Ruling for the Rich: the Supreme Court over Time

To investigate the emergence of a pro-wealthy bias in the US Supreme Court, we develop a protocol to identify and analyze all cases involving economic issues from 1953 to the present. We categorize the parties in these cases as “rich” or “poor” according to their likelihood of being wealthy. A vote is pro-rich if that outcome would directly shift resources to the party that is more likely to be wealthy. Using this dataset, we estimate case-specific intercepts, justice-specific latent ideal points, and party-level time trends using the Bayesian methods pioneered by Martin and Quinn (2002). In the 1950s, justices appointed by the two parties appear similar in their propensity to cast pro-rich votes. Over the sample period, we estimate a steady increase in polarization, culminating in an implied party gap of 47 percentage points by 2022. The magnitude of the gap suggests the usefulness of an economic metric for prediction relative to ideologies such as originalism or textualism.