External Inputs for Modeling the Economy

GCAM’s economic inputs include information on population and income. These inputs are required for each geopolitical region and historical year.

External Inputs

Description

Table 1: External inputs used for economics¹

Name	Description	Type	Source	Resolution	Unit
Population	Population by country and year, used for 1700-1900	External data set	Maddison	Country/region and year	Thousands
Population	Population by country and year, used for 1950-2015	External data set	UN	Country/region and year	Thousands
Population	Population by country and year, used for 2015-2100	External data set	SSP database	Country and year	Thousands
GDP	Historical GDP used for most countries for GDP prior to 2015	External data set	USDA	Country and year	billion US$2010/yr (MER)
GDP	Historical GDP used for remaining countries for GDP prior to 2015	External data set	World Bank	Country and year	billion US$2010/yr (MER)
GDP growth rate	Near-term growth rate of GDP (2015-2024)	External data set	IMF	Country and year	%
GDP	GDP by country and year, used for 2025-2100	External data set	SSP database, OECD Model	Country and year	billion US$2005/yr (PPP)

1: Note that this table differs from the one provided on the Economy Modeling Page in that it only lists external inputs to the economics module (either data sources or assumptions). Additionally, the units listed are the units of the raw inputs, rather than the units the GCAM requires.

Note that for the Shared Socioeconomic Pathways (SSPs), different inputs are used for some variables. See SSPs for more information.

Input Data

Population

Historical population is provided in Maddison_population.csv (used for 1700-1900) and UN_popTot.csv (used for 1950-2015).

Future population is provided in SSP_database_v9.csv.

GDP

Historical GDP is provided in USDA_GDP_MER.csv (used through 2015).

Near-term GDP growth rates are provided in IMF_GDP_growth.csv.

Future GDP is provided in SSP_database_v9.csv.