Today, we begin a new topic in our analysis of the Illinois Supreme Court’s decision making – the average length of the Court’s majority, special concurrence and dissenting opinions.

In Table 338 below, we report the average length of majority opinions in civil cases between 2000 and 2007, divided into non-unanimous and unanimous decisions of the Supreme Court, as well as an overall average. This chart shows two things: not surprisingly, majority opinions in non-unanimous cases tend to be a longer than in unanimous decisions (although only slightly so), and second, there is some evidence that the Court’s majority opinions were getting longer in the second half of the period.

We begin in 2000 – majority opinions in non-unanimous civil cases averaged 13.88 pages to 10.14 for unanimous decisions. The following year, majorities were up a half page to 14.31 in non-unanimous cases, but majorities in unanimous decisions were up by around a third, to 13.5 pages. Decisions continued to get longer in 2002 – majorities in non-unanimous decisions were up to 16.38 pages, to 15.18 in unanimous ones. In 2003 and 2004, the Court’s opinions stopped edging up, leveling off at 14.13 and 15.44 pages (non-unanimous), and 14.75 and 14.95 pages (unanimous decisions).

But in 2005, the pattern diverged sharply, at least for non-unanimous decisions. The average non-unanimous majority opinion in 2005 more than doubled in length to 32.56 pages. For unanimous decisions, the average majority length was only up by 1.2 pages, to 16.11. The average majority was down only slightly from its high in 2005 to 27.85 pages, while unanimous majorities increased roughly a page and a half, to 17.52. Majority opinions in non-unanimous cases were down even more in 2007, but the average majority (21 pages) was still significantly longer than it had been at any time in the 2000-2004 period. Average opinions in unanimous cases dropped by three-tenths of a page, coming in at 17.16 pages.

Click here for table.