I am currently using 1980, 1990, 2000 Census, and 2006-2008 3 year ACS to build up the database. But it seems that Census and ACS database are quite different in terms of sample representativeness even after I adjust with “perwt” variable.
For example, if I simply sum up the population and employment within year after adjusting with “perwt” variable, I am getting the following number:
year 1980: employment 4,949,357; total population 1.13e+07
year 1990: employment 5,902,657; total population 1.25e+07
year 2000: employment 6,546,089; total population 1.41e+07
year 2008: employment 4,293,972; total population 8,965,060
Employment is based on “empstat” variable. I expected larger number of employment and total population for the year 2008, but number gets smaller. That is, it seems that ACS and Census are not compatible even after I adjust with “perwt” variable.
Do I need to further adjust the ACS database to make it compatible with Census database? Your help would be greatly appreciated!