Predictions of the 10th Justice: Grading the Predictions for Citizens United (Hillary Movie Case), or Proving the Wisdom of the Crowds

January 22nd, 2010

Welcome to the seventh installment of Predictions of the 10th Justice, brought to you by The league has over 3,500 members, who have made predictions on all cases currently pending before the Supreme Court.

Today, the Supreme Court handed down Citizens United v. FEC, one of the most anticipated cases of the year. The Hillary Movie case was a showdown between free speech and campaign finance laws. In 2008, the D.C. Circuit ruled in favor of the FEC that Hillary: The Movie could not be shown on television right before the 2008 Democratic primaries under the McCain-Feingold Act.

In a 5-4 decision, Justice Kennedy reversed the lower court. The Court found that sections of the McCain-Feingold Act limiting contributions by corporations for advocacy advertisements violated the First Amendment, and were unconstitutional.

This is the first blockbuster case of the term, and the first real yardstick for the accuracy of the wisdom of the crowds. Were our 3,500 members able to accurately predict this outcome? How wise is the wisdom of our crowds?

On November 20, 2010, based on 286 prediction, 67% of our members predicted that the Supreme Court would reverse the lower court. Of these 286 predictions, 136 members predicted that the outcome would be a 5-4 reversal. This constituted 70% of all reversal predictions.

But since November, our league acquired over 2,000 new members, who made 600 additional predictions for this case. How did they do?

More, after the jump.

As of Wednesday, January 20, 2010, based on 906 predictions, 61% (557 members) correctly predicted that the Court would reverse the lower court. Of these 906 predictions, 385 members (42%) correctly predicted that the outcome would be a 5-4 reversal.

The results based on 286 predictions almost mirrored the results based on 906 members.

November 20, 2009

January 20, 2010

Comparing the predictions in November to the predictions in January yields a similar picture with respect to the composition of the majority and minority blocs. The primary difference is that the main majority prediction dropped 10 percentage points lower while the main minority predictions were slightly higher and more equalized.

November 20, 2009

January 20, 2010

In both cases, the predictions in November were more accurate than the predictions in January. Why were the more recent predictions likely to be wrong? Perhaps the Supreme Court’s lengthy delay in releasing the opinion caused some concern and trepidation that the Court was uncertain how to proceed? Perhaps some feared that Justice Kennedy’s vote would switch to the other side?

Regardless of the reason for the drop in accuracy of the predictions from November to January, well over a third of all predictions got the correct combination of justices in the majority. Combined with the other results, it seems that the predictions of the 10th Justice are an accurate predictor of the actual outcome of Supreme Court cases. The wisdom of the crowds is quite wise in this case.

And here is the updated scoreboard:

1 kedarbhatia 98
2 justindonoho 92
3 AdamGU 90
4 snitty 89
5 VaIsForLawyers 89
6 pmacmahon 86
7 DNJ 83
8 bannana873 82
9 prgugliuzza 81
10 Melech 80

Many thanks to Corey Carpenter for his assistance with this post.