Relative Wealth Signals for the "Renegade" G20 Economies: A Methodological Investigation
Working brief — StratMac Research Library
1. Purpose and scope
StratMac publishes a Global Wealth per Capita card for each G20+ economy: the country's wealth-per-adult divided by U.S. GDP-per-capita. Three economies have refused to yield an honest value of that quantity from any source we can verify — Turkey, Argentina, and the European Union aggregate (which shares the same data dependency). Their cards were unpublished in 2026-08 after the per-adult series they were built on was found to carry a ~10³–10⁴× unit-scale error that produced impossible, reader-visible spikes ("crashes" of 39×, 1005×, 22.9× vs. U.S. GDP-per-cap).
This brief documents, for the record, every source we evaluated and every USD-conversion method we attempted, the empirical validation we ran against trusted anchors, the structural reason each failed, and why we chose to leave these cards unpublished rather than ship a synthetic series.
2. The target quantity and why it compounds a known error
The published quantity is
WEALTCAP_c(t) = W_c(t) / USGDPcap(t)
where W_c(t) is country c's mean household wealth per adult in current U.S. dollars at year t, and USGDPcap(t) is U.S. GDP per capita. The numerator crosses currencies for every non-U.S. country, so the entire signal depends on a defensible local-currency → USD conversion of a multi-decade wealth series.
The 10³–10⁴× error in Turkey/Argentina originated exactly here: a local-currency wealth series was divided by a currency-incompatible dollar rate, inflating (or collapsing) the ratio by orders of magnitude. Rebuilding the card therefore required, first, a source with trustworthy per-year USD wealth-per-adult; we found none that is both continuous and USD and verifiable for these economies — and the reasons are specific and informative.
3. Sources evaluated (complete list)
| # | Source | Continuous (per-year)? | USD? | Verifiable openly? | Coverage | Verdict |
|---|---|---|---|---|---|---|
| A | UBS / Credit Suisse Global Wealth Databook | ✗ (snapshot years end-2000, end-2023) | ✓ | ✗ PDFs bot-blocked (403/HTML shell) | global | authoritative USD but not a time series |
| B | WID (World Inequality Database, wid.world) | ✓ (annual, ~1800–2025) | ✗ (local currency / PPP) | ✓ (bulk CSV staged) | global | continuous but currency-native |
| C | Wikipedia "List of countries by wealth per adult" (collates UBS) | ✗ (single-year end-2022) | ✓ | ✓ (HTML table) | global | USD but one year only |
| D | datahub.io rehost | ✗ | ✓ | partial (Vercel 404 on raw CSV) | 20 countries | insufficient |
| E | IMF WEO / World Bank ICP (PPP) | ✓ (annual) | ~ (PPP units) | ✓ | global | PPP, not market USD |
Key structural fact: WID is the only source that gives continuous per-year wealth-per-adult, and it does so only in local currency (or WID's own PPP construct). Every other continuous source is PPP or not USD; every USD source is a snapshot. No single verifiable source provides continuous USD. The gap must be bridged.
4. Methods attempted, with empirical validation
We staged WID's full bulk dataset (wid_all_data.zip, 882 MB; land in data_source/wid/, 2026-07-25 release) and worked from the raw per-country CSVs. The correct variable is ahweali992 = wealth per adult, full population (the 999 suffix is per-capita — a trap we confirmed and rejected). We validated every conversion against trusted UBS 2022 mean wealth-per-adult anchors (USD): US 551,347 · DE 256,179 · CH 685,226 · CN 75,000 · TR 17,578 · AR 13,323 · BR 16,700 · RU 26,896.
4.1 Attempt 1 — Single-year market FX
Divide WID local-currency wealth by a current-year market FX rate. Result: reproduces stable-currency economies (US 0.98×, CN 1.03×, DE 0.85×) but over-shoots high-inflation economies wildly (TR 6.1×, AR 41× at 2022). Cause: the wealth series is a real/deflated LCU construct; a nominal current FX is unit-mismatched.
4.2 Attempt 2 — Single-year WID PPP converter (xlcuspi999)
Divide by WID's own LCU-per-PPP-USD. Result: similar failure (TR 20×, AR 89× at 2022). Same root cause: PPP converter is nominal-base, not matched to the real wealth series.
4.3 Attempt 3 — Per-year market FX (xlcusxi999) and per-year PPP (xlcuspi999)
Use each year's own converter, paired with each year's wealth value. Result: still mis-stated for high-inflation countries — TR 6–20×, AR 41–89×, BR 2.6×, RU 2.8× off target; stable-currency CN/US/DE/CH/FR land within 0.85–1.9×. The FX history is fully available; it simply does not reconcile with the wealth base for these economies.
4.4 The structural diagnosis (why 4.1–4.3 fail)
For high-inflation economies, WID's ahweali992 is a real (price-deflated) local-currency series. Evidence — Turkey: nominal wealth moves only 945k → 1.8M (1990→2023), while the TRY/USD FX explodes 0.003 → 39 over the same window. A real-value numerator divided by a nominal-exchange denominator is dimensionally inconsistent. The handful of economies whose nominal FX closely tracks their real price level (US, DE, CH, CN, FR) happen to convert cleanly; the high-inflation ones cannot. This is precisely the error family that corrupted the original Turkish/Argentine files at ~10³–10⁴×.
4.5 Attempt 4 — FX-free within-currency ratio (not deployed)
Form W_c(t) / GDP_c(t) — country wealth-per-adult ÷ own GDP-per-adult, both real LCU, both from WID. This is the only conversion that is provably currency-consistent for every country, because the currency cancels identically in numerator and denominator. It is statistically sound and corruption-proof by construction. Not adopted because it redefines the card from "wealth vs US GDP" to "wealth vs own GDP" — a change of semantics we regard as a reader-facing methodological decision, not one an implementation should make unilaterally.
5. Findings (encapsulated)
- No verifiable, openly-accessible, continuous-per-year USD wealth-per-adult source exists for Turkey, Argentina, or the EU aggregate. This is a genuine gap in the public statistical infrastructure, not a gap in StratMac's tooling.
- WID's wealth-per-adult is real-value local currency, and for high-inflation economies its conversion to USD via any nominal FX or PPP rate is dimensionally invalid. We reproduced the original ~10⁴× corruption mechanism in controlled attempts.
- Stable-currency economies convert cleanly from WID (validated 0.85–1.9× against UBS), which is why 35 of 38 global-wealth cards are sound and stay published.
- There is a provably-correct alternative — the within-currency wealth/GDP ratio — but it changes the card's meaning and is therefore held for an explicit methodological decision rather than silently substituted.
- Publishing nothing is the correct near-term state for these three cards. It is preferable to a number that is wrong by one or two orders of magnitude, and the site's integrity rests on readers being able to trust the cards we do show.
6. Decision and disposition
- Turkey (
G20_TUR), Argentina (G20_ARG): are unpublished. Their prior data is withdrawn. Restoration is gated on a verifiable currency bridge (the within-currency ratio being the only mechanism shown to be structurally sound) or a new open USD source. - EU aggregate (
G20_EUU): is unpublished; it carries the same data dependency and will be restored by the same path. - Brazil / Russia / Romania: their visible (post-2000) windows are plausible (2.4×, 4.8×, 2.2×), so their cards stay up. Their pre-2000 values carry the same unit-scale corruption history, which is invisible to readers; this is logged and flagged for correction by any future regenerated pipeline, but is not a reader-facing defect today.
- The
sm-card-corruption-watchdog(daily, script-only) remains active and will alert if any visible-window value ever exceeds 15× or falls below 0.02× of U.S. GDP-per-cap, or spikes/crashes steeply year-over-year.
7. Reopening criteria and open questions
Those who wish to revisit this should know what would change our conclusion:
- A new continuous USD source (official-currency WID variant, or a documented real-FX deflation of the WID wealth series validated against the UBS anchors at both end-2000 and end-2023) would permit faithful restoration of the original card semantics.
- An explicit decision to adopt the within-currency ratio (wealth ÷ own GDP) would let all three return immediately with currency-consistent data.
- Open methodological question for the advisory: Is "wealth ÷ own GDP" a different, acceptable signal, or is only "wealth ÷ US GDP-per-cap" acceptable? This is the crux; the data cannot decide it, only a policy decision can.
8. Sources of primary data cited
- WID, World Inequality Database, full bulk export (2026-07-25), var
ahweali992,xlcusxi999,xlcuspi999. - UBS / Credit Suisse, Global Wealth Report / Databook (2022, 2023, 2024 editions), mean wealth per adult (USD).
- Wikipedia, List of countries by wealth per adult (UBS-collated table, end-2022) — used as the anchor table.
This brief is part of the StratMac data-correctness policy record.