Here is comparison of Paper Money and Banknote.
They have same maintenance costs from number of cities and distance to palace.
Banknote is unlocked in Medieval and Paper Money is unlocked in Renaissance.
Banknote has +5% and Paper Money has -10% foreign trade yield.
Paper Money has 20% and Banknote has 5% inflation.
Both of them have +5% to commerce.
Paper Money needs building to get 5% gold boost, and Banknote gives it automatically, and it has gold bonus from banks.
Both of them can hurry things for gold.
Maybe Banknote and Paper Money techs requirements were switched?
Techs unlocking those civics are 3 grids apart from each other.
This means Paper Money may as well not exist.