This week in research #118

Here's what caught my eye in research over the past week (a quiet week, following last week's bumper edition):

• Rubenstein and Stephenson assess the effect of Taylor Swift’s relationship with Travis Kelce on the Kansas City Chiefs’ television audience, and find that viewership increases by about one-third beginning with Swift’s first time attending a Chiefs’ game
• Bussoli and Fattobene (open access) find that Financial Graph Literacy is lower among older adults, those with less education, and lower-income groups, and is significantly associated with a greater likelihood of engaging in proactive financial behaviours such as saving, investing, budgeting, and using digital financial tools

How the 'travelling Pope' affected international trade

Pope John Paul II was known as 'the travelling Pope' because of the large number of international trips ('pastoral visits') he undertook (more than 100 during his reign from 1979 to 2004). He also had a huge following, as you might expect as the leader of the Catholic Church, but the advent of television meant that the public could follow his travels in a much closer way than ever before. And, through his pastoral visits and his following, he exposed Catholics the world over to new places they would otherwise not have seen or, in some cases, even heard of. What effects did that exposure have?

That is essentially the question addressed in this recent article by Alexander Popov (European Central Bank), published in the Economic Journal (ungated earlier version here). Popov focuses on the impact of the Pope's visits on exports from the visited country, and especially exports to Catholic countries. He employs an event study design - looking at how exports changed between the time before and the time after the Pope's first visit to a country, while controlling for GDP growth, population, the US dollar real exchange rate, and the extent of trade liberalisation and democracy. The key results are summarised in Figure 2(a) from the paper:

The figure shows how exports evolve before and after the Pope's visit. Beforehand, there isn't much evidence of a trend (notice that the red line hovers around zero). However, after the Pope's visit, exports increase (the red line is clearly above zero and trending upwards), and the effect is substantial. Popov notes that:

...the point estimate on Year 3 after the pope’s visit to a country is 0.1152, which implies that exports to the rest of the world are higher by 12.2%, relative to the year of the visit.

And the effects are even larger for exports to countries with larger Catholic populations. Specifically:

...exports to a trading partner with 54.3% (75th percentile), relative to a trading partner with 1.1% (25th percentile) Catholics in the population were higher by between 16.5% and 36.9% during years 1 to 5 after a visit by the pope.

Clearly, Catholics were paying attention to where the Pope was visiting. Popov then asks the obvious question: what explains this effect? He examines three hypotheses:

The first one is that during a foreign visit, the pope explicitly encourages Catholics around the world to engage with the host country on economic terms. I analyse 633 speeches given during the pope’s 130 first visits and I find rare occasions when he mentions words like ‘trade’, ‘economic’ or ‘globalisation’.

So, the Pope wasn't explicitly telling Catholics to buy more goods from the countries he was visiting. Then:

The second hypothesis is that, by simply visiting a country, the pope raises its profile, or ‘puts it on the map’ for the global Catholic family, especially if Catholics around the world are for cultural or economic reasons less connected with the visited country. I find that the effect on exports of a pastoral visit to a country is stronger if this country is relatively poor and if it has relatively fewer Catholics and relatively weaker bilateral trade links with the partner country. The third hypothesis is that Catholics around the world are simply buying souvenirs to commemorate the pope’s visit. I analyse data on bilateral trade at the product level, for ten different sectors, and I find that after a pastoral visit, the increase in exports I detect takes place in half of them.

So, the third hypothesis (souvenirs) doesn't have much support. Popov concludes that the second hypothesis shows the likely driver of the increase in exports. This evidence is consistent with the Pope raising the profile of the countries he visited, and those countries benefiting from their higher profile among Catholics in the form of higher exports, especially to Catholic countries.

What makes this paper interesting in an economic sense is that it suggests trade flows don't just depend on prices, trade policy, and distance. They also depend on visibility, familiarity, and the ways that cultural influence can affect economic outcomes. Pope John Paul II's visits appear to have increased visibility and familiarity, which may in turn have boosted trade. The 'travelling Pope' may have also been the 'trade-promoting Pope'.

Seven decades of change in the demographics and research styles of top economics research

Back in 2013, Daniel Hamermesh (University of Texas at Austin) published this article in the Journal of Economic Literature (ungated earlier version here), which summarised changes in the demographics and research styles of top economics research, based on articles published between 1963 and 2011 in three top journals: the American Economic Review (AER), the Journal of Political Economy (JPE), and the Quarterly Journal of Economics (QJE). A new update last year (open access) from Hamermesh extends the analysis to include articles up to 2024.

In terms of demographics, the trends show a continuation and in terms of gender, Hamermesh notes that:

The progression that occurred from the 1960s and 1970s, when only a minute fraction of authors were women, to the early twenty-first century has, if anything, accelerated.

This will be welcome news, given the persistent gender gap in economics (see this post and the links at the end of it). It likely reflects the changing demographics of young economists, with a growing proportion of the young 'stars' in economics being women (and noting that it is young stars who often get published in the top journals that Hamermesh is considering).

In terms of the age structure of authors, Hamermesh reports that:

The changes from 2011 to 2024 continued those that started in the 1980s, but the rate of change has not accelerated. Indeed, most noticeable from 2011 to 2024 was a continuing sharp and statistically significant drop in the representation of the youngest group (and a nearly equal sharp rise among those 36–50)...

...the average age of authorship has increased steadily since 1973. 

Can I change my comment above about the young stars in economics? The increasing median age of authors in top journals seems to be a general trend across academia. Hamermesh then turns to research 'style', documenting a continued dramatic rise in the proportion of articles in those journals that are co-authored:

There were no four-authored papers as recently as 1983; today they account for 17 percent of articles. There were no papers with more than four authors in 2003; today nearly 12 percent of articles have five or more authors (with five articles written by six authors each and one by seven authors). Obversely, sole-authored papers are now quite scarce; and even two-authored papers today only account for slightly more than one-fourth of all articles (compared to a majority as recently as 2003).

Unsurprisingly, the increase in the number of co-authored articles means that the age diversity of author collaborations has increased over time as well. In terms of the types of research, he reports that:

The big changes are the continuing rise in empirical work based on original non-laboratory data and the rapid and even accelerating increase in experimental work. Today these two methods, which both involve collecting original data, account for over half of all published papers, compared to less than 4 percent four decades ago...

These trends are not all unrelated, of course. Experimental research, and the increasing use of large datasets, typically both require larger research teams. They also often require more detailed methods, which may involve both larger teams, and more experienced researchers. Larger teams might be more likely to include female team members. And larger teams often need someone to lead and coordinate all of the team members, and those leaders tend to be more experienced (and older) academics. So, it would not surprise me, if more detailed analysis was conducted, to see that the trends are interconnected.

Now, the interesting thing will be what happens going forward, given the increasing use of generative AI in research (see here, for example). Since generative AI can now do a lot of the work that research assistants and early career researchers previously did, will the trend towards larger research teams be reversed? How will that interact with the gender gap in research (given that the age of female economists skews younger at the moment). And how will it affect the age distribution of researchers (given that men, and younger people, are somewhat more likely to use generative AI). I'll be looking forward to Hamermesh's next update. Hopefully, we don't have to wait another 12 years.

[HT: Marginal Revolution, last year]

Changing their minds could be a good thing for economists

People don't like to change their minds. This may partly be an expression of loss aversion - we really want to avoid losses, including the loss of an idea that we previously thought was true. This leads to status quo bias - we prefer not to change things, and keep them the same, because changing things entails a loss. But what if changing our minds could make us better off? Would we be so reluctant to do so?

This 2025 paper by Matt Knepper (University of Georgia) and Brian Wheaton (UCLA) suggests that economists, at least, should not be afraid to change their minds, because doing so increases the number of citations to their research. Knepper and Wheaton investigate authors who undergo an 'ideological reversal' - previously publishing research that could be considered right-wing, before switching and publishing a paper that draws a left-wing-consistent conclusion, or the reverse (switching from left-wing to right-wing). Their main data source is every economics paper ever published in the top 100 economics journals indexed in Web of Science - some 200,000 articles. They also have a narrower dataset of papers referenced in meta-analyses on policy topics, including:

...the minimum wage, the economics of unions, the taxable income elasticity, the fiscal multiplier, intergenerational transfers, trade and productivity, trade and domestic employment, crowd-out, the gender wage gap, unemployment insurance, disability benefits, universal preschool, childcare and employment, immigration and wages, and more.

Knepper and Wheaton use this narrower dataset to train a machine learning model to categorise the rest of the papers in the dataset, as to how left-wing (or right-wing) the conclusions are. For instance, a paper that concludes that the minimum wage reduces employment is more right-wing, whereas one that concludes that there is no disemployment effect of the minimum wage is more left-wing. Knepper and Wheaton define an author as left-wing if they published more left-wing papers than right-wing ones over the previous five years, and the reverse for right-wing authors. They then use the larger dataset to investigate what happens to each economist who undergoes an 'ideological reversal'. They first outline some descriptive facts based on their dataset, including:

• Fact #1: The typical author mostly publishes results on one side of the political spectrum.

• Fact #2: Ideological reversals are not rare; they occur at least once for 40% of authors.

• Fact #3: Ideological reversals become much more common later in an author’s career, with authors essentially never undergoing a reversal in the first decade of their career.

• Fact #4: Most ideological reversals do not represent a permanent defection to the other side of the political spectrum, but rather the beginning of repeatedly publishing results on both sides of the spectrum.

• Fact #5: Ideological reversals occur much more frequently amongst authors who are (initially) classified as right-wing.

That does seem like a surprisingly high proportion of economists who undergo at least one ideological reversal. However, perhaps we should take comfort in that - if the results point in a particular direction, our conclusions should say that, even if that conclusion is inconsistent with our previous conclusions on the same topic.

Do these ideological reversals matter though? Knepper and Wheaton employ a difference-in-differences analysis, comparing the difference in citations (and other metrics) between authors who did, and did not, undergo an ideological reversal, between the time before, and after, the reversal occurred. In other words, they look at whether citation counts rise more for economists who have an ideological reversal than for otherwise similar economists who do not. The results are striking, with:

...a sharp clear increase in citation count following an ideological reversal with essentially no evidence of pre-trends... The citation boost accumulates to approximately 9 over a one-decade period and 30 over a two-decade period.

The results remain consistent when Knepper and Wheaton limit the analysis to papers published before the ideological reversal, and when they limit the analysis to papers in the meta-analysis only (showing that the machine learning approach doesn't drive the results). Knepper and Wheaton also find evidence consistent with no change in the quality of papers before and after the ideological reversal, and that:

Both left-to-right and right-to-left reversals are rewarded by increased citations of roughly the same magnitude. The boost in citations received subsequent to a left-to-right reversal is mostly driven by citations from right-wing authors, and the boost in citations received subsequent to a right-to-left reversal is mostly driven by citations from left-wing authors. Encouragingly, however, the new right-wing (left-wing) audience garnered by a left-to-right (right-to-left) reversal... also engages with and cites the author's previous left-wing (right-wing) papers. This dynamic suggests that ideological reversals help prevent the formation of echo chambers in economics academia and expose authors to opposite ideological findings.

This last result is particularly important, and I believe it allows us to conclude that economists need not fear ideological reversals. In doing so, they can attract a new audience from the other side of the ideological spectrum, bringing the two sides closer together. Hopefully through that, we end up with higher-quality research overall.

[HT: Marginal Revolution, last year]