US Supreme Court Openings

With President Obama winning another term there is already talk about his legacy. Now one of the largest parts of a President's legacy is their appointments to the Supreme Court. This got me thinking about the possibility of a retirement; an investigation was required.

There are 103 former Supreme Court justices along with the current 9 justices. I decided to shorten the list by looking only at justices appointed since WW2. There are 20 former justices appointed over this period to analyze.

First there are two ways for a Supreme Court justice seat to open up. A current justice resigning or a current justice dying. Justices dying in office is an unlikely event. Only two justices have died in office both chief justices: Fred M. Vinson and William Rehnquist. Because only 2 of the 20 openings have resulted because of death I feel it appropriate to use age of retirement to calculate openings.

Now the mean age of retirement for justices, that were appointed by Truman onward, is 73.25 with a standard deviation of 9.48. The age at time of death of these former justices, only 17 of died as of the time of writing, is 79.71 with a standard deviation of 8.35.

Looking at the retirement there seemed to be a correlation between age at retirement and year of retirement. After further review there was a modestly strong correlation between the two variables using a 2nd order polynomial.



Using the line of best fit, and its standard deviation, I was able to calculate the probability that each justice will retire in a year. Their age in the table below is on Dec 31, 2012. The percentage under each of the following four years is the probability they will retire based solely on age.

Justice	Age	2013	2014	2015	2016
Ruth Bader Ginsburg	79	66.58%	70.67%	74.54%	78.16%
Anthony Kennedy	76	52.73%	57.28%	61.79%	66.19%
Antonin Scalia	76	52.73%	57.28%	61.79%	66.19%
Stephen Breyer	74	43.19%	47.75%	52.39%	57.05%
Clarence Thomas	64	8.51%	10.45%	12.71%	15.33%
Samuel Alito	62	5.35%	6.73%	8.38%	10.34%
Sonia Sotomayor	58	1.82%	2.40%	3.14%	4.07%
John G. Roberts	57	1.35%	1.80%	2.38%	3.13%
Elena Kagan	52	0.25%	0.35%	0.49%	0.69%

There are four elder justices on the court, two liberal, one staunch conservative and one moderate conservative.

Now obviously this is a rather simplistic way to look at openings. There really isn't a chance that Scalia retires under President Obama. He and Obama are on different sides of the political spectrum. Scalia will only be 80 at the end of Obama's term.

Would Ginsburg risk being replaced by a conservative justice? If so, she might only have 3 years left on the court. There has only been one occurrence of a party holding the presidency for three terms in a row. If she does not retire under Obama she could be 88 or even 92 before she got another chance to retire under a Democratic president.

The next oldest liberal is Breyer at 74 years old. It would be very average to see him retire, fellow liberal Souter retired a few years ago at the age of 70. Breyer would be 78 at the start of the next presidency. If he feels that he has accomplished a lot he could retire and be guaranteed a liberal successor. Otherwise he could continue on and could possibly outlast a two term republican president being 86 years old, 12 years from now.

Kennedy is the trickiest and most important retirement. Kennedy, a moderate conservative, finds himself the swing vote more often than not, and is one of the elder statesmen of the court. If he retires in the next 4 years the court will swing liberal. After that a republican could inhabit the white house and the court would swing even more conservative.