Yesterday, we began our review of the year-to-year average length of the Court’s opinions in criminal cases – majority opinions, concurrences and dissents, beginning with the years 1990 to 2003.  Today, we’re looking at the years 2004 through 2017.

Across the entire fourteen-year period, there is some evidence that majority opinions have edged a bit upwards in average length.  Although majority opinions averaged only 32.86 pages in 2004, they averaged 44.12 in 2005, 44.53 in 206, 42.38 in 2008 and 43.45 pages in 2010.  In 2013, the average majority opinion was 46.54 pages.  In 2014, it rose to 47.93 pages.  Although the average majority was 46.31 pages in 2016, it dropped to 30.78 pages in 2017.

Concurrences seemed to be getting a bit longer between 2004 and 2017.  In 2004, the average criminal concurrence was 2.8 pages.  In 2006, it was even lower: 2.38 pages.  In 2013, the average jumped to 8.35 pages.  After a one-year drop, it was at 7 pages in 2015 and 6.33 pages in 2016, before dropping further to 5.4 pages in 2017.

With only a few outliers, dissents in criminal cases varied along a small band from 2004 to about 2013 – generally between roughly nine and twelve pages.  In the few years since, there is some indication that dissents might be getting longer.  The average dissent was 18.09 pages in 2014 and 14.14 pages in 2015.  Although it dropped to 6.6 pages in 2016, it rose back to 16.56 pages in 2017.

Although the average total length of all criminal opinions was increasing from 1990 to 1995, the numbers were relatively consistent from 1996 to 2009 – each year, the average criminal cases produced somewhere from the high forties to mid fifties’ pages of opinions, with no sustained trends upwards or downwards.  In 2012, a spike began, with the average rising to 57.83, followed by 65.71 pages in 2013 and 70.02 pages in 2014.  The average decreased to 59.4 pages in 2015 and 59.24 pages in 2016, before falling back to 52.74 pages in 2017, a number more consistent with the long-term trend.

We concluded last week by calculating the correlation between the yearly averages for majority opinions, concurrences and dissents – in other words, all things being equal, does a longer dissent tend to mean a longer majority opinion?  For criminal cases, there is a relationship between types of opinions, but only a relatively weak one.  The correlation between majority opinions and dissents is 0.3497.  The relationship between majorities and concurrences is a bit stronger, but not substantially so – 0.4419.  Therefore, a longer dissent or concurrence is only a weak-to-middling indication that the majority opinion will be longer.

One final question – is there any correlation between the year-by-year averages for civil and criminal majority opinions?  As we said on the Illinois Supreme Court Review earlier this week, for a variety of reasons, one would expect the answer to be no: civil and criminal are very different areas of law, every case has its own level of complexity, issues, facts, etc.

But in fact, the length of opinions on the one side of the docket is a fairly good predictor of the length of opinions for cases on the other side of the docket.  The correlation between majority opinions in civil and criminal cases from 1990 to 2017 is 0.59472 – moderately high.  The correlation between civil and criminal dissents was nearly as high: 0.527664.  Even the correlation between civil and criminal concurring opinions was moderately high: 0.454033.  As for why that might be, we’ll have to leave that for a future post.

Join us back here next Thursday as we turn to a new area.

Image courtesy of Flickr by Mike Baird (no changes).