It’s pretty clear that people’s answers to political questions which are not obviously related correlate with each other. People who believe in lower taxes are more likely to not believe in easily accessible abortion, although of course there are exceptions. But what is the structure of the relationships between these political beliefs? Is there a a single left-right axis or an “economic” axis and a “cultural” axis? One way to work this out is to get a battery of political questions, have a bunch of subjects answer them and then use factor analysis.

(Factor analysis is a method of statistical analysis which aims to capture the relationships between observed variables by positing a smaller number of unobserved factors which best explain those relationships.)

I applied factor analysis to a battery of questions asked by Pew research -questions in appendix 1-. When I did so, there was a pretty clear one factor solution. For those who know a little bit about factor analysis I’ve attached the scree plot at the very end of the document.

Notably although the scree-plot pretty clearly supports a 1 factor analysis, that factor only explains ~20% of the variance in all questions, suggesting that there’s a lot of question by question variance. In this sample at least, people vary along a unidimensional spectrum, but their answers to individual questions are still sort of random, only very partly explained by trends in their answers to other questions.

The results are intriguing, because as far as I can tell there’s an emerging consensus in the political science literature that a dimensional approach is better than a one dimensional approach for describing ideology. The discrepancy between my results and the results of the political science experts could be artefact of the sample, the questions I choose to look at or the statistical methodology I used. While I’d tend to back the emerging expert consensus over my own results, it’s interesting that we can find a one factor solution on at least some prima-facie reasonable specifications.

To further test whether economic and cultural politics were separate dimension in this sample, with the available battery of questions, I took a battery of economic questions and ran a factor analysis on them, took a battery of social questions and ran a factor analysis on them, established that both had a one factor solution and then correlated the factor loading from the economic questions with the factor loading from the social questions. Effectively I ran a correlation of a measure of economic beliefs against a measure of cultural politics beliefs. Despite having only a very small number of questions in each battery (5 each, almost all yes/no), the underlying factor of economic progressivism correlated with the underlying factor of social progressivism .56, one imagines that the real correlation corrected for the unreliability and limited scope of the economic and cultural politics measures is much higher.

Notably in the European social survey data I looked at, while I wasn’t able to do a factor analysis per se, there was some preliminary evidence that a solution with at least two factors. Suppose this were a real difference between the US and Europe, it might be due to the difference in electoral systems- a winner take all system which encourages exactly two parties for the US, and many parties being represented in parliament for most European countries. Perhaps Europeans can afford to vary along multiple dimensions, while Americans are squeezed into only one. If so this is interesting, and might give us a window into the way in which political necessities can influence ideology formation in ordinary people. Again, assuming any of this is real, it would be interesting to study the mechanism in more detail.

Appendix: Questions & methods- Factor loading in bold

N=1034

Participants who answered ‘Don’t know’ or refused to answer any of these questions were excluded.

The data comes from Pew research. Not all participants were asked all questions so I had to be picky about which questions I included to make sure I had a large enough sample. I tried to pick a good mix of questions from all over politics, with a healthy balance of directly economic and non directly economic topics.

Q.A126a Should health insurance [READ AND RANDOMIZE]? .321

Q.A128 Do you strongly favor, favor, oppose, or strongly oppose allowing gays and lesbians to marry legally? .648

Q.A129 Do you think abortion should be [READ IN ORDER TO RANDOM HALF OF SAMPLE, IN REVERSE ORDER TO OTHER HALF OF SAMPLE]? .548

Q.25a. Government is almost always wasteful and inefficient [OR] Government often does a better job than people give it credit for -.311

Q.25b Government regulation of business is necessary to protect the public interest [OR] Government regulation of business usually does more harm than good .444

Q.25c Poor people today have it easy because they can get government benefits without doing anything in return [OR] Poor people have hard lives because government benefits don’t go far enough to help them live decently -.435

Q.25d. The government should do more to help needy Americans, even if it means going deeper into debt [OR] The government today can’t afford to do much more to help the needy .379

Q.25f. Racial discrimination is the main reason why many black people can’t get ahead these days [OR] Blacks who can’t get ahead in this country are mostly responsible for their own condition .586

Q.25g. Immigrants today strengthen our country because of their hard work and talents [OR] Immigrants today are a burden on our country because they take our jobs, housing and health care .546

Q.25i. The best way to ensure peace is through military strength [OR] Good diplomacy is the best way to ensure peace -.505

Q.25k. Most people who want to get ahead can make it if they’re willing to work hard [OR] Hard work and determination are no guarantee of success for most people -.401

Q.25n. Business corporations make too much profit [OR] Most corporations make a fair and reasonable amount of profit .222

Q.50r Stricter environmental laws and regulations cost too many jobs and hurt the economy [OR] Stricter environmental laws and regulations are worth the cost -.318

Q.50u. Homosexuality should be accepted by society [OR] Homosexuality should be discouraged by society .560

Q.50ee. It’s best for the future of our country to be active in world affairs [OR] We should pay less attention to problems overseas and concentrate on problems here at home .511

Q.50hh. Our country has made the changes needed to give blacks equal rights with whites [OR] Our country needs to continue making changes to give blacks equal rights with whites -.445