IESET.
Hypotheses·distribution·tax_inequality_south_africa_property_tax_burden

Post-apartheid South African tax structure (top marginal income rate raised to 45 percent in 2017, capital-gains inclusion ratio raised 2012 + 2016, recurring property-tax effective burden via municipal rates) produced a measurable reduction in the South African top-1 pretax income share over 1995-2024 vs SADC synthetic comparator pool, with the recurring property-tax channel contributing more than the marginal-income-rate channel to the distributional effect.

The discriminating test is the channel decomposition.

INCONCLUSIVEengine/runs/tax_inequality_south_africa_property_tax_burden

INCONCLUSIVE_DATA_PENDING — insufficient pre-period coverage (years=5, donors=0)

confidence cueResult card produced; verdict unclassified.

policy briefCoverage too thin

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

This test cannot make a firm call yet. insufficient pre-period coverage (years=5, donors=0)

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 1995 to 2024, using a synthetic control design, with fixed effects for country and year.

what was measured
What changed
  • Zaf post apartheid tax regime
  • Top marginal income tax rate
What we checked
  • Top 1pct pretax income share
  • Inequality disposable income
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_south_africa_property_tax_burden
1007550250199520102024ZAFNAMBWAZMBMOZ
illustrative sketch · run pending
No coefficients yet. When the model fires, this chart will show top_1pct_pretax_income_share across 5 sampled countries over 1995–2024.
The shapes above are stylised — none of the lines are real data.
Placeholder for tax_inequality_south_africa_property_tax_burden. Published chart will be generated from engine/runs/tax_inequality_south_africa_property_tax_burden/chart_data.json.

Pre-registration

registration ordering unverified
first-spec commit 4c8ce8e · 2026-07-18T22:11:21Z
run generated · 2026-05-04T12:34:35Z
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.

Post-apartheid South African tax structure (top marginal income rate raised to 45 percent in 2017, capital-gains inclusion ratio raised 2012 + 2016, recurring property-tax effective burden via municipal rates) produced a measurable reduction in the South African top-1 pretax income share over 1995-2024 vs SADC synthetic comparator pool, with the recurring property-tax channel contributing more than the marginal-income-rate channel to the distributional effect. The discriminating test is the channel decomposition.

Falsification criterion — what would disprove this

set before the run · honoured after

This hypothesis is considered falsified if:

SUPPORTED if South African top-1 share falls by at least 1.0 percentage point 1995-2024 vs SADC synth control AND property-tax channel decomposition exceeds marginal-income-rate channel at p<0.10. REFUTED if no detectable gap or property-tax channel is less than half the marginal-rate channel at p<0.10.

formal test & threshold
test:      Synthetic-control with SADC donor pool (NAM, BWA, ZWE, MOZ, ZMB), treated ZAF 1995, plus channel-decomposition panel-FE.

Method

Template
synthetic_control
Fixed effects
country, year
Clustering
country
Sample
5 countries · 1995 – 2024
Evidence type
associational

Synthetic-control with SADC donor pool. Channel-decomposition via panel_fe_decomposition robustness.

Data

VariableSourceTransform
top_1pct_pretax_income_share
outcome
owid:top-1-share-of-total-incometier 2
level
gini_disposable_income
outcome
world_bank_wdi:SI.POV.GINItier 2
level
zaf_post_apartheid_tax_regime
treatment
constructed:indicator = 1 for ZAF, year >= 1995tier 5
indicator
top_marginal_income_tax_rate
treatment
owid:top-marginal-income-tax-ratetier 2
level
log_real_gdp_per_capita
control
world_bank_wdi:NY.GDP.PCAP.KDtier 2
log
trade_openness
control
world_bank_wdi:NE.TRD.GNFS.ZStier 2
level

● ready  · ● pending  · ● reconstruct-needed

Detailed result card

Result card — tax_inequality_south_africa_property_tax_burden

Verdict: INCONCLUSIVE_DATA_PENDING — insufficient pre-period coverage (years=5, donors=0)

Pre-registration

  • Claim: Post-apartheid South African tax structure (top marginal income rate raised to 45 percent in 2017, capital-gains inclusion ratio raised 2012 + 2016, recurring property-tax effective burden via municipal rates) produced a measurable reduction in the South African top-1 pretax income share over 1995-2024 vs SADC synthetic comparator pool, with the recurring property-tax channel contributing more than the marginal-income-rate channel to the distributional effect. The discriminating test is the channel decomposition.
  • Falsification rule: SUPPORTED if South African top-1 share falls by at least 1.0 percentage point 1995-2024 vs SADC synth control AND property-tax channel decomposition exceeds marginal-income-rate channel at p<0.10. REFUTED if no detectable gap or property-tax channel is less than half the marginal-rate channel at p<0.10.

Synthetic-control estimate

  • Error: insufficient pre-period coverage (years=5, donors=0)

Variables resolved

  • owid:top-1-share-of-total-income → top_1pct_pretax_income_share (outcome, n=3294)
  • world_bank_wdi:SI.POV.GINI → gini_disposable_income (outcome, n=2430)
  • constructed: indicator = 1 for ZAF, year >= 1995 → zaf_post_apartheid_tax_regime (treatment, n=150)
  • owid:top-marginal-income-tax-rate → top_marginal_income_tax_rate (treatment, n=590)
  • world_bank_wdi:NY.GDP.PCAP.KD → log_real_gdp_per_capita (controls, n=14066)
  • world_bank_wdi:NE.TRD.GNFS.ZS → trade_openness (controls, n=10714)

Generated by scripts/run_synth_did.py at 2026-05-04T12:34:35+00:00

Notes

Tax-inequality candidate, swarm-S6 batch 6. The wealth-tax debate is active in South Africa; this hypothesis tests the alternative claim that recurring property-tax already does substantial distributional work.

Authored framework. Read the transparency note.