question on ACS variable meaning

Hi everyone,
 
I have a question on the variables relating to the "presence and types of internet subscriptions in household" group of the ACS 2017 5 year data that was recently released.
 
From what I understand, the data on internet subscriptions is reported in terms of household units, not persons. The variable B28002_001E has a description of "total estimate", but I don't know what this is referring to. Is it the total estimate of households with an internet subscription? Or just some form of access to internet? I see that there is another variable B28002_002E which represents the estimated number of households with an internet subscription and there is B28002_013E which represents the number of households without internet access. Summing these two variables gives a value that is very close to that of B28002_001E, which makes me think that this variable may be the sample size of households surveyed.
 
What I would like to do is to calculate the proportion of households with and without access to internet by county. I see there is another variable B25001_001E which represents the estimated total number of housing units, so am not sure whether I should use this value to calculate the proportion of households with and without internet, or if I should use the B28002_001E variable to do so.
 
Any suggestions or guidance would be greatly appreciated, thanks!
 
- Chris
  • Hi Chris,

    B28002_001 would be the total number of households (with or without an internet subscription). This is useful as a denominator for creating percentages with the other indicators. 002 is households with any kind of internet subscription. The sum of 002, 012 (internet without a subscription), and 013 (no internet) should equal 001.

    Most ACS tables will begin with an indicator of the total universe (all households, people, etc.) described in the table, so many 001 indicators from different tables will be the same.

  • In reply to Bernie:

    Hi Bernie,

    Thanks so much for the response, I appreciate it.

    So for the 001 value, I've noticed it is less then the value for B25001_001E which I believe is the estimate of total households in a geographic area. Is there a reason that the values for B28002_001 and B25001_001E would differ?

    Also, if I'd like to calculate the total number of households without internet access, should I just use the B28002_001 number? Or should I calculate it by doing B28002_001 / B28002_001 * B25001_001E ?

    regards,

    - Chris
  • In reply to clhenrick:

    Hi Chris,

    The universe for table B25001 is housing units, whereas the universe for table B28002 is housing units, which would include vacant housing units, so they're not equal.

    So when you do your calculations, it would be a good idea to stay within a table. For your numerator of households without internet access, you'd use B28002_013. So if you want the percent of households without internet access, you would calculate it by doing B28002_013 / B28002_001.

    If you haven't seen it, the ACS table shells document might be useful to download and look at. You can access it here: www.census.gov/.../table-shells.html (click on the link under "Table Shells for All Detailed Tables").
  • In reply to Bernie:

    Hi Bernie,

    That makes a lot of sense, I appreciate the guidance. I had not come across the table shells yet either, it's a helpful resource.

    - Chris