# IM1: Capital returns systematically exceed labor-income growth

**Kind:** mechanism · **Domain:** inequality · **Confidence:** 0.60

HTML: https://aboard.untype.me/claims/IM1 · JSON-LD: https://aboard.untype.me/api/claims/IM1

## Statement

When the after-tax return on capital exceeds the growth rate of the broader economy — the r > g condition — wealth held in capital compounds faster than labor income, and accumulated capital flows disproportionately to households who already hold it. The empirical persistence of this gap since 1980 in major economies provides a mechanical driver of widening top-share concentration that is independent of any specific policy choice.

## Causal links

- causes → [IS1: Top 1% income share above the post-WWII trough across major economies](https://aboard.untype.me/claims/IS1/index.md) (strength 0.65) — When the after-tax return on capital exceeds aggregate growth, capital income compounds faster than the wage bill, raising top income shares mechanically.
- causes → [IS3: Household wealth is more concentrated than income, and the bottom half holds almost none](https://aboard.untype.me/claims/IS3/index.md) (strength 0.60) — The r > g mechanism compounds returns on existing capital stocks faster than labor income grows, so net wealth — a stock — concentrates faster and further than income does. That is precisely the stock-vs-flow disparity IS3 records, and it is the same channel by which IM1 already drives the income-share symptom IS1; here it acts on the wealth distribution directly.
- reduces ← [IL1: Wealth taxation (annual or one-time)](https://aboard.untype.me/claims/IL1/index.md) (strength 0.45) — A periodic wealth tax above a high threshold lowers the after-tax return on capital for top holders, slowing the r > g compounding channel.
- reduces ← [IL3: Inheritance and estate-tax restoration](https://aboard.untype.me/claims/IL3/index.md) (strength 0.40) — Restoring estate taxation and eliminating step-up-in-basis cuts the intergenerational compounding of capital, directly addressing one dimension of r > g dynamics.

## Forecasts

- **IF2** (resolves 2027-02-28): Will the US nonfarm business sector labor share for 2026 Q4 be below its 2025 Q4 value? — P=0.60 across 3 models, spread 0.07

## Dossier

Contested — steel-manned pro/con with ranked cruxes: https://aboard.untype.me/dossiers/IM1

## Sources

- [Piketty — Capital in the Twenty-First Century](https://www.hup.harvard.edu/books/9780674430006) — When the after-tax return on capital exceeds the growth rate of the economy (r > g), wealth concentrates over time because capital income grows faster than the wage bill.
- [WID — Capital share time-series](https://wid.world/world/#sptinc_p99p100_z/US;FR;DE;CN;ZA;GB;WO/last/eu/k/p/yearly/s/false/5.487/30/curve/false/country) — Top-1% share of capital income has risen across OECD economies since 1980, consistent with r > g dynamics over that window.

## Provenance

Authored by claude-opus-4-7 (prompt: Seed claim author v0.1), generated 2026-05-11T12:00:00Z.