Sunday, July 1, 2012

The SCOTUS and perception of statistics

Finally got internet in the new house.  Can't complain too much....the guy finished running the wire to our house even though a thunderstorm started.  Clearly that man was getting paid by the job, not the hour.

Anyway, had an interesting chat with my father (a lawyer) after our closing on Thursday about the Supreme Court ruling on health care.  He mentioned that a coworker was griping that the Supreme Court meant nothing any more because they only voted on party lines.  My father, being the good data accuracy man that he is, quickly dissented.

He looked it up, and asserted that nearly half of the decisions last year were unanimous.  For this year, 7-2 votes were the least common (8%), then 8-1 (11%), 6-3 (17%) and then 5-4 (20%).  So overall,  they agree nearly as much as they disagree, and they are only completely divided on about 1 in 5 cases.  Kennedy and Roberts voted with the majority over 90% of the time.  Ginsburg was the least likely to vote in the majority.  Lots of interesting stats to be run on this, another good breakdown of some of the data is here.

It seems the perception that every vote is political is heavily skewed by the very few court cases most of us hear about every year.  I would wager even highly political citizens probably couldn't rattle off more than a handful.  When you break down the 5-4 decisions exclusively, about 2/3rds of them vote down ideological lines.....which totals to about 10 cases for 2011.

This kind of skewing of perception is common when a few high profile events dramatically overshadow regular operations.  Thanks Dad, for pointing that out.


  1. Absolutely. I always think it is a form of either projection or base insult. That a person might actually have reasons rather than rationalisations seems impossible to them. The speaker is either saying "That's what I'd do (and differently)" or "my opponents have no principles."

    Either way, they are making statements about themselves, not the court.

    And that goes double for Dahlia Lithwick.

    1. I thought you automatically had to square the effect when the writer was Canadian?

  2. The average person doesn't realize that not very many SC decisions involve political or ideological issues. While all cases should be decided solely on "the law", the perception of the law can differ. But many times, cases that come to the SC simply involve circumstances where a lower court judge got the law wrong and the 9 justices agree on that. In the term that just ended, the figure of over 50% unanimous decisions is historically high but comes at a time when the talking heads spoke quite freely of a polarized court. The actual number paint a different picture.

    1. "The actual number paints a different picture."

      Rather a theme of your daughter's blog. See if you can fit it on an infant T-shirt.