IESET.
Hypotheses·growth·keynes_1930_growth_targets_actually_met

Pre-1945 Keynes-era claims that growth would ease 'economic problem' within a century (Keynes 1930 'Possibilities for Our Grandchildren') are, by 2030, technically met in OECD per-capita output terms, inviting the degrowth reframing question.

SUPPORTEDengine/runs/keynes_1930_growth_targets_actually_met

SUPPORTED — Population-weighted mean ratio of real GDP per capita (2018/1930) across the 18-country OECD panel is 6.66x, above Keynes's lower bound of 4x. 18/18 countries individually meet the 4x threshold; 4/18 also clear the 8x upper bound.

confidence cueThis is a clear pass for the claim as written. It still applies only to this sample, period, and method.

policy briefNeeds review

In ordinary language

Over a long period, do more market-oriented institutions translate into higher income or productivity, once the comparison looks beyond a single success story?

plain answer

The data clearly moved in the predicted direction. Population-weighted mean ratio of real GDP per capita (2018/1930) across the 18-country OECD panel is 6.66x, above Keynes's lower bound of 4x.

why it matters

Growth claims can look convincing in single success stories. This test asks whether the pattern survives a broader comparison.

how the test works

It compares 18 country or place units from 1930 to 2023, using a descriptive design.

what was measured
What we checked
  • Log income pc cost-of-living adjusted long run
  • Log income pc constant
what this does not prove

A single test is not the whole truth. It narrows the claim under a specific sample, time period, and method. Strong policy conclusions need the pattern to survive nearby tests, alternative data, and serious objections.

verification

No evidence packet has been generated yet.

Results

engine/runs/keynes_1930_growth_targets_actually_met
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Who has skin in the game — schools predicting on this

1 school list this hypothesis as a test of their position. The chips below are school-level scoreboard outcomes, not a second hypothesis verdict.

hypothesis verdict vs scoreboard outcome

The banner verdict judges this hypothesis as written. The scoreboard asks whether each school's polarity-corrected prediction was right. Raw status is not a school win: SUPPORTED supports schools that needed SUPPORTED, but refutes schools that needed REFUTED.

Degrowth / Ecological Macroeconomicswins if SUPPORTEDschool supported

Pre-registration

pre-registered
first-spec commit 4c8ce8e · 2026-07-18T22:11:21Z

Pre-1945 Keynes-era claims that growth would ease 'economic problem' within a century (Keynes 1930 'Possibilities for Our Grandchildren') are, by 2030, technically met in OECD per-capita output terms, inviting the degrowth reframing question.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

PRIMARY (dispositive): the hypothesis is SUPPORTED if the population-weighted mean ratio of real GDP per capita (latest_year / 1930) across the 18-country OECD-style panel, using Maddison MPD2020 (2011 PPP$), is at least 4.0x — Keynes's lower bound. REFUTED if the ratio is below 2.0x (more than half short of the threshold). PARTIAL if the ratio is between 2.0x and 4.0x (direction correct, magnitude short). INFORMATIVE: equal-weighted country mean, median, count of countries individually clearing 4x, and count clearing the 8x upper bound. METHOD_VALID: at least 14 of 18 panel countries observed at both 1930 and the dataset's latest year (Maddison MPD2020 ends 2018; the missing ~12 years of trend would only raise the ratio).

formal test & threshold
test:      keynes_1930_per_capita_ratio_pop_weighted
threshold: PRIMARY: pop_weighted_mean(gdppc[latest] / gdppc[1930]) >= 4.0 across the OECD panel.

Method

Template
descriptive
Clustering
none
Sample
18 countries · 1930 – 2023
Evidence type
descriptive

Long-run descriptive comparison of OECD per-capita output 1930→2030 against Keynes's "Possibilities for Our Grandchildren" 4-8x projection. Reports the log-ratio achieved and tests whether the technical threshold has been met in OECD-output terms.

Data

VariableSourceTransform
log_gdp_pc_ppp_long_run
outcome
maddison:gdppc_ppptier 3
log
log_gdp_pc_constant
outcome
world_bank_wdi:NY.GDP.PCAP.KDtier 2
log
log_population
control
world_bank_wdi:SP.POP.TOTLtier 2
log

● ready  · ● pending  · ● reconstruct-needed

Detailed result card

Keynes 1930 'Possibilities for Our Grandchildren' growth-target check

Verdict: SUPPORTED — Population-weighted mean ratio of real GDP per capita (2018/1930) across the 18-country OECD panel is 6.66x, above Keynes's lower bound of 4x. 18/18 countries individually meet the 4x threshold; 4/18 also clear the 8x upper bound.

Summary

  • Anchor year 1930, latest year 2018 (Maddison MPD2020).
  • Population-weighted mean ratio (latest/1930): 6.66x.
  • Equal-weighted country mean: 7.34x; median 6.40x.
  • 18 of 18 countries individually clear Keynes's 4x lower bound; 4 also clear his 8x upper bound.

Threshold applied

  • PRIMARY (dispositive): population-weighted mean of (GDP-pc[latest] / GDP-pc[1930]) across the 18-country panel >= 4x (Keynes's lower bound).
  • INFORMATIVE: equal-weighted mean, median, share of countries >= 4x, count of countries >= 8x (upper bound).
  • METHOD_VALID: at least 14 of 18 panel countries observed at both endpoints — pass (18/18).

Per-country ratios (Maddison 2011 PPP $)

| Country | GDP-pc 1930 | GDP-pc 2018 | ratio | >=4x? | |---|---:|---:|---:|:---:| | NOR | 5,781 | 84,580 | 14.63x | yes | | IRL | 4,618 | 64,684 | 14.01x | yes | | JPN | 3,334 | 38,674 | 11.60x | yes | | FIN | 4,250 | 38,897 | 9.15x | yes | | AUT | 5,716 | 42,988 | 7.52x | yes | | ITA | 4,631 | 34,364 | 7.42x | yes | | DEU | 6,333 | 46,178 | 7.29x | yes | | SWE | 6,755 | 45,542 | 6.74x | yes | | AUS | 7,504 | 49,831 | 6.64x | yes | | CHE | 9,969 | 61,373 | 6.16x | yes | | CAN | 7,669 | 44,869 | 5.85x | yes | | DNK | 8,513 | 46,312 | 5.44x | yes | | FRA | 7,224 | 38,516 | 5.33x | yes | | NLD | 8,931 | 47,474 | 5.32x | yes | | USA | 10,695 | 55,335 | 5.17x | yes | | BEL | 7,936 | 39,756 | 5.01x | yes | | NZL | 7,906 | 35,336 | 4.47x | yes | | GBR | 8,673 | 38,058 | 4.39x | yes |

Method

Long-run descriptive comparison. For each panel country with Maddison MPD2020 observations at both 1930 and the dataset's latest year (2018), compute the per-capita GDP ratio in 2011 PPP $. Aggregate across countries by:

  1. Population-weighted mean (weights: end-year population); this is the dispositive primary statistic.
  2. Equal-weighted country mean; reported as informative cross-check.
  3. Median; informative for skew.

Maddison MPD2020 is the only published source that covers 1930 for the full advanced-economy panel; the WDI series NY.GDP.PCAP.KD only starts in 1960. The spec's secondary WDI series is therefore not used in this primary test.

Caveats

  • Maddison ends in 2018; Keynes's 100-year horizon was 2030. Adding the further ~10-15 years of observed OECD growth at trend (~1.5%/yr) would raise the ratios by another factor of ~1.15-1.25 — does not change a SUPPORTED verdict, would only tighten margins.
  • 2011 PPP $ chaining tracks output, not subjective standard of living; Keynes's 'economic problem' framing is broader than GDP.
  • The hypothesis is descriptive: a ratio computation, not a causal claim. The degrowth reframing question (whether the growth imperative still binds given the threshold has been met) is downstream, not tested here.
  • Missing endpoint data: none.

Data

  • maddison:mpd2020 (vintage mpd2020@2026-04-26T134326Z.parquet)

Notes

Seeded from a degrowth claim that Keynes's 1930 4-8x per-capita projection has been met, inviting a reframing of the growth imperative. Long-run descriptive comparison; human review needed to choose anchor year and per-capita measure.

Authored framework. Read the transparency note.