Convert a present-day value to its historical equivalent

Takes a monetary amount from a recent year and returns what it would have been worth in a specified historical year, using bundled CPI data sourced from the World Bank Development Indicators. Supports GBP, AUD, USD, EUR, CAD, JPY, CNY, CHF, NZD, INR, KRW, BRL, and NOK.

Usage

historical_value(amount, to_year, currency, from_year = NULL, round = 2)

Arguments

amount

Numeric (scalar or vector). The monetary amount(s) in the reference year.

to_year

Integer. The historical year to convert back to.

currency

Character. Currency code ("GBP", "AUD", "USD", "EUR", "CAD", "JPY", "CNY", "CHF", "NZD", "INR", "KRW", "BRL", "NOK") or country name ("Australia", "United States", etc.) — case-insensitive.

from_year

Integer. The year the amount is from. Defaults to the latest year available in the data.

round

Integer or NULL. Number of decimal places to round to (default 2). Use NULL for full precision.

Value

A numeric value (or vector) representing the historical equivalent amount.

See also

Other CPI adjustment: adjust_inflation()

Examples

# What would £100 today have been worth in 1963?
historical_value(100, 1963, "GBP")
#> [1] 4.68

# What would USD 500 in 2020 have been worth in 1980?
historical_value(500, 1980, "USD", from_year = 2020)
#> [1] 159.2