W-NOMINATE Program
Examples
SEN107KH.ORD Data File Name -- can include path statement
NOMINAL MULTIDIMENSIONAL UNFOLDING OF 107th SENATE Title of Run
633 10 18 Number RCs, Left on 1st, Up on 2nd
2 36 Number Dimensions, Number Characters to Read From Header
15.0000 0.5000 Starting Values for BETA and WEIGHT
0.0250 20 RC Min. Cutoff, Number RCs for Legislator
(36A1,3600I1) Format for Roll Call File
(1X,I4,36A1,1X,4I4,51F7.3) Format for Legislator Coordinate File -- NOM31.DAT
(1X,I4,36A1,1X,51F7.3) Format for W-NOMINATE, H-S, and Metric Coordinate File -- NOM36.DAT
C:\DATAFILES\MYROLLCALLS.TXTwhere MYROLLCALLS.TXT is your roll call matrix.
006330001000018 and 0000200036This spacing must not be changed! If you want to analyze 1221 roll calls in 3 dimensions with everything else the same the two lines must look like this:
012210001000018
0000300036
or with the zeroes removed
1221 10 18
3 36
000.025000020If you change these criteria to 5% for the roll calls and 10 for the legislators, then the line must look like this:
000.050000010 or 0.0500 10 or 0.05 10
1079991099 0USA 200 BUSH 111111111999119999999999999991999999999....etc. 1074970041 0ALABAMA 20001SESSIONS 111111111111111611111611111111166661611....etc. 1079465941 0ALABAMA 20001SHELBY 111111111111111611111611111111166611611....etc.There are 36 columns before the first roll call and then each roll call is only one digit in width.
(1X,I4,41A1,1X,4I4,51F7.3)
(1X,I4,41A1,1X,51F7.3)
SEN107KH.ORD
NOMINAL MULTIDIMENSIONAL UNFOLDING OF 107th SENATE
633 10 18 The lines in red simply echo back
2 36 the corresponding lines in NOMSTART.DAT
15.0000 0.5000
0.0250 20
(36A1,3600I1)
(1x,I4,36A1,1X,4i4,51f7.3)
(1x,I4,36A1,1X,51f7.3)
DATA 0 0 Read in Data: Total CPU time, CPU time of Read
CLEAN 0 0 Throw out Unscalable RCs and Legislators: Total CPU time, CPU time of Clean
STARTS 1 1 Generate Legislator Starts: Total CPU time, CPU time of Starts
RECODE 1 0 Generate Roll Call Starts: Total CPU time, CPU time of Recode
1 47 6 1.000 -1.000 1.000
PERCENT CLASSIFIED= 89.134 AGGREGATE PRE= 0.687
1 1 1 6 5 -12229.7295 0.7610 0.6352 0.6621
1 2 2 6 0 -11498.9316 0.7735 0.9959
1 3 0 7 1 -11493.0479 0.7736 0.6785 15.2322 0.5296
PERCENT CLASSIFIED= 89.266 AGGREGATE PRE= 0.691
1 4 1 11 4 -11986.9141 0.7651 0.9957 0.9939
1 5 2 11 0 -11385.1641 0.7755 0.9990
1 6 0 12 1 -11375.5322 0.7756 0.9955 15.9184 0.5307
PERCENT CLASSIFIED= 89.270 AGGREGATE PRE= 0.691
1 7 1 15 3 -11947.9150 0.7658 0.9937 0.9996
1 8 2 16 1 -11350.7012 0.7761 0.9999
1 9 0 17 1 -11342.5059 0.7762 0.9955 16.7035 0.5276
PERCENT CLASSIFIED= 89.286 AGGREGATE PRE= 0.692
1 10 1 20 3 -11946.8047 0.7658 0.9983 0.9997
SAG IN RECOVERED LEGISLATOR COORDINATES
110729142 5 0RHODE I 10001REED 294 20 6 136 -1.000
11071303952 0MARYLAN 10001SARBANES 304 11 5 137 -1.000
11071501171 0CALIFOR 10001BOXER 281 22 8 131 -1.000
11071410547 0NORTH C 20001HELMS 115 15 10 188 0.931
11071462849 0TEXAS 20001GRAMM, PHIL 171 24 13 233 0.984
11071542961 0ARIZONA 20001KYL 171 33 9 242 1.000
CONSTRAINED UNCONSTRAINED
OFF OPPOSITE OFF SAME
42 74 341
2 7 36 1.633 -1.528 1.000
PERCENT CLASSIFIED= 89.172 AGGREGATE PRE= 0.688
2 11 1 21 1 -10584.7471 0.7895 0.0000 0.0027
2 12 2 22 1 -10520.0684 0.7906 0.0009
2 13 -1 23 1 -10643.2773 0.7884 0.0025 16.7035 0.5189
PERCENT CLASSIFIED= 90.007 AGGREGATE PRE= 0.712
2 14 1 24 1 -10577.8984 0.7896 0.8803 0.7860
2 15 2 25 1 -10493.7646 0.7911 0.9689
2 16 -1 25 0 -10552.6006 0.7900 0.8437 16.7035 0.5397
PERCENT CLASSIFIED= 90.074 AGGREGATE PRE= 0.714
2 17 1 27 2 -10521.1230 0.7906 0.9449 0.8791
2 18 2 27 0 -10455.6855 0.7917 0.9891
2 19 -1 28 1 -10507.5830 0.7908 0.9190 16.7035 0.5620
PERCENT CLASSIFIED= 90.099 AGGREGATE PRE= 0.715
2 20 1 29 1 -10500.7441 0.7909 0.9883 0.9301
SAG IN RECOVERED LEGISLATOR COORDINATES
110714240 6 0VERMONT 20001JEFFORDS 63 14 6 57 -0.999
11071503961 0ARIZONA 20001MCCAIN 173 43 57 169 -0.953
110749905 5 0RHODE I 20001CHAFEE 212 43 48 153 -0.891
11071420364 0MONTANA 10001BAUCUS 266 48 17 114 0.931
11071305645 0LOUISIA 10001BREAUX 272 32 28 120 0.989
11074010335 0NEBRASK 10001NELSON, BEN 275 30 22 129 0.992
CONSTRAINED UNCONSTRAINED
OFF OPPOSITE OFF SAME
92 62 303
11.37.52.28.
ELAPSED TIME OF JOB 11.38.21.96.
NOMINAL MULTIDIMENSIONAL UNFOLDING OF 107th SENATE ROLL-CALLS READ= 633 NUMBER REJECTED= 176 NUMBER ACCEPTED= 457 CUTOFF= 0.025 LEGISLATORS READ= 103 NUMBER REJECTED= 1 NUMBER ACCEPTED= 102 CUTOFF= 20 DISTRIBUTION OF SCALABLE ROLL CALLS 1 50 - 55 128 0.280 2 56 - 60 98 0.214 3 61 - 65 51 0.112 4 66 - 70 44 0.096 5 71 - 75 30 0.066 6 76 - 80 27 0.059 7 81 - 85 18 0.039 8 86 - 90 21 0.046 9 91 - 95 26 0.057 10 96 - 99.5 14 0.031This is the output for an eigenvalue-eigenvector decomposition of the double-centered, symmetric, legislator by legislator agreement score matrix and the Heckman-Snyder covariance matrix. The 2nd column shows the eigenvalues of the double-centered agreement score matrix, the third column is the percent variation explained, and the fourth is the total variation explained. Columns 5-7 are for the decomposition of the H-S covariance matrix.
PERFORMANCE INDEX EIGENVALUE/VECTOR ROUTINE= 2 102 0 0 PERFORMANCE INDEX EIGENVALUE/VECTOR ROUTINE= 2 102 0 0 1 10.7676 70.3183 70.3183 12.4941 58.0379 58.0379 2 0.3445 2.2495 72.5677 0.7742 3.5965 61.6344 3 0.3141 2.0512 74.6189 0.5320 2.4711 64.1055 4 0.2055 1.3420 75.9609 0.4132 1.9195 66.0251 5 0.1794 1.1717 77.1326 0.3487 1.6197 67.6447 6 0.1542 1.0068 78.1394 0.2972 1.3807 69.0254 7 0.1458 0.9523 79.0917 0.2747 1.2761 70.3015 8 0.1209 0.7894 79.8810 0.2413 1.1207 71.4223 9 0.1071 0.6996 80.5807 0.2141 0.9944 72.4167 10 0.0929 0.6064 81.1871 0.2071 0.9620 73.3787 11 0.0887 0.5791 81.7662 0.1954 0.9076 74.2864 12 0.0813 0.5313 82.2974 0.1777 0.8253 75.1116 13 0.0773 0.5048 82.8023 0.1684 0.7821 75.8937 14 0.0691 0.4514 83.2537 0.1655 0.7687 76.6624 15 0.0627 0.4096 83.6633 0.1553 0.7216 77.3840 16 0.0585 0.3822 84.0455 0.1523 0.7076 78.0916 17 0.0542 0.3541 84.3996 0.1491 0.6925 78.7841 18 0.0513 0.3352 84.7348 0.1441 0.6695 79.4536 19 0.0482 0.3151 85.0498 0.1400 0.6505 80.1040 20 0.0451 0.2944 85.3442 0.1315 0.6110 80.7150The eigenvalues of the double-centered agreement score matrix are very useful for making a Skree plot like the one below. The "elbow" gives the user a pretty good indication of the dimensionality of the data.

0 1371.27405 0.97102 0.00000 5151 1 128.96994 0.96999 0.90595 5151 2 63.48307 0.97747 0.50777 5151 3 52.60210 0.98008 0.17140 5151 4 47.91137 0.98065 0.08917 5151 5 45.17076 0.98066 0.05720 5151 6 43.43190 0.98053 0.03850 5151 7 42.26067 0.98041 0.02697 5151 8 41.43574 0.98032 0.01952 5151 9 40.83847 0.98028 0.01441 5151 10 40.39579 0.98027 0.01084 5151The Starting values of the Legislator coordinates are adjusted so that the furthest left individual is set to -1 and the furthest right is set to +1. The estimated coordinates are reported before the adjustment is made. Note that this is a simple linear transformation.
NUMBER LEGISLATORS= 102 FURTHEST LEFT= -0.6087 FURTHEST RIGHT= 0.6125 POSITIONS: LEFT= 47 RIGHT= 6After each roll call phase, the cross-tabulation of the classifications is reported.
TOTAL VOTES PREDICTED FOR 457 ROLL-CALLS
ACTUAL
YEA NAY
YEA 24229 2781
NAY 2084 15678
After each legislator phase, the cross-tabulation of the classifications
is reported.
TOTAL VOTES PREDICTED FOR 102 LEGISLATORS
ACTUAL
YEA NAY
YEA 24182 2728
NAY 2131 15731
Numerous other diagnostics are reported in the file but these are really useful
for de-bugging purposes only. If you wish any information about them just send
e-mail to me at KPoole@ucsd.edu and I would be
happy to answer any questions that you may have.(1X,I4,36A1,1X,4I4,51F7.3)The "1X,I4" tells W-NOMINATE to write out a simple integer counter from 1 to the number of scaled legislators. The "36A1" is the number of characters on each line of the roll call data file before the roll calls begin. Most users only need to change the "36" wherever it appears in NOMSTART.DAT. The "4I4" handles the cross-classifications and the "51F7.3" handles the coordinates and measures of fit. If you have problems with the formatting of files please send me an e-mail at KPoole@ucsd.edu and I would be happy to answer any questions that you may have.
11079991099 0USA 200 BUSH 32 0 1 20 0.922 0.761 0.208 0.296 2.503
21074970041 0ALABAMA 20001SESSIONS 172 27 32 213 0.785 0.641 -0.437 0.037 0.097
31079465941 0ALABAMA 20001SHELBY 195 33 33 186 0.739 0.505 -0.158 0.031 0.095
41071490781 0ALASKA 20001MURKOWSKI 198 15 13 194 0.828 0.632 0.464 0.039 0.169
51071210981 0ALASKA 20001STEVENS 210 18 21 163 0.781 0.518 0.307 0.036 0.138
etc etc
The first column is an integer counter
The column in red is the Congress number
The column in blue is the ICPSR ID Number
The column in Magenta is the ICPSR State Code
The column of zeroes will show the two digit Congressional District Number for House Roll Call Matrices
The column in Coral is the first seven letters of the State Name
The column in Midnightblue is the party code -- see the Party Codes Page for a complete listing
The column in Firebrick are the ICPSR Occupancy and Election Codes
Name of Senator/Representative
The cross classification is in Turquoise.
The second and third columns are classification errors -- predicted yes voted no and predicted
no voted yes. So for Bush
correct classification = (32+20)/(32+20+0+1) = 98.1%
The column in Purple is the Geometric Mean Probability
The two columns in Green are the Legislator coordinates
The last two columns in Deeppink are the Conditional Standard Errors
etc etc
981071492256 0WEST VI 10001ROCKEFELLER 298 21 18 117 0.821 -0.741 -0.096 0.039 0.127
991074930925 0WISCONS 10001FEINGOLD 240 75 20 122 0.697 -0.727 -0.686 0.031 0.119
1001071570325 0WISCONS 10001KOHL 300 20 21 104 0.801 -0.581 0.155 0.035 0.139
1011074970668 0WYOMING 20001ENZI 187 30 9 219 0.821 0.777 0.397 0.039 0.183
1021071563368 0WYOMING 20001THOMAS 190 22 8 228 0.845 0.842 0.313 0.049 0.199
The Conditional Standard Errors are known to under-report the true uncertainty in
the legislator coordinates (see the Appendix to
Congress: A Political-Economic History of Roll
Call Voting).
Jeff Lewis and I have
computed Legislator Coordinate
files with parametric bootstrapped standard errors for all Houses and Senates in
American History. They can be found on the
Parametric Bootstrap Page. For an explanation of
how these are computed see:
1 6 0 69 4 7 20 0.770 0.542 -0.774 -0.715 0.084 0.035 0.303 0.053 0.088 0.501
2 8 0 53 0 6 42 0.865 0.857 -0.694 -0.331 0.284 0.123 0.264 0.134 0.090 0.201
3 15 0 53 1 3 43 0.897 0.909 -1.207 -0.327 0.024 0.266 0.600 0.068 0.098 1.484
4 16 0 31 6 3 59 0.813 0.735 0.878 -0.557 -0.186 0.148 0.383 0.047 0.100 0.288
5 17 0 51 2 7 39 0.826 0.780 -0.736 -0.373 0.013 -0.598 0.322 0.075 0.052 1.321
etc etc
The first column is an integer counter
The column in red is position of the roll call in the file
The column in blue indicates if the roll call is constrained:
0 = unconstrained
1 = Zmid at the rim of the unit hypersphere
If this Variable is 1, the standard errors in the last four columns are meaningless
The cross classification is in Turquoise. For the First Vote:
ACTUAL
Yea Nay
Yea 69 4
PREDICTED or 89/100 = 89% correct
Nay 7 20
The column in Purple is the Geometric Mean Probability
The column in Firebrick is the Proportional Reduction in Error (PRE)
[PRE = (number voting in minority - classification errors)/number voting in minority]
For the first vote this is (24 - 11)/24 = .542
The columns in Coral are in order:
Spread First Dimension
Midpoint First Dimension
Spread Second Dimension
Midpoint Second Dimension
The columns in Midnightblue are the corresponding Conditional Standard Errors
etc etc
453 628 1 78 6 4 10 0.801 0.375 -1.189 -0.813 -0.007 0.582 0.600 0.045 0.056 1.114
454 629 1 90 9 0 0 0.810 0.000 -0.690 -1.000 0.000 0.000 0.388 0.120 0.067 1.760
455 630 0 50 0 6 43 0.847 0.860 -0.708 -0.291 0.166 0.212 0.271 0.114 0.092 0.300
456 631 0 83 8 1 4 0.794 0.250 0.769 0.829 -0.004 0.524 0.484 0.089 0.073 1.856
457 632 0 86 8 0 3 0.801 0.273 0.780 0.858 0.029 0.006 0.536 0.087 0.093 2.377
(1X,I4,36A1,1X,51F7.3)The "1X,I4" tells W-NOMINATE to write out a simple integer counter from 1 to the number of scaled legislators. The "36A1" is the number of characters on each line of the roll call data file before the roll calls begin. Most users only need to change the "36" wherever it appears in NOMSTART.DAT. The "1X,51F7.3" handles the coordinates that are written to the file. This file is identical to NOM31.DAT through the name of the legislator. NOM36.DAT looks like this:
11079991099 0USA 200 BUSH 0.761 0.208 0.973 0.090 0.544 0.108
21074970041 0ALABAMA 20001SESSIONS 0.641 -0.437 0.790 -0.109 0.453 -0.423
31079465941 0ALABAMA 20001SHELBY 0.505 -0.158 0.665 -0.028 0.361 -0.332
41071490781 0ALASKA 20001MURKOWSKI 0.632 0.464 0.813 -0.009 0.464 0.316
51071210981 0ALASKA 20001STEVENS 0.518 0.307 0.692 0.006 0.375 0.413
etc etc
The columns in red are the W-NOMINATE Coordinates -- Same as NOM31.DAT
The columns in blue are the Heckman-Snyder Coordinates rotated to best match the W-NOMINATE Coordinates
The columns in magenta are the Metric Scaling Coordinates rotated to best match the W-NOMINATE Coordinates
etc etc
981071492256 0WEST VI 10001ROCKEFELLER -0.741 -0.096 -0.843 -0.030 -0.483 -0.035
991074930925 0WISCONS 10001FEINGOLD -0.727 -0.686 -0.746 -0.302 -0.519 -0.855
1001071570325 0WISCONS 10001KOHL -0.581 0.155 -0.702 0.180 -0.375 0.140
1011074970668 0WYOMING 20001ENZI 0.777 0.397 0.846 -0.139 0.529 0.039
1021071563368 0WYOMING 20001THOMAS 0.842 0.313 0.877 -0.192 0.552 0.052
HOU96KH.ORD
NOMINAL MULTIDIMENSIONAL UNFOLDING
1276 1 4
2 36
15.0000 0.5000
0.0250 20
(36A1,3600I1)
(1x,I4,36A1,1X,4i4,51f7.3)
(1x,I4,36A1,1X,51f7.3)
DATA 0 0
CLEAN 0 0
STARTS 35 35
RECODE 35 0
1 173 94 1.000 -1.000 1.000
PERCENT CLASSIFIED= 84.034 AGGREGATE PRE= 0.464
1 1 1 63 28 -153741.0310 0.6920 0.5634 0.4737
1 2 2 71 8 -148005.8120 0.7016 0.9849
1 3 0 91 20 -148009.2190 0.7015 0.5760 13.6244 0.5749
PERCENT CLASSIFIED= 84.255 AGGREGATE PRE= 0.472
1 4 1 111 20 -149193.2970 0.6996 0.9779 0.9350
1 5 2 118 7 -146960.5000 0.7033 0.9972
1 6 0 125 7 -146960.3120 0.7033 0.9618 13.5915 0.5879
PERCENT CLASSIFIED= 84.282 AGGREGATE PRE= 0.473
1 7 1 144 19 -148714.0940 0.7004 0.9939 0.9746
1 8 2 150 6 -146809.5310 0.7036 0.9994
1 9 0 162 12 -146801.5940 0.7036 0.9873 13.8950 0.5815
PERCENT CLASSIFIED= 84.280 AGGREGATE PRE= 0.473
1 10 1 181 19 -148866.5310 0.7001 0.9938 0.9626
SAG IN RECOVERED LEGISLATOR COORDINATES
1 96142691314NEW YOR 10001RICHMOND F 521 34 15 312 -1.000
0 961303152 7MARYLAN 10001MITCHELL P 530 95 18 337 -1.000
1 961301171 8CALIFOR 10001DELLUMS R 502 77 15 342 -1.000
1 961073463 2IDAHO 20001HANSEN G 407 50 23 465 1.000
0 961425244 7GEORGIA 10001MCDONALD L 404 90 32 508 1.000
1 96142904922TEXAS 20001PAUL R 382 119 59 476 1.000
CONSTRAINED UNCONSTRAINED
OFF OPPOSITE OFF SAME
29 165 873
2 137 328 1.359 -1.230 1.000
PERCENT CLASSIFIED= 84.235 AGGREGATE PRE= 0.471
2 11 1 193 11 -136035.0780 0.7220 0.0015 0.0005
2 12 2 203 10 -134958.9530 0.7238 0.0006
2 13 -1 211 8 -135535.4530 0.7228 0.0002 13.8950 0.5071
PERCENT CLASSIFIED= 85.875 AGGREGATE PRE= 0.526
2 14 1 222 11 -135435.2030 0.7230 0.8735 0.7097
2 15 2 228 6 -134953.3440 0.7238 0.9819
2 16 -1 236 8 -135133.7660 0.7235 0.8729 13.8950 0.5152
PERCENT CLASSIFIED= 85.840 AGGREGATE PRE= 0.525
2 17 1 246 10 -135109.0160 0.7236 0.9260 0.8763
2 18 2 252 6 -134867.3910 0.7240 0.9983
2 19 -1 269 17 -135058.1720 0.7236 0.9442 13.8950 0.5232
PERCENT CLASSIFIED= 85.826 AGGREGATE PRE= 0.524
2 20 1 279 10 -135065.2030 0.7236 0.9884 0.9362
SAG IN RECOVERED LEGISLATOR COORDINATES
1 9614240 6 1VERMONT 20001JEFFORDS J 446 118 87 277 -1.000
1 961422112 5NEW JER 20001FENWICK M 448 187 90 307 -0.997
1 961405162 1COLORAD 10001SCHROEDER 429 158 97 300 -0.987
1 96146744914TEXAS 10001WYATT J 598 66 88 226 0.991
1 961078847 1NORTH C 10001JONES W 543 72 54 238 0.998
1 961100041 4ALABAMA 10001BEVILL T 612 61 50 252 1.000
CONSTRAINED UNCONSTRAINED
OFF OPPOSITE OFF SAME
93 129 845
15.18.40.40.
ELAPSED TIME OF JOB 15.23.20.51.
The correct classification is 85.826% with an APRE of 0.524 and a
geometric mean probability of .7236. The
96th (1979-80) House was part of the 3-Party period from the
late 1930s to the mid-1980s when the Democratic Party was split into Northern
and Southern blocs (see my book with Howard Rosenthal
Congress: A Political-Economic History of Roll Call
Voting, our paper D-NOMINATE After 10 Years: A
Comparative Update to Congress: A Political-Economic History of Roll Call
Voting [a version of this paper was published in
Legislative Studies Quarterly, 26:5-29, 2001], and my monograph
with Nolan McCarty and Howard Rosenthal
Income Redistribution
and the Realignment of American Politics, 1997, AEI Press. Congressional
voting through this period was two dimensional.
