... something which can be aggregated, a monetary amount, while inflation and/or "real" GDP (whichever comes first ... with a market basket it is the inflation index that comes first and "real" values are imputed from that, with a deflator it is the other way around) are an effort to provide a simple index value to summarize a relationship between vector quantities.

Keynes' basic argument for working in terms of nominal amounts and employment was that the ability of a person to work as unskilled labor if need be provided a connection between various specialized and more restricted skilled labor markets in terms of their renumeration as a multiple of the wage of unskilled labor, providing a quantity that could be aggregated with greater justification than the vector of the amount produced of each and every different type of final product for sale in the economy.


I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.