For the past few weeks, we’ve been reviewing the data on how often each of the Justices voted with the majority in non-unanimous civil and criminal cases.  For the next three weeks, we’ll be reviewing a related statistic – how often did each Justice agree with each of his or her individual colleagues on the Court?  Today, we’ll begin a three-week trip through the Court’s recent history on the civil side, then we’ll look at the criminal side.

But first, a few ground rules.  In order to smooth out random variations from year to year, we’ll group the twenty-nine-year period by looking at six years at a time – thus better seeing real relationships and trends.  Second, just as with the last series of posts, “agreement” means complete agreement – a Justice who votes to affirm and another who votes to affirm in part and reverse in part are not counted as agreeing in this data.  Third, because the Court’s unanimity rate is typically so high, we’re addressing non-unanimous decisions only (otherwise, most of these combinations would be clustered relatively high on the bar charts).  Fourth, in the data below, we address every possible combination of Justices who voted in even a single case during these years.

Between 1990 and 1995, Justices Arabian and Baxter had an agreement rate of 83.21%.  Justices Arabian and Eagleson had an agreement rate of 78.57%.  Justices Arabian and Baxter each had an agreement rate with the various pro tem Justices of 66.67%.  Justice Broussard had an agreement rate with Justices Kaufman and Mosk in the fifties – 50% and 56.41%.  Four combinations of Justices had agreement rates in the forties – Justices Arabian and Mosk (42.86%), Justices Baxter and Mosk (45.8%), Justices Broussard and Arabian (45.16%) and Justices Broussard and Eagleson (45.45%).  Justice Broussard had an agreement rate with the pro tems of 36.36%, and Justices Broussard and Baxter (21.43%) and Justice Eagleson and Mosk (27.27%) had agreement rates in the twenties.

Justices Kaufman and Eagleson had an agreement rate during these years of 100%.  Justices George and Baxter’s rate was 82.46%.  Three combinations of Justices had rates in the seventies – Justices Eagleson and the pro tems (71.43%), Justices George and Arabian (77.78%) and Justice George and the pro tems (78.57%).  Justices Kennard and Eagleson had an agreement rate of 63.64%.  Six combinations of Justices had agreement rates in the fifties – Justices Kaufman and Mosk (50%), Justices Kennard and Arabian (51.02%), Justices Kennard and Baxter (51.91%), Justices Kennard and Broussard (56.41%), Justices Kennard and Kaufman (50%) and Justices Kennard and Mosk (54.14%).  Justices George and Mosk had an agreement rate of 48.7%, and Justices Kennard and George had a rate of 48.28%.

Chief Justice Lucas had very high agreement rates with several of his colleagues – Justice Kaufman 100%, Justice Baxter 83.85%, Justice Eagleson 86.36%, Justice George 84.96%, Justice Panelli 86.67%, Justice Arabian 79.59% and Justice Werdegar 80.95%.  On the lower end of the scale were his agreement rates with Justice Kennard – 55.48%, Justice Mosk – 45.81% and Justice Broussard, 38.46%.  The Chief Justice voted with pro tem Justices in 70.37% of divided cases.  Justice Kennard’s agreement rate with Justice Panelli was 56.19%.  She agreed with pro tems 62.07% of the time, and with Justice Werdegar 62.79%.

Justices Panelli had a very high agreement rate with several Justices – Justice Kaufman 100%, Justice Baxter, 92.5% and Justices Eagleson and George, 81.82% and 81.25%, respectively.  Justices Werdegar and Baxter were also in the eighties – 82.93%.  Justices Panelli and Arabian were at 78.72%, and Justice Werdegar had a civil agreement rate in the seventies with Justice Arabian (71.43%) and Justice George (78.05%).  Three different Justices – Panelli, Mosk and Werdegar – had agreement rates in the sixties with the various pro tems (62.5%, 65.52% and 66.67%, respectively).  Justices Werdegar and Mosk had an agreement rate of 54.76%.  Justice Panelli was in the thirties with Justices Broussard (35.9%) and Mosk (39.05%).

Join us back here tomorrow as we explore the Court’s civil agreement rates between 1996 and 2001.

Image courtesy of Flickr by Ron W. (no changes).