DATE
PARALLEL RATE
OFFICIAL RATE
Parallel Rate Index
Official Rate  Index
CPI local currency
CPI USA
i_loc (per annum)
i_usd (per annum)
(officialrateindex*cpi_us)/cpi_loc
i_usd/12
i_loc/12
(parallrateindex/L1.parallelrateindex)-1
1+r_usd-(1+r_loc)/(1+d)
R*(1+d)
Country-specific commodity price index