The last causation post discussed Justice O’Connor’s concurrence in Price Waterhouse. Justice White also concurred in the judgment in Price Waterhouse and offered a different reasoning for the outcome. Justice White agreed that a substantial factor test was appropriate for Title VII disparate treatment cases. However, he did not arrive at this test through a tort causation analysis. Instead, Justice White applied the reasoning used in Mt. Healthy City Bd. of Ed. v. Doyle, 429 U.S. 274 (1977), a case considering the causation question in the context of a public employee who alleged he was not rehired because of his exercise of his First Amendment rights. In Mt. Healthy, the Court placed the initial burden on the worker to establish that his conduct was a substantial or motivating factor in the decision. The employer would then be required to show by a preponderance of the evidence that it would have reached the same decision even in the absence of the conduct protected by the First Amendment.
Justice White noted that he agreed with both the plurality and with Justice O’Connor about the way the test should operate. Justice White disagreed about how to reach that result. He did not think Justice O’Connor’s tort-based “but for” cause analysis was necessary. Rather, the motivating factor test could be justified by applying Mt. Healthy to Title VII cases.
Justice White also opined about the intersection of the motivating or substantial factor test with the existing McDonnell Douglas framework. He characterized these two tests as separate from one another. He believed the McDonnell Douglas test should be used in cases where there was only one reason for an employment decision and that the substantial or motivating factor test should be used when both legitimate and discriminatory motives may be at work.