What does "N.A." mean in the ACS IPUMS occupational classifications?


I’m working with the ACS 2009-2011 IPUMS data. In the occupational 2002 recode (occp02), two-thirds of respondents are classified as “N.A.” It’s about one-third in the 2010 recode (occp10). The data dictionary defines N.A. as “Code classification is Not Applicable, record in universe.” These people are in the universe, because missing values are used for those who are “less than 16 years old/NILF who last worked more than 5 years ago or never worked”.

What does “Code classification is Not Applicable” mean? Am I being dense? Does it mean that the coders were unable to classify the worker? It would be surprising for that to happen to so many respondents.



I’m sorry, but I’m not sure that I understand your question. We don’t have any variables named ‘occp02’ or ‘occp10’ in the IPUMS version of the ACS files.

Hi Brandon,

Ok. I’m sure this is my fault, but I’m very confused and your help would be appreciated.

I downloaded the 2009-2011 American Community Survey 3-Year Public Use Microdata Sample from here:

I’ve been using the data dictionary from the Census Bureau’s ACS page. Specifically, the file I’m looking at is here:


I ran into a problem, and looked around for some “Contact Us” page and came across a link to this website (I did not originally download the data from this website).

Clearly, I’m confused. What am I missing?