IESET.
Hypotheses·distribution·tax_inequality_norway_wealth_tax_retention

Norway's continued retention of an annual wealth tax (formuesskatt) through 2024 — at rates of 0.85-1.1 percent on net wealth above NOK 1.7M — is associated with a top-1 wealth share trajectory that lies below the Nordic-ex-Norway synthetic counterfactual by at least 1 percentage point over 2010-2024, without a large register-based HNW emigration response prior to the 2022 rate increase.

The discriminating test is the synth-control gap on top-1 wealth share against the register-based emigration count.

PARTIALengine/runs/tax_inequality_norway_wealth_tax_retention

PARTIAL — mean_gap=+2.245, |gap|/pre_sd=3.7, p_perm=1; claim direction ambiguous

confidence cueThe result is useful, but not decisive. Treat it as a clue, not a settled conclusion.

policy briefMixed or noisy

In ordinary language

In plain terms, this asks whether norway wealth tax retention is actually linked to better or worse top 1pct wealth share from 2000 to 2024.

plain answer

The evidence is suggestive but not decisive. mean_gap=+2.245, |gap|/pre_sd=3.7, p_perm=1; claim direction ambiguous

why it matters

Distributional claims often sound morally clear but are empirically complex. This test asks whether the proposed channel explains real differences across places.

how the test works

It compares 5 country or place units from 2000 to 2024, using a synthetic control design, with fixed effects for country and year.

what was measured
What changed
  • Norway wealth tax retention
What we checked
  • Top 1pct wealth share
  • Top 10pct wealth share
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/tax_inequality_norway_wealth_tax_retention
1007550250200020122024NORSWEDNKFINISL
illustrative sketch · run pending
No coefficients yet. When the model fires, this chart will show top_1pct_wealth_share across 5 sampled countries over 2000–2024.
The shapes above are stylised — none of the lines are real data.
Placeholder for tax_inequality_norway_wealth_tax_retention. Published chart will be generated from engine/runs/tax_inequality_norway_wealth_tax_retention/chart_data.json.

Pre-registration

registration ordering unverified
first-spec commit 4c8ce8e · 2026-07-18T22:11:21Z
run generated · 2026-04-30T12:29:43Z
Run timestamp predates this path's first git-add commit (rebase, rename, or pre-git local run). Spec hash is still the path's first-add commit — not repository HEAD — but ordering is not a clean pre-registration proof.

Norway's continued retention of an annual wealth tax (formuesskatt) through 2024 — at rates of 0.85-1.1 percent on net wealth above NOK 1.7M — is associated with a top-1 wealth share trajectory that lies below the Nordic-ex-Norway synthetic counterfactual by at least 1 percentage point over 2010-2024, without a large register-based HNW emigration response prior to the 2022 rate increase. The discriminating test is the synth-control gap on top-1 wealth share against the register-based emigration count.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

SUPPORTED if Norway top-1 wealth share is at least 1 percentage point below Nordic-ex-NOR synthetic at the 2024 horizon AND register-based HNW outbound migration prior to 2022 averages below 0.5 percent of HNW stock per year. REFUTED if no detectable gap or migration rate above 1 percent per year.

formal test & threshold
test:      Synthetic-control with Nordic-ex-NOR donor pool (SWE, DNK, FIN, ISL).

Method

Template
synthetic_control
Fixed effects
country, year
Clustering
country
Sample
5 countries · 2000 – 2024
Evidence type
associational

Synthetic-control with Nordic-ex-NOR donor pool. Robustness with panel_fe across the Nordic block with NOR-specific indicator.

Data

VariableSourceTransform
top_1pct_wealth_share
outcome
owid:top-1-share-of-total-wealthtier 2
level
top_10pct_wealth_share
outcome
owid:top-10-share-of-total-wealthtier 2
level
norway_wealth_tax_retention
treatment
constructed:indicator = 1 for NOR, year >= 2000 (continuous regime)tier 5
indicator
log_real_gdp_per_capita
control
world_bank_wdi:NY.GDP.PCAP.KDtier 2
log
top_marginal_income_tax_rate
control
owid:top-marginal-income-tax-ratetier 2
level
trade_openness
control
world_bank_wdi:NE.TRD.GNFS.ZStier 2
level

● ready  · ● pending  · ● reconstruct-needed

Detailed result card

Result card — tax_inequality_norway_wealth_tax_retention

Verdict: PARTIAL — mean_gap=+2.245, |gap|/pre_sd=3.7, p_perm=1; claim direction ambiguous

Pre-registration

  • Claim: Norway's continued retention of an annual wealth tax (formuesskatt) through 2024 — at rates of 0.85-1.1 percent on net wealth above NOK 1.7M — is associated with a top-1 wealth share trajectory that lies below the Nordic-ex-Norway synthetic counterfactual by at least 1 percentage point over 2010-2024, without a large register-based HNW emigration response prior to the 2022 rate increase. The discriminating test is the synth-control gap on top-1 wealth share against the register-based emigration count.
  • Falsification rule: SUPPORTED if Norway top-1 wealth share is at least 1 percentage point below Nordic-ex-NOR synthetic at the 2024 horizon AND register-based HNW outbound migration prior to 2022 averages below 0.5 percent of HNW stock per year. REFUTED if no detectable gap or migration rate above 1 percent per year.

Synthetic-control estimate

  • shape: synth_did
  • treated_country: NOR
  • event_year: 2010
  • n_donors: 4
  • donor_weights (top): {'FIN': 0.5869, 'SWE': 0.2427, 'ISL': 0.1174, 'DNK': 0.053}
  • pre_rmse: 4.012613644194995
  • pre_period_sd: 0.6005636241620589
  • mean_post_gap: 2.244739748775394
  • end_period_gap: 2.89273327867825
  • post_period_years: [2010, 2024]
  • placebo_p_value: 1.0
  • n_placebos: 4
  • method: synthetic-control via NNLS, permutation inference

Variables resolved

  • owid:top-1-share-of-total-wealth → top_1pct_wealth_share (outcome, n=10811)
  • world_bank_wdi:NY.GDP.PCAP.KD → log_real_gdp_per_capita (controls, n=14066)
  • owid:top-marginal-income-tax-rate → top_marginal_income_tax_rate (controls, n=590)
  • world_bank_wdi:NE.TRD.GNFS.ZS → trade_openness (controls, n=10714)

Generated by scripts/run_synth_did.py at 2026-04-30T12:29:43+00:00

Notes

Tax-inequality candidate, swarm-S6 batch 2. Pairs with the French case for cross-country wealth-tax retention vs abolition contrast.

Authored framework. Read the transparency note.