AI analysis requested by The Unjournal

Structural sensitivity: would other reasonable model choices change the results?

The paper builds its model from a series of choices, each defensible and each drawn from a literature: a task-based production structure, a capital-supply schedule, search and matching, a wage rule. Would an equally reasonable set of choices have led to very different results? This page lists the main choice points with alternatives, for evaluators to amend, and reports one pilot change.

In brief

Pilot: how fast capital reaches the paper’s schedule

The change. In the paper, the capital stock is always on its supply schedule. In the pilot, each month the stock closes a fixed fraction of its gap to the schedule; the half-life is the time to close half the gap. A half-life of zero is the paper. The paper itself says compute is “built in a year or two” (p. 26), so half-lives of 6–12 months are close to its own description; 24 and 48 months stand for slower physical limits.

Two long-run elasticities. The paper sets ε = 3, half the value of about 6 implied by Moll, Rachel and Restrepo (p. 9, footnote), with the short horizon in mind. Adding a lag to ε = 3 may count that delay twice; the cleaner comparison is ε = 6 reached with a lag. Both are shown. Everything else stays at the paper’s values.

Checks. With the half-life at zero, every monthly series of the 14 printed runs (Tables 3, 5 and 6) equals the unmodified Econ-ARK code bit for bit, and Econ-ARK’s validator finds all 226 published numbers it checks. With an infinite half-life, the stock stays on its no-AI path, and the results equal the paper’s rule at ε = 0 to within 10⁻¹⁵. At zero half-life, the ε = 6 column reproduces the paper’s Table 5.

Extreme scenario, January 2030

GDP, % above no-AI path
202530354006122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): 32.4ε 3 (paper), 6 months: 30.8ε 3 (paper), 12 months: 28.7ε 3 (paper), 24 months: 25.3ε 3 (paper), 48 months: 20.6ε 6 (long-run, Moll et al.), Instant (paper): 37.2ε 6 (long-run, Moll et al.), 6 months: 36.4ε 6 (long-run, Moll et al.), 12 months: 35.1ε 6 (long-run, Moll et al.), 24 months: 32.9ε 6 (long-run, Moll et al.), 48 months: 29.4ε 3ε 6
Cognitive wage, % vs no-AI path
−40−30−20−10006122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): −11.5ε 3 (paper), 6 months: −19.2ε 3 (paper), 12 months: −22.8ε 3 (paper), 24 months: −27.4ε 3 (paper), 48 months: −33.2ε 6 (long-run, Moll et al.), Instant (paper): −3.3ε 6 (long-run, Moll et al.), 6 months: −9.9ε 6 (long-run, Moll et al.), 12 months: −13.0ε 6 (long-run, Moll et al.), 24 months: −17.0ε 6 (long-run, Moll et al.), 48 months: −21.9ε 3ε 6
Cognitive unemployment, %
14151617181906122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): 17.9ε 3 (paper), 6 months: 15.8ε 3 (paper), 12 months: 15.4ε 3 (paper), 24 months: 15.1ε 3 (paper), 48 months: 14.8ε 6 (long-run, Moll et al.), Instant (paper): 18.6ε 6 (long-run, Moll et al.), 6 months: 16.7ε 6 (long-run, Moll et al.), 12 months: 16.1ε 6 (long-run, Moll et al.), 24 months: 15.7ε 6 (long-run, Moll et al.), 48 months: 15.4ε 3ε 6
Average wage, % vs no-AI path
−20−100102006122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): 9.7ε 3 (paper), 6 months: 4.8ε 3 (paper), 12 months: 1.2ε 3 (paper), 24 months: −4.3ε 3 (paper), 48 months: −11.5ε 6 (long-run, Moll et al.), Instant (paper): 18.3ε 6 (long-run, Moll et al.), 6 months: 14.9ε 6 (long-run, Moll et al.), 12 months: 12.2ε 6 (long-run, Moll et al.), 24 months: 8.1ε 6 (long-run, Moll et al.), 48 months: 2.3ε 3ε 6
Labor share, %
404244464806122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): 45.2ε 3 (paper), 6 months: 44.3ε 3 (paper), 12 months: 43.6ε 3 (paper), 24 months: 42.4ε 3 (paper), 48 months: 40.8ε 6 (long-run, Moll et al.), Instant (paper): 46.9ε 6 (long-run, Moll et al.), 6 months: 46.3ε 6 (long-run, Moll et al.), 12 months: 45.8ε 6 (long-run, Moll et al.), 24 months: 45.0ε 6 (long-run, Moll et al.), 48 months: 43.8ε 3ε 6
GDP gain ÷ cognitive wage-bill loss
123406122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): 2.79ε 3 (paper), 6 months: 2.36ε 3 (paper), 12 months: 2.06ε 3 (paper), 24 months: 1.66ε 3 (paper), 48 months: 1.22ε 6 (long-run, Moll et al.), Instant (paper): 3.92ε 6 (long-run, Moll et al.), 6 months: 3.44ε 6 (long-run, Moll et al.), 12 months: 3.11ε 6 (long-run, Moll et al.), 24 months: 2.67ε 6 (long-run, Moll et al.), 48 months: 2.15ε 3ε 6

Each point is one model run; hover over a point for its value. Half-lives are evenly spaced on the axis, not to scale, and each panel has its own vertical scale. The first blue point is the paper’s Table 3; the first orange point is its Table 5 at ε = 6.

Table view: extreme scenario
January 2030ε 3 (paper)ε 6 (long-run, Moll et al.)
Instant (paper)6 months12 months24 months48 monthsInstant (paper)6 months12 months24 months48 months
GDP, % above no-AI path32.430.828.725.320.637.236.435.132.929.4
GDP growth, % a year15.414.814.213.111.417.517.116.716.015.1
Labor share, %45.244.343.642.440.846.946.345.845.043.8
Cognitive unemployment, %17.915.815.415.114.818.616.716.115.715.4
Unemployment, all workers, %11.910.710.510.310.212.211.210.910.710.5
Cognitive wage, % vs no-AI−11.5−19.2−22.8−27.4−33.2−3.3−9.9−13.0−17.0−21.9
Other wages, % vs no-AI33.633.329.723.414.742.443.741.937.831.3
Average wage, % vs no-AI9.74.81.2−4.3−11.518.314.912.28.12.3
Net return to capital, %8.38.89.29.710.67.57.88.08.49.0
Capital stock, % above no-AI path56.351.947.540.731.867.164.461.356.249.0
GDP gain ÷ cognitive wage-bill loss2.792.362.061.661.223.923.443.112.672.15
Substantial scenario: charts and table
GDP, % above no-AI path
67891006122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): 8.3ε 3 (paper), 6 months: 8.0ε 3 (paper), 12 months: 7.6ε 3 (paper), 24 months: 7.0ε 3 (paper), 48 months: 6.0ε 6 (long-run, Moll et al.), Instant (paper): 9.1ε 6 (long-run, Moll et al.), 6 months: 8.9ε 6 (long-run, Moll et al.), 12 months: 8.7ε 6 (long-run, Moll et al.), 24 months: 8.3ε 6 (long-run, Moll et al.), 48 months: 7.5ε 3ε 6
Cognitive wage, % vs no-AI path
−6−4−20206122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): −0.3ε 3 (paper), 6 months: −1.6ε 3 (paper), 12 months: −2.4ε 3 (paper), 24 months: −3.7ε 3 (paper), 48 months: −5.4ε 6 (long-run, Moll et al.), Instant (paper): 1.3ε 6 (long-run, Moll et al.), 6 months: 0.3ε 6 (long-run, Moll et al.), 12 months: −0.3ε 6 (long-run, Moll et al.), 24 months: −1.3ε 6 (long-run, Moll et al.), 48 months: −2.7ε 3ε 6
Cognitive unemployment, %
4.14.24.34.44.54.64.706122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): 4.5ε 3 (paper), 6 months: 4.3ε 3 (paper), 12 months: 4.2ε 3 (paper), 24 months: 4.2ε 3 (paper), 48 months: 4.2ε 6 (long-run, Moll et al.), Instant (paper): 4.6ε 6 (long-run, Moll et al.), 6 months: 4.4ε 6 (long-run, Moll et al.), 12 months: 4.3ε 6 (long-run, Moll et al.), 24 months: 4.2ε 6 (long-run, Moll et al.), 48 months: 4.2ε 3ε 6
Average wage, % vs no-AI path
−4−202406122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): 2.1ε 3 (paper), 6 months: 1.3ε 3 (paper), 12 months: 0.6ε 3 (paper), 24 months: −0.7ε 3 (paper), 48 months: −2.4ε 6 (long-run, Moll et al.), Instant (paper): 3.7ε 6 (long-run, Moll et al.), 6 months: 3.1ε 6 (long-run, Moll et al.), 12 months: 2.6ε 6 (long-run, Moll et al.), 24 months: 1.7ε 6 (long-run, Moll et al.), 48 months: 0.3ε 3ε 6
Labor share, %
54.55555.55656.55706122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): 56.1ε 3 (paper), 6 months: 55.9ε 3 (paper), 12 months: 55.7ε 3 (paper), 24 months: 55.3ε 3 (paper), 48 months: 54.8ε 6 (long-run, Moll et al.), Instant (paper): 56.5ε 6 (long-run, Moll et al.), 6 months: 56.4ε 6 (long-run, Moll et al.), 12 months: 56.2ε 6 (long-run, Moll et al.), 24 months: 56.0ε 6 (long-run, Moll et al.), 48 months: 55.6ε 3ε 6
GDP gain ÷ cognitive wage-bill loss
0246806122448capital half-life, months (0 = paper)ε 3 (paper), Instant (paper): 4.78ε 3 (paper), 6 months: 3.93ε 3 (paper), 12 months: 3.31ε 3 (paper), 24 months: 2.55ε 3 (paper), 48 months: 1.81ε 6 (long-run, Moll et al.), Instant (paper): 7.55ε 6 (long-run, Moll et al.), 6 months: 6.38ε 6 (long-run, Moll et al.), 12 months: 5.50ε 6 (long-run, Moll et al.), 24 months: 4.35ε 6 (long-run, Moll et al.), 48 months: 3.15ε 3ε 6
January 2030ε 3 (paper)ε 6 (long-run, Moll et al.)
Instant (paper)6 months12 months24 months48 monthsInstant (paper)6 months12 months24 months48 months
GDP, % above no-AI path8.38.07.67.06.09.18.98.78.37.5
GDP growth, % a year5.45.35.24.94.65.75.65.65.45.2
Labor share, %56.155.955.755.354.856.556.456.256.055.6
Cognitive unemployment, %4.54.34.24.24.24.64.44.34.24.2
Unemployment, all workers, %4.64.44.44.34.34.64.44.44.44.3
Cognitive wage, % vs no-AI−0.3−1.6−2.4−3.7−5.41.30.3−0.3−1.3−2.7
Other wages, % vs no-AI5.95.75.13.92.17.37.47.06.34.9
Average wage, % vs no-AI2.11.30.6−0.7−2.43.73.12.61.70.3
Net return to capital, %7.07.17.27.47.76.86.96.97.17.3
Capital stock, % above no-AI path13.813.012.010.58.415.715.214.613.511.8
GDP gain ÷ cognitive wage-bill loss4.783.933.312.551.817.556.385.504.353.15
Modest scenario: table
January 2030ε 3 (paper)ε 6 (long-run, Moll et al.)
Instant (paper)6 months12 months24 months48 monthsInstant (paper)6 months12 months24 months48 months
GDP, % above no-AI path1.61.61.51.51.41.71.71.71.61.6
GDP growth, % a year2.42.42.42.42.32.42.42.42.42.4
Labor share, %59.459.459.459.359.359.559.559.559.459.4
Cognitive unemployment, %2.92.92.92.92.93.02.92.92.92.9
Unemployment, all workers, %3.93.93.93.93.93.93.93.93.93.9
Cognitive wage, % vs no-AI0.40.30.20.1−0.20.70.60.50.40.2
Other wages, % vs no-AI1.11.11.11.00.71.41.41.41.31.1
Average wage, % vs no-AI0.70.60.50.40.20.90.90.80.70.6
Net return to capital, %6.66.66.66.66.76.56.66.66.66.6
Capital stock, % above no-AI path2.32.22.12.01.72.62.62.52.42.2
GDP gain ÷ cognitive wage-bill loss14.5011.179.096.714.5273.5639.3127.0216.859.84

The gain-to-loss ratio is not meaningful here: the cognitive wage-bill loss is close to zero.

What the pilot shows

Limits of the pilot
  • One change among the eleven choice points, at otherwise fixed paper values; not the joint grid a full version needs.
  • Partial adjustment is a simple stand-in for build lags. The half-lives are illustrative, not estimated; the only anchor used is the paper’s “a year or two”.
  • The lag applies to all capital, not only compute, and starts with the stock on its no-AI path in January 2024. Within a month, every capital market uses the same short-run schedule, built from last month’s stock.
  • The code was written by Claude and has not been reviewed by a person. Claude is made by Anthropic, which publishes the paper.

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Code, results and how to reproduce

The pilot changes two functions in Econ-ARK’s independent rebuild of the model (econ-ark/econ-scenarios, commit 87170fa, MIT licence; Zenodo DOI 10.5281/zenodo.22839070). reproduce.sh copies their package, applies the patch, runs the three checks above and the grid, and writes the logs listed here. Files end in .txt so that they open in a browser; drop the suffix before running. Credit for the model rebuild belongs to Econ-ARK; errors in the change are ours.

Prepared 29 October 2026. The working record, with every run, is kept in The Unjournal’s review folder for this paper.

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