If I have series(variable) of FDI % of GDP with negative % means it has negative value in some years

Business Sep 15, 2020

If I have series(variable) of FDI % of GDP with negative % means it has negative value in some years. can I push and shift to positive %? my means can I add positive value with all years to push or change the data to positive therefor to take logarithm. for example if I have series like: -0.5%, 1.3%, -1.3% and etc... so can I add +2 with all to change all to (+)? please any reference or any theory behind this?