Across 20 selected economies with both values in 2023, the Pearson association is 0.88.

Decision supported: Whether two published measures move together across the selected economies in one common year.

Required inputs: Two indicator definitions, one common comparison year, a fixed economy set, and optional population for marker area.

1. Align both indicators to one year.

2. Drop only pairs without both values and report the resulting sample.

3. Encode the third measure by marker area, never radius.

4. Label selected points, not every point.

5. Describe association only; do not claim causation.

Failure modes: Country-level association can be driven by omitted variables. Small selected samples are sensitive to the economy set. Current-US-dollar income is not a purchasing-power measure.