I am using the ACS (IPUMS-USA) for several years and would like to specify date of birth as precisely as possible. For the variable age the description is the following: “AGE reports the person’s age in years as of the last birthday.” What exactly does “last birthday” mean, is it age as of 1st of April in the year of the survey?
If the cutoff-date is indeed 1st of April, then an individual whose age is reported as 10 years in the ACS 2010 was born in 1990 if his quarter of birth is the 1st quarter. In case the quarter of birth is the 2nd, 3rd or 4th quarter, that individual was born in 1989.
Can anybody confirm or reject this? Thanks a lot!