Three things are at work here:

1. The big difference is that IHDS 1 is monthly per capita and IHDS 2 is annual. The IHDS 2 variable will be changed back to monthly during the next data update.

2. Price changes: There is a variable, DEFLATOR, in the public IHDS 2 file; mean= .5453441 .

3. Economic growth.

For example, take the mean above for IHDS 1: 955.09 multiply by 12 months and divide by the average IHDS 2 deflator, .5453441=21,016. The difference between 21,016 for IHDS-I and 27,155 for IHDS 2 is a measure of economic growth.

You will need to do this separately for each household. Please note, there is not a hh “inflator” for the IHDS 1 file. So, you can deflate the IHDS 2 households by dividing by 12 months and multiplying by DEFLATOR. This will give IHDS 2 totals in IHDS 1 prices.