Research

Variable dictionary, methodology, and citation policy

Changed on

Documentation endpoint for the Maddison Project Database. Returns the two variables (GDP per capita and population) with their units and methodology notes, the 8 regional slugs and their canonical names, the release metadata (version, DOI, DataverseNL URL), the CC BY 4.0 citation policy including the special rule requiring per-country source citations for analyses covering fewer than 12 countries, and a short and full academic citation string. Published by Bolt and van Zanden at the University of Groningen under CC BY 4.0.

get/api/v1/research/maddison/definitions

Request

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

Response

Variable dictionary, region list, methodology, and citation policy.

Example response

{
  "data": {
    "variables": [
      {
        "id": "gdppc",
        "label": "GDP per capita",
        "unit": "2011 international dollars (PPP)"
      }
    ],
    "regions": [
      {
        "slug": "western-europe",
        "name": "Western Europe"
      }
    ],
    "citation_short": "Maddison Project Database (Bolt & van Zanden, University of Groningen, CC BY 4.0)",
    "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"
    },
    "known_historical_codes_absorbed": [
      "SUN",
      "YUG",
      "CSK",
      "SCG"
    ]
  },
  "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