Das legt eine Analyse von Timothy Taylor (Editor beim JEP) nahe.
Taylors Analyse der Gründe dafür:
"Ultimately, longer papers in academic research journals reflect an evolving consensus about what constitutes a necessary and useful presentation of research results. [...]
An economics research paper back in the 1960s often made a point, and then stopped. An academic research paper in the second decade of the 21st century is more likely to spend a few pages setting the stage for their argument, setting the stage for the big question, give some sense in the introduction of the paper of main results, have a section discussing previous research, have a section giving a background theory, and so on.
Changes in information and computing technology have pushed economics papers to become longer. [...] There has been a movement in the last couple of decades toward "experimental economics," in which economists vary certain parameters--either in a laboratory with a bunch of students, or often in a real-world setting--which also means reporting in the research paper what was done and what data was collected. [...]
In the past, the ultimate constraint on length of academic journals was the cost of printing and postage. But in web-world, where we live today, distribution of academic research can have a near-zero cost. Editors of journals that are primarily distributed on-line have less incentive to require short articles.
Finally, one should mention the theoretical possibility that academic writing has become bloated over time, filled with loose sloppiness, with unneeded and length excursions into technical jargon, and occasion bouts of unrestrained pompousness.
Whatever the underlying cause of the added length of articles in economics journals, it creates a conflict between the underlying purposes of research publications. One purpose of such publications is to create a record of what was done, so that the data, theory, and arguments are spelled out in detail. However, another purpose is to allow findings to be disseminated among other researchers, as well as students and policy-makers, so that the results can be more broadly considered and understood."