General Instructions for Opening an Extract

The IPUMS-PMA extract system provides formatted data in the format specified by the user (Stata, SAS, SPSS, or CSV [comma delimited]), as well as an ASCII data file that can be read into another format using command files.

Step 1: Download your data

On the My Extract Requests page, you will see your extract requests along with the creation date, optional description, and links to the following: Formatted data in your chosen format, ASCII format data, command files for R, SPSS, SAS, and Stata, and a Basic Codebook.

Download the formatted data file. Right click on the link under "Formatted Data" and select "Save Link As".

Step 2: Decompress the file

Note that R does not require data files to be decompressed.

The downloaded data file should have the suffix ".gz", such as "pma_0001.dta.gz" (for a file in Stata format). This file needs to be decompressed. Mac OS X will decompress the file when you double-click it. Most Windows users will have some type of application that unizips compressed files, but a significant number may not. If your Windows-based computer does not know how to decompress the file, you need to download decompression software. A free option is 7-Zip; other programs are also available.

To download the full version of 7-Zip (recommended):

Go to http://www.7-zip.org/download.html.

Click on the first link (32-bit x86) to download the 7-zip installer onto your PC. (You can choose 64-bit, if that matches your version of Windows, but 32-bit should always work. Always choose an ".exe" file.)

Click on the downloaded file to intall 7-zip (say "yes" or "ok" when prompted).

7-zip should now appear in your list of programs from the Start menu.

Start 7-zip and navigate to the IPUMS-PMA file you want to decompress. (Note: Navigating through your folders within 7-zip can be challenging. It may be easiest if you move your IPUMS-PMA file into "Documents" before you start 7-zip. "Documents" is always listed as the default location in the 7-zip program.)

Select the IPUMS-PMA file within 7-zip and hit the "Extract" button to decompress the file.

To download the portable version of 7-Zip (for users without admin priviledges on their PC):

Download the program: Portable version 7-Zip

Move the installer file to where you want to install the program. Install by double-clicking on it. The 7-zip program (.exe) will by in a 7-zip folder in that location.

Open the program. Navigate to the file you want to decompress and hit "Extract."

When decompression is complete, you should see a file without the suffix ".gz". Note the path to the location of the file on your computer. If you are unsure about the path to the file, right-click on the file and choose "Properties" (or, on Mac, "Get Info"). The path is indicated in the "Location:" section of the Properties or Get Info window.

Step 3: Click on the file name to open your statistical package and begin to analyze the variables included in your data extract.