How do I convert from one currency to another if only the country code is given?

Question

I have a data set something like this:

value <- data.frame(Country = c('AUS', 'AUT', 'GBR'), amount = c(200, 150, 300))

every amount is given in the respectives country currency. So 200 in Aus. Dollar, 150 in Euro and 300 in Pound. What I want at the end is every number converted to the same currency, let's say Euro.

I already found something like library(quantmod) but this only helps with conversion. So I would need to get the currency first only from the country code.

Any Ideas?

Answer 1

We can use the countrycode package to convert ISO3 country codes into the relevant ISO4217 currency codes, then use priceR to use that to convert each currency to a single one, Euros in this example.

Let's first get the currency code.

library(countrycode)
library(priceR)

value$currency_code <- countrycode(value$Country, "iso3c", "iso4217c")
value
#>   Country amount currency_code
#> 1     AUS    200           AUD
#> 2     AUT    150           EUR
#> 3     GBR    300           GBP

We can then get all the latest Euro exchange rates.

e_df <- exchange_rate_latest("EUR")
#> Daily EUR exchange rate as at end of day 2022-01-18 GMT

head(e_df)
#>     currency one_eur_is_equivalent_to
#> 1        AED                 4.184241
#> 2        AFN               119.337926
#> 3        ALL               122.074346
#> 4        AMD               547.591037
#> 5        ANG                 2.052008
#> 6        AOA               611.091441

Last, let's bring that the exchange into our data frame and calculate the amounts in Euros.

value$exchange_euro <- e_df$one_eur_is_equivalent_to[match(value$currency_code, e_df$currency)]
value$amount_euro <- value$amount / value$exchange_euro
value
#>   Country amount currency_code exchange_euro amount_euro
#> 1     AUS    200           AUD      1.584396    126.2311
#> 2     AUT    150           EUR      1.000000    150.0000
#> 3     GBR    300           GBP      0.836131    358.7955