At the outset of this series of posts, we noted that analytic research has shown a connection between the length of majority opinions and the unanimity rate.  So my next step, now that we’ve reviewed the caseload data from the Appellate Court, will be to compare the unanimity rate to the average length of majority opinions, decade by decade.

As we showed last time, the average length of majority opinions in civil cases in the 1990s was drifting downward – 18.68 pages in 190, 15.94 by 1995 and only 11.9 in 1999.

So did this have an impact on unanimity?

As the table shows, shorter majorities definitely did drive up the unanimity rate for the decade.  In 1990, only 21.59% of the Court’s civil decisions were unanimous.  That was up to 36.84% by 1993, topping out at the end of the decade: 48.33% in 1997, 50% in 1998 and 51.22% in 1999.

Next time, we’ll take a look at the data for criminal cases.

Image: On Chicago River by Walter D. Goldbeck

Image courtesy of Smithsonian American Art Museum (Creative Commons License)