There’s a new paper by Gethin, Martínez-Toledano, and Piketty in the QJE that’s worth discussing, entitled “Brahmin Left versus Merchant right: Changing Political Cleavages in 21 Western Democracies, 1948-2020.” The paper uses a comprehensive electoral dataset to study class voting in 21 democracies, between 1948 and 2020 (and it’s worth noting that this paper is a descendant of Piketty’s book, Capital in the Twenty First Century). TLDR; the paper finds that over time, higher-educated voters are voting for the Left, while high income voters still vote for the Right; this suggests the rise of new political cleavages and the changes to traditional class based voting.
It’s making waves, however, because it seems to be the latest example of a paper in one field that has ‘discovered’ something that another field has known for decades. Even if the scale or breadth of the data is impressive, this is worth discussing, for a number of reasons.
Citations, Citations, Citations
First, engaged citation is important. One flaw of the QJE paper is that while political scientists are cited, it’s in a superficial way — think cursory lists of citations, instead of discussing the details of prior work. Now, one might argue that it’s great to see political scientists cited in a top Econ journal — the attempt at interdisciplinary dialogue is there! This is true, and I hope a sign of progress. But what’s tough here is that the topic is extensively studied in political science and other fields (such that the ultimate findings are not new).
And while canonical work in political science (eg, Kitschelt and Inghehart) is cited, there’s a large literature of highly relevant and more recent papers missing. The study of electoral fortunes across country and time using micro-level data, including elections and manifestos, is a cornerstone of political science research. So is the decline of class voting, the strategies of Left parties, and individual-level determinants of voting such as education and income — for readers interested in the topic, see Benedetto, Hix, and Mastrorocco’s 2020 APSR piece, entitled “The Rise and Fall of Social Democracy, 1918-2017”, or work such as Abou-Chadi and Wagner (2019); Beramendi and Anderson (2011); Beramendi, Häusermann, Kitschelt, Kriesi (2015), etc.
The fact that working class voters and middle class voters have switched their alignment over time has also been established by prior work — not cited. In one example, Gingrich and Häusermann (2015) show this electoral substitution in the figure below. According to Google, this paper has been cited by 276, so far from obscure.
Second, I find it strange that the QJE paper almost ignores a paper written by Tarik Abou-Chadi and Simon Hix, in the February 2021 issue of the British Journal of Sociology. Abou-Chadi and Hix are are actually responding to Part Four of Thomas Piketty’s Capital and Ideology. Among other things, they argue a major flaw with the book is that it focuses on the traditional Left versus Right divide, and misses an important factor in electoral politics in advanced democracies — the growing fragmentation of party systems. The new QJE article did not make this same mistake, but doesn’t really mention the thoughtful critique by Abou-Chadi and Hix. It’s possible the QJE authors came to the conclusion about fragmentation by other means, fair (and it’s worth noting I have not consulted with either team of authors, when writing this post). But it’s strange that they don’t engage with this directly relevant article.
(Also my lens for this post is that of a political scientist — political sociologists and historians also have much to say on the growing divide across voting groups.)
Interdisciplinarians
Besides annoying political scientists on Twitter, what does this teach us?
At Broadstreet, we spend a lot of time thinking about the interdisciplinary nature of historical political economy. We work on topics that often cross disciplines — it is entirely possible for scholars in economics, history, sociology, and political science to be working on similar things. At the end of the day, no field “owns” topics (though some are clearly identified with some disciplines more than others). Different scholars could be using the same primary sources, similar data constructions, and asking related research questions (maybe using different methods).
It’s possible that “ships pass in the night,” in that scholars are working simultaneously on the same topics and might not realize there is relevant work that needs to be cited (this is one reason for peer review). But I don’t *think* that’s what happened here (and a similar, edited volume seems to do the same). And in the age of Google Scholar, Twitter, and connectedpapers.com, this DOES NOT have to be the case.
This is an ongoing process — Angrist et al (2020) provide some empirical data to show how the social sciences relate to each other in citation practices, and economics is much less interdisciplinary. Kevin Munger has a blogpost that discusses this and offers some interesting insight, as well.
In conclusion, a fundamental part of research is knowing what has gone before, and spending significant time reading and learning from what has come before — and that includes acknowledging and engaging with the prior work of other fields.