Correcting for small group inflation of roll-call cohesion scores

British Journal of Political Science

Volumn 35, Issue 4, 2005, Pages 731-744

  Desposato, Scott W ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 25444491712     PISSN: 00071234     EISSN: None     Source Type: Journal    
DOI: 10.1017/S0007123405000372     Document Type: Review

References (52)

1. Stewart A. Rice, 'Farmers and Workers in American Polities' (doctoral dissertation, Columbia University, 1924).
2. A few examples include Stewart A. Rice, Quantitative Methods in Politics (New York: Alfred A. Knopf, 1928);
3. V. O. Key Jr, Southern Politics in State and Nation (New York: Alfred A. Knopf, 1949);
4. David Truman, 'The State Delegations and the Structure of Party Voting in the United States House of Representatives', American Political Science Review, 50 (1956), 1023-45;
5. Charles Press, 'Presidential Coattails and Party Cohesion', Midwest Journal of Political Science, 7 (1963), 320-35;
6. Allan Kornberg, 'Caucus and Cohesion in Canadian Parliamentary Parties', American Political Science Review, 60 (1966), 83-92;
7. Hugh L. LeBlanc, 'Voting in State Senates: Party and Constituency Influences', Midwest Journal of Political Science, 13 (1969), 33-57;
8. Helmut Norpoth, 'Explaining Party Cohesion in Congress: The Case of Shared Policy Attitudes', American Political Science Review, 70 (1976), 1156-71;
9. Hugh W. Stephens and David W. Brady, 'The Parliamentary Parties and the Electoral Reforms of 1884-85 in Britain', Legislative Studies Quarterly, 1 (1976), 491-510;
10. David B. Meltz, 'Legislative Party Cohesion: A Model of the Bargaining Process in State Legislatures', Journal of Politics, 35 (1973), 647-81;
11. Keith E. Hamm, Robert Harmel and Robert J. Thompson, 'Impacts of Districting Change on Voting Cohesion and Representation', Journal of Politics, 43 (1981), 544-55;
12. E. Lee Bernick, 'The Impact of U. S. Governors on Party Voting in One-Party Dominated Legislatures', Legislative Studies Quarterly, 3 (1978), 431-44;
13. Gary W. Cox and Matthew D. McCubbins, 'On the Decline of Party Voting in Congress', Legislative Studies Quarterly, 16 (1991), 547-70;
14. David M. Wood and Jack T. Pitzer, 'Parties, Coalitions, and Cleavages: A Comparison of Two Legislatures in Two French Republics', Legislative Studies Quarterly, 4 (1979), 197-226;
15. Hans-Peter Hertig, 'Party Cohesion in the Swiss Parliament', Legislative Studies Quarterly, 3 (1978), 63-81;
16. Barbara Deckard Sinclair, 'Determinants of Aggregate Party Cohesion in the U. S. House of Representatives, 1901-1956', Legislative Studies Quarterly, 2 (1977), 155-75;
17. Moshe Haspel, Thomas F. Remington and Steven S. Smith, 'Electoral Institutions and Party Cohesion in the Russian Duma', Journal of Politics, 60 (1998), 417-39;
18. and Scott Morgenstern, Patterns of Legislative Politics: Roll Call Voting in Latin America and the United States (New York: Cambridge University Press, 2004). This is a very small sample; there are many others.
19. Occasionally a scholar will remind us that cohesion has never been grounded theoretically, but none have attempted such a grounding. For example, Aage R. Clausen, 'The Measurement of Legislative Group Behavior', Midwest Journal of Political Science, 11 (1967), 212-24, notes that scores lack an underlying model of individual behaviour
20. and Lee F. Anderson, Meredith W. Watts Jr and Allen R. Wilcox, Legislative Roll-Call Analysis (Evanston, Ill.: Northwestern University Press, 1966) caution against blind use of traditional statistical methods to analyse cohesion scores. But no scholar I am aware of has investigated Rice cohesion scores' statistical properties. Interestingly enough, a number of scholars nearly stumbled upon the problem and solution.
21. Arend Lijpardt, 'The Analysis of Bloc Voting in the General Assembly: A Critique and a Proposal', American Political Science Review, 57 (1963), 902-17, p. 908, reports that a number of unanimity-based scores inflate small bloc values, but then erroneously concludes that the Rice cohesion score is free of this defect.
22. Steven J. Brams and Michael K. O'Leary, 'An Axiomatic Model of Voting Bodies', American Political Science Review, 64 (1970), 449-70, advocate a measure similar to mine, but with an adjustment that actually magnifies small party inflation - increasing bias. Other scholars propose and examine cohesion measures' properties, but consistently in descriptive terms, without an underlying model of legislative behaviour.
23. For example, studying the Swiss Parliament, Prisca Lanfranchi and Ruth Luthi, 'Cohesion of Party Groups and Interparty Conflict in the Swiss Parliament: Roll Call Voting in the National Council', in Shawn Bowler, David M. Farrell and Richard S. Katz, eds, Party Discipline and Parliamentary Government (Columbus: Ohio State University Press, 1999), pp. 99-120, at p. 108, find that 'the Rice Index is in most cases higher for non-governmental party groups than for the three "bourgeois" governmental parties (Radicals, Christian Democrats, People's Party).' Coincidentally, the non-governmental parties are also smaller than most governmental parties.
24. Rapio Raunio, 'The Challenge of Diversity: Party Cohesion in the European Parliament', in S. Bowler, D. M. Farrell and R. S. Katz, eds, Party Discipline and Parliamentary Government (Columbus: Ohio State University Press, 1999), pp. 189-207, p. 199, examines cohesion in the parliament of the European Union. He observed that The high cohesion of the EDG, the ER, EUL, and the Left Unity (LU) result from these groups' rather homogeneous character.' Again, these four parties also happen to be the smallest in the European Union's National Council.
25. Scott Mainwaring and Anibal Perez Liñán, 'Party Discipline in the Brazilian Constitutional Congress', Legislative Studies Quarterly, 12 (1997), 453-83, study party cohesion in Brazil's Constituent Assembly, finding that the biggest parties are less disciplined than small parties. In the United States,
26. Roxanne L. Gile and Charles E. Jones, 'Congressional Racial Solidarity: Exploring Congressional Black Caucus Voting Cohesion, 1971-1990', Journal of Black Studies, 25 (1995), 622-41, compare cohesion of the Congressional Black Caucus (CBC) with that of Northern and Southern Democrats. They find that the CBC is the most cohesive of the three. It is also easily the smallest. In general, scholars attribute these findings to the 'homogeneity' of small parties, but have not offered any theoretical explanation for small parties' consistently high cohesion.
27. He describes the interpretation of cohesion scores as follows: 'Are the Republican members in a state senate more alike in their votes than are the members of the senate generally? If so, it may be inferred that they are more like-minded and the Republican group may be called more cohesive than the senate as a whole' (Rice, Quantitative Methods in Political Science, p. 208).
28. Anderson et al., Legislative Roll-Call Analysis.
29. Reported scores usually represent the average cohesion score for a party across all roll-call votes cast during a year or legislative term. See Anderson et al., Legislative Roll-Call Analysis, for a discussion of methods for averaging across multiple roll-call votes.
30. Generalizing to n odd just requires changing the summation range's maximum value for the second term in (4) from k = n/2 to k = (n - 1)/2.
31. The algebra is in Appendix A.
32. Keith T. Poole and Howard Rosenthal, Congress: A Political-Economic History of Roll Call Voting (New York: Oxford University Press, 1997);
33. Gary W. Cox and Keith T. Poole, 'Measuring Partisanship in Roll-Call Voting: The U.S. House of Representatives, 1877-1999', American Journal of Political Science, 46 (2002), 477-89;
34. James Snyder and Timothy Groseclose, 'Estimating Party Influence on Roll-Call Voting', American Journal of Political Science, 44 (2000), 193-211;
35. Nolan McCarty, Keith Poole and Howard Rosenthal, 'The Hunt for Party Discipline in Congress', American Political Science Review, 95 (2001), 673-88;
36. John Londregan, 'Appointment, Reelection and Autonomy in the Senate of Chile', in Scott Morgenstern and Benito Nacif, eds, Legislative Politics in Latin America (New York: Cambridge University Press, 2002), pp. 341-76;
37. Simon Jackman, 'Multidimensional Analysis of Roll Call Data via Bayesian Simulation: Identification, Estimation, and Model Checking', Political Analysis, 9 (2000), 227-41;
38. Jeff Lewis and Keith Poole, 'Measuring Bias and Uncertainty in Ideal Point Estimates via the Parametric Bootstrap', Political Analysis, 12 (2004), 105-27.
39. Cox and Poole, 'Measuring Partisanship in Roll-Call Voting:', p. 479.
40. Brian Crisp, Kris Kanthak and Jennie Leijonhufvud, 'A Non-Spatial Understanding of Position-Taking and Vote Seeking: Cosponsorship as "Currency" for Purchasing Electoral Support', American Political Science Review, 98 (2004), 703-16.
41. Additional details on the simulations are provided in the Appendices.
42. See, for example, John M. Carey, 'Political Institutions, Competing Principals, and Party Unity in Legislative Voting' (unpublished paper, Dartmouth College, 2001).
43. ijr).
44. I explored several methods for subtracting an inflation factor. All but one approach failed to eliminate the relationship between party size and cohesion score. The approach that worked required assuming that p is constant across all roll-call votes - i.e., on all votes, legislators face exactly the same net pressures and positions. This assumption would be completely unrealistic for all legislatures I am familiar with.
45. Gile and Jones, 'Congressional Racial Solidarity', p. 638.
46. Scott Mainwaring, 'Multipartism, Robust Federalism, and Presidentialism in Brazil', in Scott Mainwaring and Matthew S. Shugart, eds, Presidentialism and Democracy in Latin America (New York: Cambridge University Press, 1997), pp. 55-109;
47. Barry Ames, The Deadlock of Democracy in Brazil (Ann Arbor: The University of Michigan Press, 2001);
48. Octavio Amorim Neto and Fabiano Santos, 'The Executive Connection: Presidentially Defined Factions and Party Discipline in Brazil', Party Politics, 7 (2001), 213-34.
49. I excluded legislators that were not in a party, and a small party that only voted on two bills.
50. Mildred L. Amer, Black Members of the United States Congress: 1789-2001 (Washington, D.C.: Congressional Research Service, The Library of Congress, 2001).
51. Argelina Figueiredo and Fernando Limongi, 'Votações nominais na Câmara dos Deputados - 1989-1999', in dataset from Banco de Dados Legislativos Cebrap, 2000.
52. A beta with parameters (1,1) is effectively a uniform distribution. I experimented with other parameters. Results were unchanged for any symmetric distribution (α = β). Cohesion scores did increase for any skewed distribution, but the small party inflation persisted.