Wednesday, 30 May 2018

It seems it's better to publish economics papers with U.S. data

This post follows on from yesterday's post about the length of article titles, which showed a strong negative correlation between title length and research quality (so papers with shorter titles were more likely to be published in better journals, and attracted more citations). There are, of course, a lot of other factors that affect where journal articles get published. One gripe for many researchers outside the U.S. or the U.K. is how hard it is to get published in top journals using data from outside the U.S. or the U.K. Until relatively recently, that gripe was based on purely anecdotal evidence. However, a 2013 article by Jishnu Das, Quy-Toan Do, Karen Shaines (all from the World Bank), and Sowmya Srikant (FI Consulting), published in the Journal of Development Economics (ungated version here) provides some empirical evidence on this.

Das et al. use data on over 76,000 papers published in 202 economics journals over the period from 1985 to 2005, and the disparity in data sources for published economics papers is clear:
Over the 20 year span of the data, there were 4 empirical economics papers on Burundi, 9 on Cambodia and 27 on Mali. This compares to the 37,000 or so empirical economics papers published on the U.S. over the same time-period. This variation is also reflected among the highly selective top-tier general interest journals (henceforth top-tier journals) of the economics profession (American Economic Review, Econometrica, The Journal of Political Economy, The Quarterly Journal of Economics and The Review of Economic Studies). American Economic Review has published one paper on India (on average) every 2 years and one paper on Thailand every 20 years. The first-tier journals together published 39 papers on India, 65 papers on China, and 34 papers on all of Sub-Saharan Africa. This compares to 2383 papers on the U.S. over the same time period.
They then go on to show about 75 percent of the cross-country variation in the geographical focus of research is explained by GDP per capita and by population. Countries that have higher GDP are more likely to be the focus of research. This is a disappointing result if you are interested in developing countries (as the authors of the paper clearly are). Surprisingly though:
...the U.S. is not an outlier in the volume of research that is produced on it... the volume of research for the U.S. lies well within the predicted confidence interval and excluding the U.S. leads to the same coefficient estimates as its inclusion. In other words, a lot more is produced on the U.S. because it is rich and it is big; the natural comparator for the U.S. would be all of Europe and here, the volume of research is very similar.
However, when it comes to the elite journals, the U.S. is a clear outlier:
The difference between the U.S. and the rest of the world is substantial — 6.5% of all papers published on the U.S. are in the top tier journals relative to 1.8% of papers from other countries.
For comparative purposes, over their 20-year period there were 2,383 publications on the U.S. published in the top five economics journals, and one on New Zealand (yes, you read that right, just one - I don't know which article it was, sorry).

So, is this discrimination against non-U.S. research? Perhaps. Or, it could be as simple as the U.S. having a greater density of top-quality researchers, who are more likely to publish in top-quality journals, and who, because they are located in the U.S., have readier access to U.S. data. Or, perhaps the quality of U.S. data is higher. Das et al. point out that data quality has a superstar effect to it (similar to the superstar effects in the labour market that I have written about before):
Researchers converge on the “best” dataset even if it is 1% better than other data available, and the initial work creates a focal point for further research with the same data.
Again, like the paper I discussed yesterday, there isn't necessarily a causal interpretation to these results (doing research on the U.S. doesn't necessarily cause papers to be accepted into top journals). But it is disappointing, particularly given the quality of linked administrative data that we have in New Zealand through the Integrated Data Infrastructure, which (I think) should be attractive for publication in top journals.

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