The Ideological Consistency Scale

万得福

Appendix A: The Ideological Consistency Scale
Throughout this report we utilize a scale composed of 10 questions asked on Pew Research Center surveys going back to 1994 to gauge the extent to which people offer mostly liberal or mostly conservative views across a range of political value dimensions. In short, while there is no ex-ante reason for people’s views on diverse issues such as the social safety net, homosexuality and military strength to correlate, these views have a traditional “left/right” association, and the scale measures this growing correlation over time.

[size=1.6em]

[size=1.6em]The individual questions in the scale are shown here. The topline shows the long term trends on these items, and Section 1 tracks the partisan divides on each question since 1994.

[size=1.6em]Individual questions were recoded as follows: “-1” for a liberal response, “+1” for a conservative response, “0” for other (don’t know/refused/volunteered) responses. As a result, scores on the full scale range from -10 (liberal responses to all 10 questions) to +10 (conservative responses to all 10 questions). For analytical purposes, respondents are grouped into one of five categories, which are used throughout the report, as follows:

• Consistently conservative (+7 to +10)
• Mostly conservative (+3 to +6)
• Mixed (-2 to +2)
• Mostly liberal (-6 to -3)
• Consistently liberal (-10 to -7)
  

[size=1.6em]To put these figures in perspective, a respondent offering five liberal and five conservative views, or six of one and four of the other, would be considered as having “mixed” ideological views. Someone offering seven conservative and three liberal responses, or eight and two, would be considered “mostly conservative.” And any respondents offering nine conservative and one liberal response, or all ten conservative, would be considered “consistently conservative.” Since some people do not answer every question, other combinations are possible.

[size=1.6em]The graphics in the ideological consistency section and the engagement section use the full set of points on the scale (note that graphics in the ideological consistency section are smoothed by showing the average of two consecutive points on the scale).

[size=1.6em]Any ideological index has its limitations because defining what it means to be liberal and conservative is inherently controversial. As we have illustrated elsewhere, American political thinking is multidimensional, and any effort to “flatten” ideology to a single left/right dimension may miss this rich texture.

[size=1.6em]But our purpose here is to study the concept of ideological “consistency” – or the share of Americans who hold liberal or conservative views across a range of values dimensions; this is also sometimes referred to as “ideological constraint” or “ideological sorting” by political scientists and other researchers.

[size=1.6em]Because the focus is on change over time, we are limited to a set of questions that were invented 20 years ago, and this creates imperfections. For example, the elements of the index do not cover more recent value divides, such as surveillance or terrorism.

[size=1.6em]In addition, while the range of the scale (from -10, all liberal responses, to +10, all conservative responses) remains the same throughout the period of study, the “center” of the American public does shift. For instance, in 2014 the mean on the scale is -0.6, slightly to the left; in 1994 the mean score was slightly to the right (+0.6). To a large extent, this shift reflects an overall societal shift to the left on two issues: homosexuality and immigration.

[size=1.6em]This overall shift does not necessarily mean that the average American is more liberal than conservative because the mean is now less than zero. But it does mean that people on the liberal end of the scale are now somewhat closer to the center of the scale than are those at the conservative end. As a result, the relative sizes of the “consistently liberal” and “consistently conservative” groups are not strictly comparable. That is, because of the scale’s construction, we would not definitively conclude that there are more consistent liberals (12%) than consistent conservatives (9%) today. Yet the changes over time—e.g., the overall increase in the proportion who are consistently liberal or conservative—and the differences in attitudes and behaviors across groups, are robust even when alternative definitions that account for the scaling differences are used.

kaleege

Appendix B: Why We Include Leaners With Partisans

[size=1.6em]Throughout this report, the analysis of partisan attitudes combines both those who identify with and those who lean toward the parties. In many respects, those who lean toward the parties—even if they identify as independent—have attitudes and behaviors that are very similar to those of partisans. That most leaners are “closet partisans” has been observed by many political scientists (see here and here for a few recent examples of this discussion). And we have remarked on this in prior Pew Research Center studies, including in our 2012 Values poll—see the end of section one of the Values report for a discussion.

[size=1.6em]And this pattern is again evident when it comes to the two dimensions of polarization discussed in this report: ideological consistency and partisan acrimony.

[size=1.6em]

[size=1.6em]On the first, discussed here, leaners’ ideological positions largely overlap those of partisans. And as Republicans have become more conservative, and Democrats more liberal, leaners have moved along with them.

[size=1.6em]Over the last two decades, Republican leaners have been, on average, just slightly less conservative than Republicans overall. For instance, today, 57% of Republican identifiers and 47% of Republican leaners are consistently or mostly conservative. By contrast, just 5% of Democratic leaners are mostly or consistently conservative (see Appendix A for a discussion of the ideological consistency scale).

[size=1.6em]

[size=1.6em]The positions of those who identify as Democrats and those who lean toward the Democratic Party are nearly identical over this time period: 57% of Democrats and 54% of Democratic leaners are consistently or mostly liberal today. When the two groups did diverge in 2004, Democratic leaners were somewhat more likely than Democrats to be to the left of center.

[size=1.6em]And the dislike of the opposing party discussed here is almost as acute among leaners as partisans. Today, nearly as many Republican leaners (40%) as Republicans (46%) express very unfavorable opinions of the Democratic Party, and the steep growth in deeply negative views is seen in both groups.

[size=1.6em]On the left, Democratic leaners are somewhat less likely than Democratic identifiers to hold strongly negative views of Republicans (42% of Democrats and 30% of Democratic leaners have a very unfavorable opinion of the GOP). Still, the overall growth in antipathy is just as pronounced among leaners as among Democrats.

[size=1.6em]

[size=1.6em]Overall, it would have been possible to combine these two groups of “leaners” into a single “independent” category to contrast with Republicans and Democrats (that line is plotted in the middle of the above graphics). But combining these two dramatically different groups would be misleading; these are two groups that have little in common with each other, and far more in common with self-identified partisans.