# Choosing conversion factors

## The source argument

Use the source argument in convertGDP to control the source of the underlying conversion factors (GDP deflators, MERs and PPPs). This can be a user-defined object or one of the sources shipped with the package.

## User-defined ‘source’ objects

Any tibble with columns:

• “iso3c” (character),
• “year” (numeric),
• “GDP deflator” (numeric),
• “MER (LCU per US$)” (numeric), • “PPP conversion factor, GDP (LCU per international$)” (numeric)

can be used as a source of conversion factors.

library(GDPuc)

my_gdp <- tibble::tibble(
iso3c = "USA",
year = 2010:2014,
value = 100:104
)

my_custom_source <- tibble::tibble(
iso3c = "USA",
year = 2010:2014,
"GDP deflator" = seq(1, 1.1, 0.025),
"MER (LCU per US$)" = 1, "PPP conversion factor, GDP (LCU per international$)" = 1,
)
print(my_custom_source)
#> # A tibble: 5 × 5
#>   iso3c  year GDP deflator MER (LCU per US$) PPP conversion factor, GDP (L…¹ #> <chr> <int> <dbl> <dbl> <dbl> #> 1 USA 2010 1 1 1 #> 2 USA 2011 1.02 1 1 #> 3 USA 2012 1.05 1 1 #> 4 USA 2013 1.08 1 1 #> 5 USA 2014 1.1 1 1 #> # … with abbreviated variable name #> # ¹​PPP conversion factor, GDP (LCU per international$)

convertGDP(
gdp = my_gdp,
unit_in = "constant 2010 LCU",
unit_out = "constant 2014 Int$PPP", source = my_custom_source, verbose = TRUE ) #> ℹ Converting GDP with conversion factors from user_provided: #> constant 2010 LCU → constant 2014 LCU #> 2014 value of base 2010 GDP deflator in (constant 2014 LCU per constant 2010 #> LCU) used: #> USA: 1.1 #> constant 2014 LCU → constant 2014 Int$PPP
#> 2014 PPP conversion factor in (LCU per international $) used: #> USA: 1 #> # A tibble: 5 × 3 #> iso3c year value #> <chr> <int> <dbl> #> 1 USA 2010 110 #> 2 USA 2011 111. #> 3 USA 2012 112. #> 4 USA 2013 113. #> 5 USA 2014 114. ## Shipped ‘sources’ There are two source options shipped with the package, wb_wdi and wb_wdi_linked, with wb_wdi set as the default. Pass the name of a shipped source to the source argument to use it. convertGDP( gdp = my_gdp, unit_in = "constant 2010 LCU", unit_out = "constant 2014 Int$PPP",
verbose = TRUE
)
#> ℹ Converting GDP with conversion factors from wb_wdi_linked:
#> constant 2010 LCU → constant 2014 LCU
#> 2014 value of base 2010 GDP deflator in (constant 2014 LCU per constant 2010
#> LCU) used:
#> USA: 1.07831211972599
#> constant 2014 LCU → constant 2014 Int$PPP #> 2014 PPP conversion factor in (LCU per international$) used:
#> USA: 1
#> # A tibble: 5 × 3
#>   iso3c  year value
#>   <chr> <int> <dbl>
#> 1 USA    2010  108.
#> 2 USA    2011  109.
#> 3 USA    2012  110.
#> 4 USA    2013  111.
#> 5 USA    2014  112.

Use the function print_source_info to print information on a specific, or all available sources.

print_source_info("wb_wdi")
#> ── wb_wdi ──────────────────────────────────────────────────────────────────────
#> → Origin: The World Bank's World Development Indicator Database
#> → Html: https://databank.worldbank.org/source/world-development-indicators
#> → Note: Uses the standard deflator.
#> ────────────────────────────────────────────────────────────────────────────────
print_source_info()
#> ℹ Sources available:
#> ── wb_wdi ──────────────────────────────────────────────────────────────────────
#> → Origin: The World Bank's World Development Indicator Database
#> ────────────────────────────────────────────────────────────────────────────────
Use the ::: operator to take a closer look at sources shipped with GDPuc.
GDPuc:::wb_wdi