The Justices’ Words: The Relationship between Majority and Separate Opinions

Majority and separate opinions reflect the justices’ deliberations and strategic decision-making. As justices try to shape the legal outcome, private disagreements during the opinion-writing process spill out into the open, becoming the written words of majority and separate opinions. In this article, I ask how justices use separate opinions to shape the law. I argue that the length of an opinion provides a reasonable proxy of the law and the Court’s decision-making at work. Using time series techniques on the number of words in majority and separate opinions from 1953–2009, I examine whether there is a relationship between the number of words in majority and separate opinions. I demonstrate there is a fractional cointegration relationship between majority and separate opinion length. The majority and separate opinion relationship means there will not be a time in which the Court produces incredibly long separate opinions and succinct majority opinions, or lengthy majority opinions and brief separate opinions. I also find that separate opinion length causes the majority opinion to be shorter or longer. Error correction model results indicate that discussions that occur in one term do not conclude when the Court’s term ends, the effects continue in subsequent terms and cases. The law, as the Court generates it in its majority opinions, is shaped by separate opinions.