Catherine Hood Consulting

Trouble-Shooting FAQ

1. What do I do if I can't get X-12-ARIMA to run?
2. How can I get X-12-ARIMA to run for my short series?
3. Will X-12-ARIMA run in Windows Vista/Windows 7?
4. What do I do if I click on a spec file and I get an error about Microsoft PKCS #7 Certificates files?

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1. What do I do if I can't get X-12-ARIMA to run?

If you are not using the Windows interface to X-12, you should download this program. X-12-ARIMA is a DOS program, and it will not run if you simply double-click on an X-12 input file.

If you are using the Windows interface to X-12, you may want to download the newest version of the program from December 2009.

If you are running the older version of the interface, the first step is to check the directory structure of your computer compared to the .ini file that comes with the program.

If you are running the December 2009 version of the interface and it doesn't load, it could be a sign that you've changed the directory where the program is. If you want to move the program, you should probably reinstall the program .

There is help available on X-12-ARIMA and the interface from the US Census Bureau by writing to the address x12a at census.gov.

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2. How can I get X-12-ARIMA to run for my short series?

The minimum length to seasonally adjust a time series in X-12-ARIMA is four years. However, there is something we can do for short series.

Seasonal adjustment can be difficult under the following conditions:

• The trend is not approximated by a straight line.
• Trading day and moving holiday regressors are present.
• Outliers (level shifts or point outliers) are present.

Fortunately, if we have a short series that is fairly well-approximated by a straight line, and if we don’t need to estimate trading day, moving holidays, or outliers, then we can do a simple seasonal adjustment in Excel. The good news is that for short series, we probably can estimate the trend fairly well with a straight line. With only a few data points for a particular month or quarter, we don’t have enough data to estimate trading day or moving holiday effects anyway, so we won’t try to estimate them.

I've outlined the steps to compute a seasonal adjustment, with examples, in the paper (in PDF) "Seasonal Adjustment for Short Time Series in Excel."

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3. Will X-12-ARIMA run in Windows Vista/Windows 7?

X-12-ARIMA does run Windows Vista, Windows 7, and earlier versions of Windows. Your can run X-12 using the Windows interface, or run X-12 from the command prompt. You can download Win X-12 (the Windows interface to X-12) for free from the Census Bureau site at

http://www.census.gov/srd/www/x12a/winx12home.html.

I have been using the interfaces in Windows Vista for years without any problems.

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4. What do I do if I click on a spec file and I get an error about Microsoft PKCS #7 Certificates files?

Below are some tips for editing spec files. Thanks to Kathleen M. McDonald-Johnson for writing the tips for older versions of Windows.

Some people have had trouble with spec files (extension .spc) because the file extension is already associated with Microsoft files of type PKCS #7 Certificates.

One solution is to open the text editor (NotePad, PFE, etc.) first and then open the spec file from the editor. However, many of us find it more convenient to be able to double click on the file name in Windows Explorer.

In versions of Windows BEFORE Vista,
the following steps are a guide to setting up the file type:

1. Open the Windows Explorer (if you don't have a shortcut set up, you can right click on the start button and then choose Explore or you can open Programs in the Start Menu and choose the Explorer program).
2. In the Windows Explorer, click on View in the top line menu - then Options - then click on the File Types tab in the window.
3. In list of file types, scroll down to "PKCS #7 Certificates" (you can type "p" to jump to the "p" file section).
4. Highlight the PKCS #7 Certificates file type, and click on the Edit box. Verify that this file type is associated with the .spc extension. If it is not, then check the error message that you get when you double-click on spec files. You need to find the file type associated with the .spc extension to complete these steps.
5. Change the File Description if you want. For instance, use "Spec File / PKCS #7 Certificates," or leave it as it is if that will help you remember. This file type is what Explorer sorts by in the normal folder contents view when you click on "Type."
6. Click on the New... button.
7. Type the Action description in the Action box. (Some like to use Action names like "NotePad" or "WordPad." Others like to use Actions like "Open," "Edit," or "View.")
8. Choose the Application that you want to use to edit the spec files. You can use any text-editing program. Many users like to use Notepad. You can browse to find the application, if it doesn't come up automatically. NotePad is usually in the Windows directory, c:\Windows\NotePad.exe.
9. Click on Okay.
10. Highlight your new action and click on the Set Default button. Then click okay. (You can also change the icon if you have one that is more useful.)
11. It's a good idea to check that Windows has accepted the changes. To check, click Edit again. If everything is okay, click on okay. If none of the actions are bold, then highlight the one you want, and click on Set Default again, then click okay.

You can add several Actions if you think you will use different programs in different settings - you might like one program better for editing, but another program for times when you just want to view the file quickly. To access the different actions, right click on the file instead of double clicking. Make your favorite program the default so it will open when you double-click on the spec file.

In Windows Vista,
the following steps are a guide to setting up the file type:

1. Click on the "Start button" at the bottom left of the screen. Choose a folder on the right of the pop-up window, such as Documents, to open Windows Explorer.
2. Use Windows Explorer to open the folder/directory that contains your .spc files.
3. Right-click one of the .spc files, and then click "Open With". If "Open With" does not appear as a choice, click "Open".
4. From this window, select the text editing program you would like to use to open this file automatically. Many users like to use Notepad.
5. Select the "Always use the selected program to open this kind of file" check box, and then click OK.
6. It's a good idea to check that Windows has accepted the changes. To check, double-click on a file to make sure it opens in your text editor.

You can use these steps for all the different kinds of X-12 input, output, and save files. If the file type doesn't have another program associated with it yet, you can click on New Type instead of Edit.

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