These datasets contain the Martin-Quinn scores for the October 1937 through the October 2021 term of the U.S. Supreme Court. The Justices dataset contains the ideal point estimates and other quantities of interest for each justice in each term. The Court dataset contains court-specific quantities, including the estimated location of the median justice. All datasets are provided as ASCII text files, Stata DTA files, Microsoft Excel spreadsheets, and SPSS SAV files. We ask that if you use these scores in your work, please cite the following article:
Andrew D. Martin and Kevin M. Quinn. 2002. "Dynamic Ideal Point Estimation via Markov Chain Monte Carlo for the U.S. Supreme Court, 1953-1999." Political Analysis. 10:134-153. [PDF]
These scores are based on the 2021 Release 01 release of the Supreme Court Database and the SCDB Legacy 03 version of the Legacy Supreme Court Database. See README for more details.
THE 2021 JUSTICE DATA FILES
justices.csv
justices.dta
justices.xls
justices.sav
Each file contains these variables:
| Variable | Description |
| term | Term |
| justice | Supreme Court Database unique justice identifier |
| justiceName | Justice last name |
| code | Supreme Court Database justice code |
| post_mn | Estimated Martin-Quinn score (posterior mean) |
| post_sd | Martin-Quinn score posterior standard deviation |
| post_med | Martin-Quinn score posterior median |
| post_025 | Martin-Quinn score 2.5 percentile |
| post_975 | Martin-Quinn score 97.5 percentile |
NOTE: We recommend using the posterior mean (post_mn) as the estimate the ideal point of each justice in each term.
THE 2021 COURT DATA FILES
court.csv
court.dta
court.xls
court.sav
Each file contains these variables:
| Variable | Description |
| term | Term |
| med | Location of the median justice (posterior mean) |
| med_sd | Posterior standard deviation of the median justice |
| min | Location of the minimum justice (posterior mean) |
| max | Location of the maximum justice (posterior mean) |
| justice | Justice most likely to be median |
| just_pr | Probability of most likely justice |
| Harlan-Stone | Probabilities each justice is median in each term |
NOTE: We recommend using the posterior mean location (med) for the median justice. In order to better understand the Court (including the median justice) in terms with turnover, our Court dataset now includes separate records for terms in which a justice resigned and his or her replacement was confirmed and seated during a term. This happened in the 1937 term (Reed replaced Sutherland), 1938 term (Douglas replaced Brandeis), 1956 term (Whittaker replaced Reed), and the 2005 term (Alito replaced O'Connor).
Please contact us if you have any problems or questions about these measures.
LEGACY DATA FILES
2021 MQ Scores Data
2020 MQ Scores Data
2019 MQ Scores Data
2018 MQ Scores Data
2017 MQ Scores Data
2016 MQ Scores Data
2015 MQ Scores Data
2014 MQ Scores Data
2013 MQ Scores Data (Release 2)
2013 MQ Scores Data
2012 MQ Scores Data
2011 MQ Scores Data
2010 MQ Scores Data
2009 MQ Scores Data
2008 MQ Scores Data
2007 MQ Scores Data
2006 MQ Scores Data
2005 MQ Scores Data
2004 MQ Scores Data
2003 MQ Scores Data
2002 MQ Scores Data
2000 MQ Scores Data
1999 MQ Scores Data
