Today, we’re beginning another inquiry in our ongoing look at the amicus data at the Court.  We’re looking at two questions, one decade at a time: (1) are amici supporting appellants or appellees more often on the winning side; and (2) one area of law at a time, do amici supporting appellants or amici supporting appellees have the higher winning percentage?  Thus, we take another incremental step (but not the final one) toward determining where amicus briefs are most effective.

Between 1990 and 1999, 178 amicus briefs were filed supporting appellants in civil cases and 78 were filed supporting appellees.  Overall, 72.82% of the appellants’ amici wound up on the winning side, while only 41.82% of the appellees won.

For the decade – leaving aside the areas of law in which only two or three briefs were filed – appellants in government and administrative law cases were the most successful amici, winning 87.5% of the time.  Tort appellants’ amici won 83.72% of their cases.  On the other edge of the spectrum, amici of insurance law appellants won only 58.33% of their cases and constitutional law appellants’ amici won only half the time.  Government and administrative law appellants’ amici were far more successful than appellees’ amici were – as mentioned above, appellants won 87.5% while appellees won none.  Tort appellants’ amici were far more successful than appellees too – 83.72% to 41.18%.  Winning percentages were quite close in three areas of law – civil procedure (66.67% for appellants’ amici, 66.67% for appellees’ amici), constitutional law (50% for appellants’ amici, 42.86% for appellees’ amici), and insurance law (58.33% for appellants’ amici, 61.11% for appellees’ amici).

Join us back here next time as we review the (sparse) data for amici in criminal cases during the 1990s.

Image courtesy of Flickr by Romain Pontida (no changes).