Long-run GDP and population time series for one country

GET

/api/v1/research/maddison/country/{iso3}

Last modified:2026-05-10 09:22:39

Maintainer:Not configured

OperationId:research_maddison_country_iso3

Returns the full Maddison Project Database time series for one country: GDP per capita in 2011 international dollars (PPP) and population in thousands of people, one row per year from the country's earliest observation to 2022. Country-year cells with no observation return null for both fields (the Maddison panel is 17.8% dense on average - some countries only have data from 1820 onwards, a few Western European cores reach back to year 1 AD). For regional aggregates use /regional; for the world aggregate use /world. Published under CC BY 4.0 by Bolt and van Zanden at the University of Groningen.

Request

Authorization

API Key

Add parameter in header

x-api-key

Example:

x-api-key: ********************

Path Params

Query Params

Header Params

Request Code Samples

Shell

JavaScript

Java

Swift

PHP

Python

HTTP

Objective-C

Ruby

OCaml

Dart

curl --location '/api/v1/research/maddison/country/USA?start_year=1820&end_year=2022' \
--header 'x-api-key: <api-key>'

Responses

🟢200

application/json

Year-ordered observations with gdppc (2011 int$) and pop (thousands) plus country metadata.

Bodyapplication/json

Example

{
    "data": {
        "iso3": "USA",
        "country": "string",
        "region": "string",
        "region_slug": "string",
        "observations": [
            {
                "year": 2022,
                "gdppc": 0,
                "pop": 0
            }
        ],
        "count": 775,
        "start_year": 0,
        "end_year": 0
    },
    "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",
        "source": "string",
        "fallback_used": true,
        "fallback_chain": [
            "string"
        ],
        "cached": true
    }
}

🟠401

🟠422

🟠429

🔴503

Modified at 2026-05-10 09:22:39

Maddison Project Database catalog - countries, regions, release metadata

World GDP per capita and population aggregate time series