Why are variable names different?

I just downloaded some 2012 5-year ACS data from ipums, and I noticed that the variable names are different in the dataset than in the Data Dictionary (http://www.census.gov/acs/www/Downloa…). For example - the variable name in my data re: Units in structure is “unitsstr”, but the variable name in the data dictionary is “BLD”. Does anyone know why this is the case?

IPUMS-USA recodes most of the variables in the Public Use Microdata file distributed by the Census Bureau in order to harmonize the data for over time analysis. Thus, new variable names are assigned to emphasize the fact that the codes are different. When you create an IPUMS-USA extract a Codebook is created as well giving the variable names, definitions, and value labels associated with the data you extracted. You can find the uniquely created codebook on the same row as your extract in your Download and Revise Extracts area.

I hope this helps.

Thank you for this information. Is it possible to access a data dictionary/codebook for all of the variables? I’m trying to identify variables that may be of interest, and I would find that a bit easier to do if I could access the entire data dictionary to identify relevant variables rather than trial and error through adding variables to my cart.

If you’re looking for data within a specific topic of interest, I would be more than happy to help guide you to some relevant variables. IPUMS does not provide a master data dictionary for all available variables. However, you can edit how variables are displayed in the extract system to show all of the available variables. To do this in IPUMS CPS, you can click on Select Data and then click on the Display Options button (see screenshot). You can then select to Show all groups together under variable groups. You might also select Display under Variables that are not available for the selected samples in order to display all variables regardless of whether they are available in the sample months that you selected.

The number of variables in IPUMS CPS is immense. If displaying all variables is not convenient, you might try another approach by browsing the CPS supplement guides which contain information on the types of questions that are asked in the various supplements as well as links to the survey codebooks.You can also search for variables using the search bar.