If I have data for nominal GDP data in local currency for several countries for a given year, how can I extrapolate the nominal GDP forward?
Give that nominal GDP = quantities x prices, could I just use a growth factor that considers growth in 'quantities' and growth in 'prices'? For example, changes in real GDP per capita between the year of interest and my base year for which I have data. Similarly, changes in GDP deflator between the year of interest and my base year for which I have data.
An alternative is to simply a growth factor based on the changes in the nominal GDP between the year of interest in my base year.