The politics of opinion assignment: a conditional logit model with varying choice set

"This note replicates and extends Chapter 2 of Forrest Maltzman, James F. Spriggs and Paul J. Wahlbeck's (henceforth: MSW) "Crafting Law on the Supreme Court" (2000). Using a conditional logit model, the authors test the effects of both choice-specific and chooser-specific variables on majority opinion assignment on the United States Supreme Court during Chief Justice Burger's tenure. The authors find that the effect of ideology, as well as other variables, is conditioned on both case facts as well as justices' attributes. In this note, we take issue with the authors' specification of the model, specifically their failure to include choicespecific, i.e. the justices, constants. Below we argue for the statistical necessity of the inclusion of these controls and reassess the original theoretical model with the appropriate statistical specification. We first show that the failure to include these constants will yield biased estimates. We then test if the authors' substantive findings are robust to the correct specification of their original model. While we successfully replicate the original model (yielding biased estimates), we generally find that MSW's core findings, although confirmed, are diminished when correctly estimated." (author's abstract