Adjusted Interest Group Scores
This file contains the R code that I wrote to estimate
adjusted scores. The file is a text file. I recommend viewing it in Microsoft's Notepad.
You can download it to your computer,
and if you understand the R statistical package, you can edit the file so that you can compute your
own adjusted scores. You will need a file of nominal scores (for any interest group you choose), and you will need to edit
my R code to specify where those nominal scores are located on your computer. You can
download (for free!) the R statistical package at this web site.
Details of the estimation process can be found in the article I wrote with Steve Levitt and Jim
Snyder ('Comparing Interest Group Scores across Time and Chambers: Adjusted ADA Scores for the U.S. Congress,'
American Political Science Review, 1999.) Also, please consult the 'Codebook' sheet in the ADA excel file below for
additional details about the method and data sources.
The following excel files contain nominal and adjusted scores for the following interest groups (Note that one
'sheet' of the excel file contains nominal and real scores. Another sheet contains the estimates of the
'a' and 'b' parameters for each year-chamber combination):
Americans for Democratic Action
American Association of University Women
American Civil Liberties Union
American Conservative Union
American Security Council
Chamber of Commerce of the United States
Consumer Federation of America
AFL-CIO's Committee on Political Education
Leadership Conference on Civil Rights
League of Conservation Voters
National Association for the Advancement of Colored People
National Abortion Rights Action League
National Education Association
National Taxpayers' Union