We are at post 29 about causation. Yes, 29 posts. That alone should tell you how complex causation has become in federal discrimination law. It is important to take a minute to connect our causation discussion with broader themes about statutory interpretation.
In both Gross and Nassar, the Supreme Court relied on the same argument to justify the results. The common law made them reach a particular result. The common law required certain choices. Whenever you see the Supreme Court using this argument to interpret the federal employment discrimination statutes, it should raise red flags. As we have seen throughout our discussion of causation, the reach to common law masks many choices.
The Court is choosing to look to the common law. With a statute like Title VII, the Court could make another choice—to ignore the common law. Whether to ignore the common law or to embrace it, is an important choice the Court makes.
In Nassar and Gross, the Court is choosing which part of the common law to use and which parts to ignore. In both of these cases, the Court could have looked to the common law and stated that the common law allows a plaintiff to use the substantial factor standard. The Court also could have looked to the common law to justify placing part of the causation burden on the defendant. The Court made important choices about which parts of the common law to use and which parts to ignore.
Interestingly, the Court imports a “but for” cause standard that is typically used in negligence cases into individual disparate treatment cases, which the courts often describe as requiring intentional discrimination.
The idea that tort law demands a particular result is just not true in the discrimination context. Whether to look to tort law is an important choice. It also is important which part of tort law the Court chooses. Tort law did not demand a particular result in either Gross or Nassar. In fact, the Court could have used tort law to justify shifting the causation burden to the defendant and to also require a motivating factor standard of causation.