Adjusting weights with pooled 5-year ACS files?

I have pooled together two different 5-Year ACS files. Now, I’m wondering about what to do with the weights (hhwt and perwt). I understand that in the 5-Year files they are already adjusted. Now, that I’ve pooled two 5-year files, should I divide the weighting variables by 2? Thanks a lot in advance!

Yes, this is the method Census uses to modify the weights in the multi-year ACS files (see page 28 of the technical documentation). Modifying the weights is technically only necessary if you’re looking to generate population-level totals or incorporate those into your analysis (e.g. the total number of people who are unemployed). It is not necessary to alter the weights when working with population means (e.g. average income).