Economists Work in Communities, and this Shapes the Incentives for Research

by Carlo D’Ippoliti

Other social scientists accuse economists of picturing human beings as anti-social egoistic individuals – and of behaving themselves that way. In a new working paper summarizing a recently concluded Rebuilding Macroeconomics project, with some colleagues we show that this is definitely not the case.

We collected data on virtually all economists affiliated to UK universities: on their studies, publications, and career in the last four decades, including (for 735 of them, of which we could identify a user account) what they tweeted or retweeted since 2010. We focused on their citations in scientific papers: these may be seen as the currency of academia, because the chances of being hired and promoted, of seeing one’s work publicised and discussed, or one’s research projects financed, and more in general reputation and standing within the profession, all depend to some extent on one’s citation counts.

Analysing this crucial form of interaction among UK-based scholars, we found that economists do care about their friends and colleagues. For example, in their works they cite recent coauthors between three and four times more than someone they are not related with. Similarly, economists sharing the same “spiritual home”, that is, those who graduated in the same place, exchange 30-40% more citations than the others; and each year in which two academics have been based in the same institutions, increases citations between them by another 50%.

Of course, this is not to say that the scientific content of what economists write is irrelevant in shaping their citations. Similarity of topics (identified by JEL codes) and scientific proximity (measured by having cited the same works in the past, or having written in the same journals) are relevant indeed. But so is proximity in the ideological sphere: sharing links from different (politically connotated) web sources reduces citations between two economists by around 25%.

On the whole, our analysis shows that both scientific and personal proximity are relevant in determining citations in the economic debate, and possibly even more so in the macroeconomic debate, where scientific proximity seems less relevant, and professional proximity more relevant, than in other fields of economics.

There are two main implications of these findings. First, citations depend on many things, including one’s position within the economics profession, or one’s professional and personal background. The discipline should thus rely less on citation counts to distribute honour and resources within the profession. In this sense, it is worrying that – although formally asked to proceed by peer review, economists have often been found to evaluate research works on the basis of journal-level citation indexes, including in the past round of the UK Research Excellence Framework. Reading the single papers is surely more demanding, but for the moment there doesn’t seem to be an alternative, if one wants to assess the quality of a research or a university department.

Second, until economists are assessed and rewarded on the basis of citation counts, especially younger economists and those in most vulnerable positions (for example those on precarious jobs) will have strong incentives to join as many and as large communities as they can, in order to try and attract more citations. This implies studying the most popular topics (to join the larger scientific communities) instead of what the single researchers thinks is important, or competing to graduate in the larger institutions (to join the larger professional communities) instead of where one thinks interesting people can be found, who could act as teachers and mentors. It may even imply adapting to the general political views among our colleagues, or at least hiding our own’s views from the social media, when they are different from the mainstream.

As the main scientific academies have noted, all this cannot but stifle innovation and creativity in our science.

Examples of scientific communities (citations: left) and professional communities (scholars who graduated in the same institution, right) among UK academic economists