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DW-NOMINATE for US Congress

Source Notebook

Data on political ideology derived from roll-call voting behavior in the US Congress

Details

"Ideological positions are calculated using the DW-NOMINATE (Dynamic Weighted NOMINAl Three-step Estimation). This procedure was developed by Poole and Rosenthal in the 1980s and is a “scaling procedure”, representing legislators on a spatial map. In this sense, a spatial map is much like a road map—the closeness of two legislators on the map shows how similar their voting records are. Using this measure of distance, DW-NOMINATE is able to recover the “dimensions” that inform congressional voting behavior. The primary dimension through most of American history has been “liberal” vs. “conservative” (also referred to as “left” vs. “right”). A second dimension picks up differences within the major political parties over slavery, currency, nativism, civil rights, and lifestyle issues during periods of American history. " (from https://voteview.com/about)

Examples

Basic Examples (1) 

View the data:

In[1]:=
RandomSample[ResourceData[\!\(\* TagBox["\"\<DW-NOMINATE for US Congress\>\"", #& , BoxID -> "ResourceTag-DW-NOMINATE for US Congress-Input", AutoDelete->True]\)], 10]
Out[1]=

Visualization (2) 

Select and group members of the 117th Congress by party, and plot them by both NOMINATE dimensions:

In[2]:=
current = Association /@ GroupBy[Select[ResourceData[\!\(\* TagBox["\"\<DW-NOMINATE for US Congress\>\"", #& , BoxID -> "ResourceTag-DW-NOMINATE for US Congress-Input", AutoDelete->True]\)], #CongressNumber == 117 &], #PartyCode &][All, All, #Name -> {#NominateDim1, #NominateDim2} &]; ListPlot[Values@current[[All, All]], PlotStyle -> {Red, Blue, Darker[Green]}, ImageSize -> Full, PlotTheme -> "Detailed"]
Out[3]=

Plot ideological scores for Republican, Democratic, and "other" parties across all U.S. Congresses:

In[4]:=
dataWithNames = Append[#, <| "PartyName" -> Switch[#PartyCode, 100, "Democratic", 200, "Republican", Except[100 | 200], "Other"]|>] & /@ ResourceData[\!\(\* TagBox["\"\<DW-NOMINATE for US Congress\>\"", #& , BoxID -> "ResourceTag-DW-NOMINATE for US Congress-Input", AutoDelete->True]\)]; jitter[x_] := RandomReal[{x - .5, x + .5}] ListPlot[GroupBy[ dataWithNames[ All, {"CongressNumber" -> jitter}], #PartyName &][{"Democratic", "Republican", "Other"}, All, {"CongressNumber", "NominateDim1"}], PlotStyle -> ({Opacity[0.2], #} & /@ {Blue, Red, Darker[Green]}), PlotRange -> {-1.2, 1.2}, PlotTheme -> "Detailed", ImageSize -> 600]
Out[6]=

Wolfram Research, "DW-NOMINATE for US Congress" from the Wolfram Data Repository (2022)   https://doi.org/10.24097/wolfram.30617.data

Data Resource History

  • Date Created:

Source Metadata

  • Title: Voteview: Congressional Roll-Call Votes Database
  • Creator: Lewis, Jeffrey B., Keith Poole, Howard Rosenthal, Adam Boche, Aaron Rudkin, and Luke Sonnet
  • Date: 1 January 2022
  • Language: English

Data Downloads

Publisher Information

  • Prepared for the Wolfram Data Repository By: C. Alan Joyce
  • Publisher of Record: Wolfram Research