I use the one year ACS to calculate poverty of Los Angeles County every year. The results for total population below the 100 % poverty are usually close to the published American FactFinder data. Last year (2014 ACS) I got numbers that were lower and was told that a new IPUMS file had been uploaded with some adjustments to the poverty numbers. After that the numbers came out much closer to the American FactFinder numbers.
For 2015 I again got numbers that were lower than the American Factfinder.
Los Angeles County
American Factfinder 1,668,129 number in poverty 16.6%
IPUMS 1,621,789 number in poverty 16.2%
I tried California and
American FactFinder 5,891,678 number in poverty 15.3%
IPUMS 5,647,483 number in poverty 14.7%
The total number of people seems accurate and the universe for poverty seems accurate. For Los Angeles the the poverty rate is in the margin of error. But for both LA and CA the number below poverty was not in the margin of error.
I use the coding:
If (pov > 0 and pov < 100) pov100 = 1.
I have read in the IPUMS documentation that IPUMS poverty numbers are usually higher because of some change in subfamily poverty numbers.
Do you have any thoughts on these results?