I am trying to estimate the total population using the ASEC IPUMS by summing WTSUPP for every year. This doesn’t add up to a number that looks like total population. Instead I get, for example, 193.7 million for the total population in 2013. Isn’t WTSUPP supposed to be the population weight that adds up to approximately the Census Population Estimates series?
I downloaded your extract #5, but I am unable to replicate your issue. When I sum the WTSUPP values for the 2013 March ASEC, I get a total of just over 311 million. I confirmed that the sums of WTSUPP for the years 1976-2015 also look correct. My recommendation is to confirm you have not dropped any observations from the ASEC sample before summing WTSUPP. If you have not, I recommend downloading your extract again, as it is large and may not have completely downloaded.
Hope this helps.