Catherine Hood Consulting

Frequently Asked Questions

Definitions and Concepts

1. What is a time series?
2. What is seasonal adjustment?
3. What kind of data do we need for seasonal adjustment?
4. Why seasonally adjust data?
5. How much data do I need to get a reasonable adjustment?
6. What are the components of a time series decomposition?
7. What effects are removed during seasonal adjustment?
8. What is an ARIMA model?
9. What is a regARIMA model?
10. How do I generate a seasonally adjusted series?
11. What are seasonal filters?
12. What are trend filters?
13. Why do the seasonal factors change when new data is added?
14. How do I choose between additive and a multiplicative models?
15. What is an indirect (or a direct) adjustment? Why would I need one?

Information on X-12-ARIMA and X-13ARIMA-SEATS

1. What is X-12-ARIMA and X-13ARIMA-SEATS?
2. How do I get a copy of X-13ARIMA-SEATS?
3. How do I run X-12-ARIMA and/or X-13ARIMA-SEATS?
4. How do I find what I need from the output file?
5. How do I save output into Excel?
6. How does X-12/X-13 estimate the trend and seasonal components?
7. How does X-12/X-13 estimate the trading day and moving holiday components?
8. What seasonal filters are available in X-12/X-13?
9. What trend filters are available in X-12/X-13?
10. How does X-12/X-13 handle extreme values or outliers?
11. What if I have a holiday not included in X-12/X-13?
12. How do I process a large number of series?
13. How do I get X-12/X-13 to calculate an adjustment for the total of my series?
14. How do I get updates and/or more information on X-13ARIMA-SEATS?
15. Is there training available?
16. How do I get started?
17. Can I run X-12/X-13 from Excel?
18. What is new in X-13ARIMA-SEATS?
19. Why should I switch to X-13ARIMA-SEATS?
20. How do I know if ARIMA-model-based adjustments are right for my series?

Information on TRAMO/SEATS

1. What is TRAMO/SEATS?
2. How do I get a copy of TRAMO/SEATS?
3. How do I run TRAMO/SEATS?
4. Can I run TRAMO/SEATS from Excel?
5. How does TRAMO/SEATS estimate the trend and seasonal components?
6. How does TRAMO/SEATS estimate the trading day and moving holiday components?
7. How does TRAMO/SEATS handle outliers?
8. How do I get more information? Is there training available?
9. How do I get started?

Diagnostics-Related Questions

1. What are the features of a quality seasonal adjustment?
2. What diagnostics are available in X-13 to help us judge the quality of the adjustment?
3. What do I do if the diagnostics fail?
4. How do I "fix" failing M diagnostics?
5. How much data do I need to get diagnostics information from X-13?

Trouble-Shooting

1. What do I do if I can't get X-13 to run?
2. What do I do if I can't get X-13 installed?
3. How can I get X-13 to run for my short series?
4. How can I get X-13 to run for my weekly series?
5. What do I do if I click on a spec file and I get an error message?

Back to the Top