Figure 1: Decreasing intra-party dissent Notes: Vote data was gathered from the Hansards provided at info.mzalendo.com. The y-axis indicates the mean rate of dissenting votes within each party. Thus, 0 indicates no dissent, and .3 indicates that on average 30 percent of MPs dissented from their party majority on roll call votes. Using probit models with as a binary outcome variable, and 9th, 10th, and dissent 11th parliament dummies as key variables, we can control for more variables than the bar graph in figure 1 allows. Table 2 shows the estimates of four different probit models. In model 1 none of the control variables are included. In model 2, two MP-level dummies are controlled for: party and county. In model 3 two legislation-level dummies are controlled for: the legislative procedure (e.g. clause, second reading, adoption of report), and the substantive issue of the motion (e.g. electoral, constitutional, budgetary). In model 4, all four control variables are included. I also cluster standard errors by legislative motion for each model. Table 2: Probit models of MP dissenting votes Variable Model 1 Model 2 Model 3 Model 4 -.5043** -.3940† -.1796 .0046 9th to 10th parl (.1859) (.2036) (.1385) (.1527) -.4925* -.6758** -.5265* -.7387* 10th to 11th parl (.2297) (.2461) (.2199) (.3074) Party dummies Included Included — — County dummies Included Included — — Issue dummies Included Included — — Procedure Included Included — — dummies -.9402*** -6.465*** -.6385* -6.392*** Constant (.1312) (.6150) (.3137) (.7360) Psuedo-R2 .0599 .0933 .1472 .1838
Figure 1: Decreasing intra-party dissent Notes: Vote data was gathered from the Hansards provided at info.mzalendo.com. The y-axis indicates the mean rate of dissenting votes within each party. Thus, 0 indicates no dissent, and .3 indicates that on average 30 percent of MPs dissented from their party majority on roll call votes. Using probit models with dissent as a binary outcome variable, and 9th, 10th, and 11th parliament dummies as key variables, we can control for more variables than the bar graph in figure 1 allows. Table 2 shows the estimates of four different probit models. In model 1 none of the control variables are included. In model 2, two MP-level dummies are controlled for: party and county. In model 3 two legislation-level dummies are controlled for: the legislative procedure (e.g. clause, second reading, adoption of report), and the substantive issue of the motion (e.g. electoral, constitutional, budgetary). In model 4, all four control variables are included. I also cluster standard errors by legislative motion for each model. Table 2: Probit models of MP dissenting votes Variable Model 1 Model 2 Model 3 Model 4 9th to 10th parl -.5043** (.1859) -.3940† (.2036) -.1796 (.1385) .0046 (.1527) 10th to 11th parl -.4925* (.2297) -.6758** (.2461) -.5265* (.2199) -.7387* (.3074) Party dummies — Included — Included County dummies — Included — Included Issue dummies — — Included Included Procedure dummies — — Included Included Constant -.9402*** (.1312) -6.465*** (.6150) -.6385* (.3137) -6.392*** (.7360) Psuedo-R2 .0599 .0933 .1472 .1838