the basis of” a protected trait entails. While the Supreme Court’s 2020 decision in Bostock v. Clayton County took an initial stab at this mechanism question, many ambiguities remain. A clear understanding of disparate treatment requires that we answer both the definition question and the mechanism question. Yet doing so is not easy, a fact that has not been adequately appreciated. To make progress on defining disparate treatment, this Article describes four puzzles, and in so doing develops a research agenda for our times.
Deborah Hellman, Defining Disparate Treatment: A Research Agenda for Our Times, Indiana Law Journal (2023).