In this issue:

“China shock” fragility: According to David Autor, David Dorn, and Gordon Hanson (2013), the “China shock” hit the United States from 1990 to 2007. When corrections by Kirill Borusyak et al. (2022) are fully applied, Joseph Francis argues, the harm of Chinese imports to unemployment, labor force participation, wages, and household incomes disappear. “China shock,” Francis argues, illustrates how the “credibility revolution” very much leaves the con in econometrics. (The commented-on authors are hereby invited to reply in a future issue.)

The predictions did not come true: A June 2023 decision, SFFA v. Harvard, held that race-based admissions are unconstitutional. Thirty-three selective colleges forecast Black enrollment declines of 50 to 70 percent. Fifteen research universities assured the Court that race-neutral admissions “would undercut” the diversity they seek. David Card estimated that eliminating racial preferences would cut the Black share of Harvard’s admitted class from 14 percent to 6 percent. Three years on, David Kane reports that the predictions did not come anywhere close to true.

Science confections: Following up on his critique of Jonathan Pekar et al. in Science, Michael Weissman now criticizes Michael Worobey et al. in Science, who claim that case locations and nucleic acid samples showed that SARS-CoV-2 had first been introduced to humans at the Huanan Seafood Market. Several lines of evidence suggest the introduction to humans was earlier and elsewhere. (The commented-on authors are hereby invited to reply in a future issue.)

The fall of Fama-French and momentum factors: Commenting on Clifford Asness, Eugene Fama, and Kenneth French, Michael O’Connor argues that momentum’s circa-2003 demise and that of market capitalization and the book-to-market ratio about a decade later represent a structural break or ‘regime change.’ (The commented-on authors are hereby invited to reply in a future issue.)

All in the family: Kenneth Judd and Karl Schmedders take issue with an article in Journal of Economic Literature by Jesús Fernández-Villaverde. They say that he overstates the newness of neural-network or “deep learning” solvers and that such solvers should be understood as inside the family of projection and weighted-residual solvers. (The commented-on author is hereby invited to reply in a future issue.)

Is chatbot validation valid? Alexis Akira Toda reports on Gemini, Refine, Claude, and ChatGPT on errors in four published papers in mathematical economics. The chatbots generated false positives—endorsing flawed proofs—and varied in how much guidance they needed to find the error. ChatGPT Pro performed best, Claude was middling, and Gemini worst. Corrections of the original errors had already been published at the time of the experiment, and so a chatbot’s success might reflect its canvassing for published commentary. Since the chatbots generated false positives, however, we know that they are fallible one way or another.

How are so-called digital public goods provided? The United Nations and its Digital Public Goods Alliance have constructed an ambitious framework for certifying, funding, and deploying open-source software in developing countries. The soundness of the UN’s approach is, according to Vidar Andre Utvik and coauthors, illustrated by the rapid development of Covid-19 surveillance tools in Sri Lanka and Norway. Here, John Levendis argues that their own evidence reveals that local professionals cooperated voluntarily and that community innovation preceded WHO guidance, not the reverse. (The commented-on authors are hereby invited to reply in a future issue.)

On Haavelmo’s adoption of Neyman-Pearson theory: Trygve Haavelmo’s (1944) monograph “The Probability Approach in Econometrics” is based on a strict adoption of Neyman-Pearson testing theory. Here, Tom Engsted argues that Haavelmo resorted to the notion of a hypothetical infinite population and a distinctly non-frequentist (Bayesian-like) interpretation of probability with the aim of inductive inference, in direct contradiction with Neyman-Pearson theory.

1939–1945: Housing policy in Denmark: In a critique of the primary literature on the subject, Jens Hansen explains the origins of Danish rent control and other housing regulation. The interventions have wrought great hardship and no discernible benefits. The history exemplifies the intervention dynamic.

Where credit is due: Alexis Akira Toda reports on some curious failures to cite predecessors and brings credit to the slighted authors and papers. (The commented-on authors are hereby invited to reply in a future issue.)

Greening on the edge: An article models sustainable product development under crowdfunding and regulation. Here, Marco Sorge argues that the authors disregard corner solutions for environmental quality, which robustly arise across admissible parameter configurations, and conduct comparative statics where no interior solution exists. A complete characterization of the equilibrium corrects, and in some cases contradicts, their conclusions. (The commented-on authors are hereby invited to reply in a future issue.)

Book-manuscript symposium:
Gregory Clark on genetics and social mobility

The third book in Clark’s trilogy is titled To Have and Have Not: The Determinants of Social Status in England, 1600-2026:

EJW Audio:

Notice: Heckscher’s Mercantilism lives! — vol. 1, vol. 2.