---
title: "Regional GDP per capita and population for all 8 Maddison regions"
method: GET
path: "/api/v1/research/maddison/regional"
tags: ["Research"]
---

# Regional GDP per capita and population for all 8 Maddison regions

`GET /api/v1/research/maddison/regional`

Returns Maddison Project regional aggregates: GDP per capita in 2011 international dollars (PPP) and population in thousands of people for each of the 8 analytical regions (East Asia, Eastern Europe, Latin America, Middle East and North Africa, South and South East Asia, Sub-Saharan Africa, Western Europe, Western Offshoots). Use the `region=` query to restrict the response to a single region. The Maddison groups the US, Canada, Australia, and New Zealand into `Western Offshoots`; `north-america` is accepted as an alias for that bloc. Regional GDP per capita is a population-weighted average of member country values. Cells are null where not every member country reports for that year. Pre-1950 observations follow the Maddison milestone grid; annual from 1950 through 2022. Published under CC BY 4.0 by Bolt and van Zanden at the University of Groningen.

## Query parameters

- `region` string, nullable — Optional region slug. Accepted: `western-europe`, `eastern-europe`, `north-america` (alias for Western Offshoots), `western-offshoots`, `latin-america`, `mena`, `sub-saharan-africa`, `east-asia`, `south-and-southeast-asia`. Omit to return all 8 regions.
- `start_year` integer, nullable — Inclusive start year (integer). Regional series begins at 1820.
- `end_year` integer, nullable — Inclusive end year (integer). Defaults to 2022.

## Response `200`

One block per region with year-ordered gdppc and pop observations.

- EnvelopeMaddisonRegionalPayload
  - `data` MaddisonRegionalPayload, required — Regional aggregates across all 8 MPD regions, or one filtered region.
    - `regions` MaddisonRegionalBlock[], required — One block per region. If the caller filters with `region=`, the list contains a single block.
      - `region` string, required — Region label as spelled in the upstream workbook.
      - `region_slug` string, required — Stable slug form.
      - `observations` MaddisonRegionalObservation[], required — Year-ordered observations for this region.
        - `year` integer, required — Observation year.
        - `gdppc` number, nullable — Population-weighted regional GDP per capita in 2011 international dollars (PPP). Null where not every member country reports for this year.
        - `pop` number, nullable — Regional population, thousands of people.
      - `count` integer, required — Number of observations returned for this region.
    - `region_count` integer, required — Number of region blocks in this response.
    - `start_year` integer, nullable — Inclusive start year applied, or null if unbounded.
    - `end_year` integer, nullable — Inclusive end year applied, or null if unbounded.
  - `meta` SugraMeta, required — Metadata attached to every /api/v1/* response envelope.
    - `endpoint` string, required — Requested endpoint path.
    - `data_time` string, required — ISO 8601 UTC timestamp of the source data, not of the request.
    - `response_time` string, required — ISO 8601 UTC timestamp when this response was produced.
    - `provider` string, required — API name and version.
    - `source` string, nullable — Identifier of the primary upstream source used for this response.
    - `attribution` string, nullable — Human-readable attribution mandated by an upstream source (e.g. a securities regulator or self-regulatory organization). Present only on responses whose source requires the owner and source to be clearly identified. Do not remove or alter it when using the response.
    - `fallback_used` boolean, nullable — True when the primary source failed and a fallback produced the data.
    - `fallback_chain` string[], nullable — Ordered list of sources attempted, in the order they were tried.
    - `cached` boolean, nullable — True when this response was served from the internal cache.
    - `stale` boolean, nullable — True when the cached response was returned after the upstream rate-limited or errored. Clients can use this to detect degraded data.

## Other responses

- `401` — Missing or invalid `x-api-key` header.
- `422` — Validation Error
- `429` — Daily rate limit exceeded. Check `X-RateLimit-Reset` for the next window.
- `503` — Upstream source is temporarily unavailable. Retry after a short delay.

---

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