Yesterday, we began our analysis of how the Illinois Supreme Court’s majority opinions have changed in the past sixteen years with a look at the civil docket between 2000 and 2007. Today, we review the data for the criminal docket during the same years.

Once again, majority opinions in non-unanimous cases tended to be longer than in unanimous ones, but at least for the first half of the period, the difference was greater than it was on the civil side. In 2000, majorities in non-unanimous criminal cases averaged 21.14 pages to 13.88 pages on the civil side. Majorities in unanimous criminal cases averaged 13.13 pages – significantly less than divided decisions, but not dramatically longer than majorities in unanimous civil cases. Opinions stayed in the same range in 2001 and 2002, both in an absolute and comparative sense. Non-unanimous majorities averaged 20.96 and 21.19 pages, respectively; majorities in unanimous decisions averaged 12.94 and 11.72 pages.

In 2003 and 2004, majority opinions in non-unanimous criminal cases got a bit shorter – 16.42 pages in 2003, 17.08 in 2004. Unanimous majorities, on the other hand, got a bit longer, drawing much closer to the non-unanimous cases. In 2003, the average unanimous criminal majority opinion was 13.68 pages, and the following year, it rose over a page to 14.85.

Among divided decisions, the dip was short-lived, as majorities averaged 21 pages and 20.29 pages in 2005 and 2006. But unanimous majorities got even longer, rising to their highest levels of the period – 16.38 pages in 2005 and 18.29 pages the following year. Although majority opinions in non-unanimous criminal cases tended to be a bit longer than majorities in non-unanimous civil cases for the years 2000-2002, by 2005 and 2006, non-unanimous civil majorities tended to be significantly longer.

The following year showed a curious spike in the data. Majorities in non-unanimous cases jumped by a third in average length to 30.13 pages. But the Court wasn’t writing longer across the board – unanimous civil majorities actually dropped in average length to 15.9 pages.