Research

Maddison Project Database catalog - countries, regions, release metadata

Changed on

Discovery endpoint for the Maddison Project Database (MPD2023). Returns publication metadata (release version, DOI, DataverseNL URL, publication date), the 169 countries in the workbook with their ISO 3166-1 alpha-3 codes and per-country first/last year of observation, the 8 analytical regions used by the Maddison Project with their stable slugs, the two variables (gdppc, pop), and the overall year range (1 AD through 2022). Use this before calling /country/{iso3}, /regional, or /top to confirm ISO3 codes and available year ranges. Published by Bolt and van Zanden at the University of Groningen under CC BY 4.0; full citation in every response envelope.

get/api/v1/research/maddison/catalog

Request

  • Base URL: https://sugra.ai
  • URL: https://sugra.ai/api/v1/research/maddison/catalog
  • Auth: API key in header x-api-key

Response

Catalog listing with release metadata, country coverage, region list, and variable dictionary.

Example response

{
  "data": {
    "release": {
      "version": "MPD2023 v1.0",
      "doi": "10.34894/INZBF2",
      "published": "2024-04-26T00:00:00Z",
      "url": "https://dataverse.nl/dataset.xhtml?persistentId=doi:10.34894/INZBF2",
      "file": "mpd2023_web.xlsx"
    },
    "countries": [
      {
        "iso3": "USA",
        "country": "United States",
        "region": "Western Offshoots",
        "region_slug": "western-offshoots",
        "first_year": 1650,
        "last_year": 2022
      }
    ],
    "country_count": 169,
    "regions": [
      {
        "slug": "western-europe",
        "name": "Western Europe"
      }
    ],
    "region_count": 8,
    "variables": [
      {
        "id": "gdppc",
        "label": "GDP per capita",
        "unit": "2011 international dollars (PPP)"
      }
    ],
    "year_range": {
      "min": 1,
      "max": 2022
    }
  },
  "meta": {
    "endpoint": "/api/v1/fred/us/cpi",
    "data_time": "2026-04-16T14:30:00Z",
    "response_time": "2026-04-16T14:30:12Z",
    "provider": "Sugra API v1.0.1",
    "data_age_days": 8.532,
    "source": "sugra_crypto",
    "attribution": "Short interest and Reg SHO daily short volume data is owned by and sourced from FINRA (Financial Industry Regulatory Authority).",
    "fallback_chain": [
      "sugra_crypto",
      "sugra_finance"
    ],
    "stale_since": "2026-09-08T12:00:00Z",
    "period": "2026-Q1",
    "notes": "the UKMTO report behind these counts is dated 2026-08-21 and is 11 days old"
  }
}

Changes