Do economists act like the self-interested decision-makers from our models, and if so, why?

Economics models typically assume that decision-makers are self-interested, trying to maximise their own 'economic rent'. Does exposure to these models, and the assumption of self-interest, lead people who have studied economics to make more self-interested decisions? Or, are people who make more self-interested decisions more likely to study economics (perhaps because it accords with their already-established world view)?

These are questions that many studies have tried to grapple with (and which I have written about before, most recently in this 2023 post). What is needed is a good systematic review of the literature. We don't have that, but this 2019 article by Simon Hellmich (Bielefeld University), published in the journal The American Economist (sorry, I don't see an ungated version online), provides a review of the literature (up to 2019, of course).

Hellmich prefers the term "people trained in economics" rather than "economists", noting that much of the literature focuses on undergraduate students who have only taken one or a few courses in economics, and can hardly be considered "economists". Hellmich reviews the empirical literature that comes from both lab experiments and field experiments, although it is worth noting that most of the literature makes us of lab experiments. He draws three broad conclusions from the literature:

• People trained in economics behave more in accordance with the standard paradigms of their discipline in situations that are typically described in economic categories. They tend to prioritize their self-interest in games... but this is at least in part an outcome of their expectations about other peoples’ behavior and social interaction can strengthen their cooperativeness.

• Most of the experiments reviewed here involve economic decisions (i.e., involve the allocation of money); in most of the less obviously economic decisions, people trained in economics do not seem to be much less concerned with other people’s welfare and no more likely than other people to expect opportunism from other individuals. All in all... there is not much unambiguous support for the view that training in economics affects the fundamental preferences of people by making them more “selfish” or opportunistic.

• Most empirical evidence seems to be consistent with the self-selection assumption and more than half of the relevant studies—some of them providing high-quality evidence— seem to suggest that there are training effects... Probably both forces play a role.

In other words, the review doesn't really tell us much more than we already knew. People trained in economics behave in a more self-interested way, and part (or perhaps most) of the reason for that is the types of people who choose to train in economics. What Hellmich adds to this research question, though, is a concern about the way that previous research has tried to identify the effects, and in particular, the way that the research is framed (from the perspective of the research participants). He notes that:

...most of the experiments reviewed here lack sufficient consideration of the fact that human subjects in experiments do not mechanistically and passively respond to selected stimuli consciously created and controlled by the experimenter, and in so doing reflect their fundamental preferences. Instead, human subjects tend to interpret cues given to them—perhaps unconsciously— by the experimenter or the environment and what they might know about the theories underlying the experiment... In social dilemmas that involve decisions that are clearly identifiable as being of an economic nature (e.g., because they involve the allocation of money), people compete more than if this trait is less clear... In market-like contexts, there is broad acceptance of self-interest. It may even constitute the social norm to follow...

In other words, perhaps people trained in economics act differently in these experiments because the lab environment, and the wording of the decisions, induces them to apply their economics skills. This would explain why, in the field experiments conducted in more naturalistic settings, the behaviour of people trained in economics differs much less from other people than it does in the lab experiments. Hellmich is essentially arguing for more investigation of real-world decisions, and how they differ between people trained in economics and people who are not. That seems like a sensible suggestion.

However, the overwhelming result from Hellmich's review is that people trained in economics are "different" in meaningful ways (including higher levels of self-interest), and that difference should be recognised. He concludes that:

...as provisional steps, we should perhaps try to make students more aware of the fact that most economists understand key elements of neoclassical theory—like the homo economicus—as an instrument to explain macrophenomena rather than as a normative model of micro-behavior and how other elements of the “culture” of the discipline might make their judgments deviate from that of other groups.

In other words, our students (and other people) need to understand that self-interested behaviour is an assumption that we make in economic models, and not an ideal to strive for.

Read more:

• Does education in economics make politicians corrupt?
• The impact of business and economics education on moral competence
• This study tells us nothing about whether studying economics make students less ethical
• Does studying economics make you selfish?

Does studying economics make you selfish?

It's a common trope that studying economics makes people more selfish (see for example this New York Times article (paywalled), or this NPR article). However, is it true? As I've noted before, studying economics appears to have no effect on moral reasoning. However, most papers on similar topics do a pretty poor job of actually teasing out the effect of studying economics (see here or here, for example). Often, this is because the studies don't do a good job of controlling for who selects into studying economics in the first place. So, any effects might be attributable to differences in students before they study any economics.

So, I was interested to read this new article by Daniele Girardi (King's College London), Sai Madhurika Mamunuru (Whitman College), Simon Halliday (University of Bristol), and Samuel Bowles (Santa Fe Institute), published in the Southern Economic Journal (open access). Girardi et al. look at the effect of studying intermediate microeconomics on measures of self-interest (derived experimentally using a dictator game), reciprocity (derived experimentally using a trust game), perceptions of self-interest and reciprocity (measured by survey responses to how other participants would respond in the dictator and trust games), and some measures of policy preferences.

The research participants were students at the University of Massachusetts Amherst:

Students from four different intermediate microeconomics courses and from one course outside of the social sciences comprise our sample. A course in “Nutrition and Metabolism” serves as a control non-economics course. The economics courses vary: two courses (which we call Conventional I and Conventional II) are fairly standard intermediate microeconomics courses using Pindyck and Rubinfeld (2012) and Perloff (2011); a third (Post Walrasian) course uses Bowles and Halliday (2022) and focuses on strategic interactions and contractual incompleteness alongside standard topics of optimization (crucially it contains behavioral experiments and models of social preferences); finally, the fourth course (Conventional plus social preferences), is an online course using Frank (2008). The four intermediate microeconomics courses all had the same enrollment prerequisites and identical description in the online enrollment system.

Students were surveyed at the beginning and the end of their course, which allowed Girardi et al. to employ a difference-in-differences approach. Essentially, this involves looking at the difference between students enrolled in the economics courses and students enrolled in nutrition course, before and after their course. If the change in behaviour or preferences for economics students was different than the change in behaviour for nutrition students, this could plausibly be attributed to the effect of studying economics.

Girardi et al. find that:

...a one-semester intermediate microeconomics course has little to no effect on experimental measures of social preferences or on expectations about other people's social preferences. Our estimates of the effect on measures of altruism and reciprocity are close to zero and do not differ across the differing content of the courses. We also find little evidence of an effect on the students' policy preferences or political orientations. The one exception concerns immigration: studying intermediate microeconomics (whatever the course content) seems to make students less opposed to highly restrictive immigration policies.

Even the last result about opposition to immigration policies only appears in one analysis, is based on responses to a single question, and is not robust to alternative specifications of the policy preference variables. So, studying economics appears to have no effect on selfishness or policy preferences. However, Girardi et al. note that:

The results could depend on the fact that the main effect of studying economics occurs at the introductory level, or that a single semester is too brief an exposure to produce a detectable effect.

That's possible (although Girardi et al. are quick to point out that that interpretation would be at odds with one other study that found a larger effect at intermediate than at introductory level). However, I would suggest that there is another good reason to doubt these results. The Economics Department at the University of Massachusetts Amherst is well known within the discipline as being a heterodox department. It is not mainstream, and it seems to me that it is unlikely that it attracts a majority of mainstream economics students. The types of students who self-select into studying economics at Amherst may well be students who would not be swayed into selfishness by discussions of rational utility maximisation. Alternatively, even courses that are 'mainstream' by name may approach the subject very differently at Amherst than would occur at a more traditional economics department. This study tries to address this issue by including 'conventional' intermediate economics courses, that are taught using commonly used textbooks. However, the way that lecturers approach the teaching of the subject matters too, and that is very likely to be different at Amherst than at other universities.

So, unfortunately this study may tell us little about how the teaching of economics at a traditional economics department affects student selfishness. We likely need a broader study, that uses a similar approach, but either has a sample at a more traditional economics department or, even better, looks across several economics departments at different universities.

Read more:

• Does education in economics make politicians corrupt?
• The impact of business and economics education on moral competence
• This study tells us nothing about whether studying economics make students less ethical

Grading bias, classroom behaviour, and assessing student knowledge

There is a large literature that documents teachers' biases in the grading of student assessments. For example, studies have used comparisons of subjectively graded (by teachers) assessments and objectively graded (or blind graded) assessments, to demonstrate gender bias and racial bias. However, grading bias may not just arise from demographics. Teachers may also show favouritism towards well-behaved students (relative to badly-behaved students). The challenge with demonstrating that bias is that researchers often lack detailed measures of student behaviour.

That is not the case for the research reported in this recent article by Bruno Ferman (Sao Paulo School of Economics) and Luiz Felipe Fontes (Insper Institute of Education and Research), published in the Journal of Public Economics (sorry, I don't see an ungated version online). They used data from a Brazilian private education company that manages schools across the country, and covered:

...about 23,000 students from grades 6-11 in 738 classrooms and 80 schools.

Importantly, the data includes student assessment results that were graded by their teacher, standardised test results that were machine-graded, and measures of student behaviour, which the company collected in order to "better predict their dropout and retention rates". Ferman and Fontes collate the behavioural data, and:

...classify a student i being assessed in subject s and cycle t as well-behaved (GBits = 1) if she is in the top quartile within class in terms of good behavior notifications received until t by all teachers except the subject s one. We classify bad-behaved students (BBits = 1) analogously.

They then compare maths test scores between well-behaved and badly-behaved students, and show that:

...the math test scores of ill-behaved students (BB = 1) are on average 0.31 SD below those such that BB = 0. The unconditional grade gap between students with GB = 1 and GB = 0 is even greater: 0.54 SD in favor of the better-behaved pupils.

So far, so unsurprising. Perhaps better-behaved students also study harder. However, when Ferman and Fontes control for blindly graded math scores, they find that:

...the behavior effects are significantly reduced, indicating that a share of the competence differences seen by teachers is captured by performance in the blindly-scored tests... Nevertheless, the behavior effects remain significant and are high in magnitude, indicating that teachers confound scholastic and behavioral skills when grading proficiency exams. Our results suggest that the better(worse)-behaved students have their scores inflated (deducted) by 0.14 SD...

This is quite a sizeable effect, amounting to "approximately 60% of the black-white achievement gap". And that is simply arising from teacher grading bias. Ferman and Fontes then go on to show that their results are robust to some alternative specifications, and that there is also apparent teacher bias in decisions of which students are allowed to move up to the next grade.

However, should we care about grading bias? Ferman and Fontes point out that their results:

...characterize an evaluation scheme that is condemned by educators and classroom assessment specialists, which explicitly warn against the adjustment of test scores to reflect students’ behavior... and consider this practice as unethical... Their argument is that achievement grades are the main source of feedback teachers send about the students’ proficiency levels. Therefore, test scores help pupils form perceptions about their own aptitudes and assist them in the process of self-regulation of learning; additionally, they help parents to understand how to allocate effort to improve their children’s academic achievement...

Still, one could argue that biasing test scores may be socially desirable if it induces a student to behave better, generating private benefits to the pupil and positive externalities to peers...

Let me suggest another counterpoint. If grades are a signal to universities or to employers about the relative ranking of students in terms of performance, then maybe you want those grades to reflect students' behaviour as well as students' attainment of learning outcomes. You might disagree, but I'd argue that there are already elements of this in the way that we grade students (in high schools and universities) already. If teachers (and educational institutions) were purists about grades reflecting student learning alone, then we would never estimate student grades for students who miss a piece of assessment, we would never scale grades (up or down). The fact that we do those things (and did so especially during the pandemic) suggests that student grades already can't be interpreted solely as reflecting students' attainment of learning outcomes.

Employers (and universities) want grades that will be predictive of how a student will perform in the future. However, academic achievement is an imperfect measure of future performance of students. This is demonstrated clearly in this recent article by Georg Graetz and Arizo Karimi (both Uppsala University), published in the journal Economics of Education Review (open access). They used administrative data from Sweden, focusing mainly on the cohort of students born in 1992. Graetz and Karimi are most interested in explaining a gender gap that exists between high school grades (where female students do better) and the standardised Swedish SAT tests (where male students do better). Specifically:

...female students, on average, outperform male students on both compulsory school and high school GPAs by about a third of a standard deviation. At the same time, the reverse is true for the Swedish SAT, where female test takers underperform relative to male test takers by a third of a standard deviation...

Graetz and Karimi find that differences in cognitive skills, motivation, and effort explain more than half of the difference in GPAs between female and male students, and that female students have higher motivation and exert greater effort. In contrast, there is selection bias in the SAT scores. This arises in part because Swedish students can qualify for university based on grades, or based on SAT scores. So, students that already have high grades are less likely to sit the SATs. Since more of those students are females with high cognitive skills, the remaining students who sit the SAT test disproportionately include high-cognitive-skill males, which is why males on average perform better in the Swedish SATs.

However, aside from being kind of interesting, that is not the important aspect of the Graetz and Karimi paper that I want to highlight. They then go on to look at the post-high-school outcomes for students born in 1982, and look at how those outcomes relate to grades and SAT scores. In this analysis, they find that:

Grades and SAT scores are strong predictors of college graduation, but grades appear about twice as important as SAT scores, with standardized coefficients around 0.25 compared to just over 0.1...

A one-standard-deviation increase in CSGPA and HSGPA is associated with an increase in annual earnings of SEK15,500 and 25,200, respectively (SEK1,000 is equal to about USD100). But for the SAT score, the increase is only SEK8,000.

In other words, high school grades are a better predictor of both university outcomes (graduation) and employment outcomes (earnings) than standardised tests. This should not be surprising, given that, when compared with standardised tests, grades may better capture student effort and motivation, which will be predictive of student success in university and in employment. And to the extent that good student behaviour is also associated with higher motivation and greater effort, perhaps we want grades to reflect that too. [*]

None of this is to say that we shouldn't be assessing student knowledge. It's more that grades that represent a more holistic measure of student success, will be more useful in predicting future student performance. That is more helpful for employers, and as a result it may be more helpful for encouraging students to study harder as well.

*****

[*] Of course, selection bias matters here too. In the case of the Swedish SATs, the most motivated and hardest working students may have opted out of the SAT test entirely. However, the analysis that Graetz and Karimi undertook is (I think) limited to students who had both grades and SAT scores recorded.

This study tells us nothing about whether studying economics make students less ethical

Does studying economics make students less ethical? The research question is interesting and potentially important (and I've written about similar questions before - see here and here). Answering it, though, is pretty challenging. Simply comparing some measure of ethics between students that have studied economics and students have not studied economics is no good, because perhaps less ethical students choose to study economics. That would create a problem of selection bias. Similarly, comparing some students who chose to do economics early in their degree programme, and students who chose to leave economics for later, faces the same problem.

So, I was quite disappointed when I read this book chapter by Christian Mastilak (Xavier University) and co-authors (ungated earlier version here). Promisingly, they conduct a lab experiment with business school students, some of whom have studied microeconomics already, and others that haven't, and test how ethical their choices are across a few experiment tasks. They find that:

...participants with exposure to agency theory assumptions through either an experimental manipulation invoking a competitive, wealth-maximizing frame consistent with common agency theory or prior microeconomics coursework acted more unethically than participants who had neither exposure to agency theory.

By "agency theory" here, Mastilak et al. are really referring to economic theory more generally (and in fact that's how they refer to it in the ungated version of the paper). They started their experiment by having participants play a prisoners' dilemma game. The game had two different framings, and each participant saw only one framing: (1) as a competition between two competing firms, with an emphasis on each firm's individual payoff; or (2) as a collaboration between two NGOs, with an emphasis on the joint payoff to society as a whole.

They then went on to have their participants engage in other tasks, a few of which were used to evaluate ethical behaviour (or otherwise). They find no differences between participants on two of the tasks, but they do find statistically significant differences on one task, that involves participants overstating a budget request, where they would receive a payout that enriches them.

Mastilak et al. compare the budget request between participants who were exposed to the competitive or cooperative framing of the prisoners' dilemma, and find that participants exposed to the competitive framing made larger budget requests (thereby acting less ethically). However, comparing participants who had completed prior economics with those that had not, there were no statistically significant differences. Now, see if you can follow these bits of the paper:

Panel B reports a two-way ANOVA. The effect of the experimental condition (frame) is significant (p = 0.011).

Initially, it appears there is no effect of prior microeconomics coursework as the effect of prior microeconomics coursework is not significant (p = 0.193)... coursework. Tests of simple main effects are reported in Table 1, Panel C. For participants who had taken microeconomics, the agency frame condition had no effect (p = 0.201). For participants who had not taken microeconomics, the agency frame condition had a significant effect (p = 0.026).

We interpret our tests of simple effects as indicating that either agency frame manipulation or prior economics coursework is sufficient to increase unethical behavior...

Wait - read that last bit again. They interpret their results as indicating that "either agency frame manipulation or prior economics coursework" increases unethical behaviour. And yet, one paragraph earlier, they clearly say that "the effect of prior microeconomics coursework is not significant", and that the effect of framing on participants who had taken microeconomics was also not statistically significant.

And even their results of the agency frame having a significant effect for those who had not taken microeconomics is shaky, because their whole sample size of participants who had not taken microeconomics was 11 students. And because microeconomics is compulsory for business students, those 11 students are students who had left economics until later in their degree programme, so can be assumed to be meaningfully different from the other students (self-selection bias).

Who peer reviewed this book chapter? The headline result is basically not supported by the analysis. The effect of the prisoners' dilemma framing on subsequent unethical choices is interesting (although I have some issues with the particular way they conducted the framing), but it tells us nothing about whether studying economics affects ethical behaviour.

Experimental studies can often help us to better understand relationships in a controlled environment. However, studies like this one do not help at all.

Read more:

• Does education in economics make politicians corrupt?
• The impact of business and economics education on moral competence

Why study economics? It causes higher incomes...

I've posted a number of times about why students should study economics (see the long list at the end of this post). Several of those posts highlight the earnings premium that economics students receive - students who study economics earn more than those studying in many other fields. Most of the evidence I've cited in those posts is observational - it involves a straight comparison between the earnings of economics majors and the earnings of other students. It could rightly be criticised as not demonstrated that economics causes higher earnings. Perhaps the types of students who study economics would earn more, even if they studied sometime else instead of economics - we refer to this as selection bias, because in this case it would mean that better students are selecting to study economics.

A recent working paper by Zachary Bleemer (University of California, Berkeley) and Aashish Mehta (University of California, Santa Barbara) sets out to solve the selection bias problem and provide causal estimates of the impact of studying economics on income. They make use of data from the University of California as Santa Cruz, which implemented a grade point threshold in 2008 that students needed to meet in order to be admitted into an economics major (a GPA of 2.8 based on grades in the first two economics courses). Students who are very close to, but above, the threshold should be very similar to students who are very close to, but below, the threshold. Effectively, whether or not those students very close to the threshold could choose to do the economics major or not is random. So, comparing the incomes of those two groups of students shows how much doing an economics major matters - this is referred to as a regression discontinuity design, because if the threshold has an effect, it will show up as a clear break in a regression line.

Bleemer and Mehta found that:

Among near-threshold students, we find that majoring in economics caused a $22,000 (58 percent) increase in students’ annual early-career wages without otherwise impacting their educational investment (as measured by difficulty-adjusted average grades and weekly hours spent studying) or outcomes (like degree attainment and graduate school enrollment).

In other words, students above the threshold (and able to study economics) earned 58 percent more. Here's part of Figure 1 that shows the break:

 

The blue dotted line is the threshold (the GPA that students needed to achieve in the first two economics courses, in order to be admitted to the major). The black lines track the relationship between GPA and income for those below the threshold, and those above the threshold. Notice that the black line jumps up significantly at the threshold - that demonstrates the $22,000 extra that economics majors earn compared with non-economics majors.

Interestingly, this gap appears for all student groups:

The estimated returns to majoring in economics are near-identical when estimated separately by student gender: $21,700 (s.e. $8,800) for men, $22,600 ($5,700) for women... The return is also similar in magnitude among underrepresented minority (black, Hispanic, and Native American) students: $27,600 ($13,500).

Studying economics is clearly good for all students in this sample. Bleemer and Mehta then go on to show that about half of the wage premium arises because of differences in the industries that economics majors tend to be employed in (finance, insurance, real estate, and accounting) compared with non-economics majors.

Overall, the conclusion is that the monetary returns to studying economics are high, and as I noted above, now we can say with more certainty that it is studying economics that is a cause of those higher earnings.

[HT: Marginal Revolution]

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The impact of business and economics education on moral competence

Last year I wrote a post on whether economics education made politicians more corrupt. It's an interesting question, whether learning about economics alters moral reasoning and makes graduates more corrupt (there are at least some who would quickly buy into this line of argument). Unfortunately, that paper didn't actually answer that question, because it confused correlation with causality. However, a new paper published in the Journal of Business Ethics (ungated version here) by Katrin Hummel, Dieter Pfaff, and Katja Rost (all University of Zurich) gets us a lot closer to understanding whether business and economics education affects moral reasoning.

The authors rightly identify that there are both selection effects (students who choose to study business and economics might be systematically different in terms of moral reasoning from those who study in other fields) and treatment effects (the effect of studying business and economics over and above any difference based on selection). To tease apart the effects, the authors surveyed over 3000 bachelor's and master's students, across six faculties: (1) theology; (2) law; (3) economics and business; (4) medicine; (5) arts; and (6) science. Since most students in Swiss universities progress from bachelor's to master's degrees in the same university (and most stay on to do the master's degree rather than exiting with a bachelor's degree), they essentially observe a cohort of students before, and a cohort of students after, their undergraduate education, as well as students in business and economics, and a range of control disciplines.

They claim to find:

...that both the self-selection as well as the treatment effect of the study of business and economics on students' MJC [Moral Judgment Competence - their measure of moral reasoning] do not exist.

I'd quibble slightly with that summary of their results, because actually there are some statistically significant differences that suggest selection effects - in particular, theology students have significantly higher MJC scores, even after controlling for a range of demographic and other variables, and the size of the effect is about one quarter of a standard deviation. However, regardless of that result there are no treatment effects that suggest that business and economics education reduces moral judgement competence. So, overall nothing to suggest that business and economics education reduces the level of morality in students. Phew!

Some people would (rightly) be worried about the external validity of the results. This study was based on a single university. I'd suggest that this is an invitation for some cross-university comparative research, particularly comparing European universities with British and/or North American universities, to better understand whether the findings are generalisable.

Some of the other results are interesting as well. Quoting (selectively) from the paper:

The results further reveal a significant negative effect of political attitude on MJC, indicating that left-oriented persons have higher C-scores...

Plenty of people would agree with that result, but probably not this one:

Regarding gender, the results suggest that male students have higher MJC.

It seems to contradict plenty of previous research, but apparently the MJC measure is known to be biased towards males. The only treatment effect that was statistically significant was a surprise to me, and somewhat disturbing:

Bachelor's education in medicine in particular seems to significantly reduce students' initially extraordinarily high MJC. This negative impact of medical education on students' MJC is also documented by other researchers... and these researchers explain this finding by the unfavorable learning environment of medical education, which discourages the use of highest-stage moral reasoning.

So medical doctors are less morally competent after their education than before. However, the fact that none of the other fields showed any impact on MJC, let alone a positive impact, leads the authors to conclude:

Today's universities do not offer a learning environment in which optimal moral development can occur. To facilitate moral development, university teachers must encourage students to engage in problem solving rather than offering prepackaged solutions to moral problems.

Ouch!

[HT: Marginal Revolution]

Newsflash! Researchers in top departments publish in top journals

I just finished reading this new article in Applied Economics Letters by Tolga Yuret (Istanbul Technical University), titled "Is it easier to publish in journals that have low impact factors?" (sorry I don't see an ungated version online). The short answer to the titular question is yes, at least according to the data that was used.

However, I struggled to get past the 'so what?' question in this article. I guess maybe I was expecting the unexpected. Yuret's measure of difficulty of publishing was the proportion of the authors publishing in the journal who are affiliated with the top 125 departments. He argues:

A journal is less likely to be accepting papers from the researchers from lower ranked departments if most of the authors are from the top departments. Therefore the measure developed by Moore (1972) also reflects the difficulty in publishing in a journal. Therefore we label his measure as the difficulty measure.

I would argue that if you wanted a measure of difficulty of publishing in a journal, you probably want to start with the acceptance rate (the proportion of submitted papers that are eventually accepted). But then you would want to control for selection bias - authors don't send all papers to the top journals, because we know that not all papers will be accepted there and prefer not to waste our time (or that of the editors and reviewers). So, the more difficult journals to publish in may have low acceptance rates, but those low acceptance rates are actually likely to be biased upwards (they would be even lower if every researcher submitted every relevant paper to them).

When Yuret proceeds to show that there is a high correlation (0.62) between impact factor and his difficulty measure for economics journals, he is simply showing that faculty in top economics departments make up a higher proportion of the authors in the highest impact factor economics journals. Given that faculty in top economics departments are probably higher quality researchers, producing higher quality research, this should not be a surprise. This paper could clearly be filed under 'so what'.

A more interesting question to ask (and probably the question this article was trying to answer but really didn't) is, for a paper of a given quality, is it more difficult to get it accepted in a journal with a high impact factor than a journal with a lower impact factor? I think most researchers' experiences (and certainly mine) would suggest that it is - papers rejected at top journals usually eventually find a home at a lower-ranked journal.

What is perhaps more interesting is that the correlations between impact factor and proportion of authors from top departments are much smaller for the other disciplines that Yuret looked at: chemistry (0.49), physics (0.23), and mathematics (0.22). What's going on in those disciplines (especially physics and mathematics)? Do faculty outside the top departments in those disciplines have a better shot at publishing in the top journals? Given his data I suspect that the lower correlations (for physics and chemistry at least) may be an effect of the other disciplines simply having more journals with top impact factors - it's much harder for faculty at top departments to monopolise the pages of many top journals than it is to do so when there are only a few top journals. Still, the correlations are all positive - researchers in top departments publish in top journals. Surprise!