What I implemented is to use weights based on emissions in ABFLOW011 sector for both 1A1B and 1A1C. The choice was between this solution or a simple arithmetic average.
Arguably a cleaner solution would be to use UNFCCC data to calculate weights that would allow allocation of emissions from ABFLOW011 to 1A1B and 1A1C; but that would only affect economy-wide price estimates, not sector-level ones, since it wouldn't affect the share of fuel-specific emissions in each sector.
What I implemented is to use weights based on emissions in ABFLOW011 sector for both 1A1B and 1A1C. The choice was between this solution or a simple arithmetic average.
Arguably a cleaner solution would be to use UNFCCC data to calculate weights that would allow allocation of emissions from ABFLOW011 to 1A1B and 1A1C; but that would only affect economy-wide price estimates, not sector-level ones, since it wouldn't affect the share of fuel-specific emissions in each sector.