Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Showing results for

- JMP User Community
- :
- Discussions
- :
- reading results of Augmented Dickey-Fuller Unit Ro...

- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Get Direct Link
- Email to a Friend
- Report Inappropriate Content

May 12, 2010 10:23 PM
(4355 views)

With ARIMA procedure, I can carry out Augmented Dickey-Fuller Unit Root Test. However, I do not understand 'rho' in test output and I can not find any related information in sas documents or statistical books/literatures.

I assume that 'rho' is coefficient on 1st lag and has range [-1,1]; and I assume that unit root test is to find out 'rho' equal to 1 or not. For instance, Y(t) = ...+'rho'Y(t-1)+... However, in my test results, I get 'rho' value as big as 50.

Would you please do me a favor and explain what 'rho' means here?

Many thanks.

My e-mail is as follow:

yunfei.zhao@email.wsu.edu

Yunfei Zhao

1 ACCEPTED SOLUTION

Accepted Solutions

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Get Direct Link
- Email to a Friend
- Report Inappropriate Content

May 16, 2010 9:20 AM
(4108 views)

Solution

I asked a similar question and this is the response from JMP Technical Support:

Dear Mark,

Thank you for your question regarding ADF tests in JMP.

The values printed for the Zero Mean, Single Mean and Trend ADF in JMP are the Tau statistics associated with the Dickey-Fuller test. Because Dickey and Fuller produced look-up tables for the critical values associated with the distribution of the Tau statistic, and because the associated p-values would only be approximations, the developer decided not to print approximate p-values for these statistics. Tabled values may be found in the following references:

Dickey, D. A. and Fuller, W. A. (1979), "Distribution of the Estimation for Autoregressive Time Series with a Unit Root," Journal of the American Statistical Association, 74, 427-431.

Dickey, D. A., Hasza, D. P., and Fuller, W. A. (1984), "Testing for Unit Roots in Seasonal Time Series," Journal of the American Statistical Association, 79, 355-367.

Another excellent reference for the Dickey-Fuller tests is:

Hamilton, J. D. (1994), Time Series Analysis, Princeton: Princeton University Press.

You may want to refer to the tables noted in the above references to determine the significance of the test statistics printed by JMP.

Dear Mark,

Thank you for your question regarding ADF tests in JMP.

The values printed for the Zero Mean, Single Mean and Trend ADF in JMP are the Tau statistics associated with the Dickey-Fuller test. Because Dickey and Fuller produced look-up tables for the critical values associated with the distribution of the Tau statistic, and because the associated p-values would only be approximations, the developer decided not to print approximate p-values for these statistics. Tabled values may be found in the following references:

Dickey, D. A. and Fuller, W. A. (1979), "Distribution of the Estimation for Autoregressive Time Series with a Unit Root," Journal of the American Statistical Association, 74, 427-431.

Dickey, D. A., Hasza, D. P., and Fuller, W. A. (1984), "Testing for Unit Roots in Seasonal Time Series," Journal of the American Statistical Association, 79, 355-367.

Another excellent reference for the Dickey-Fuller tests is:

Hamilton, J. D. (1994), Time Series Analysis, Princeton: Princeton University Press.

You may want to refer to the tables noted in the above references to determine the significance of the test statistics printed by JMP.

2 REPLIES

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Get Direct Link
- Email to a Friend
- Report Inappropriate Content

May 16, 2010 9:20 AM
(4109 views)

Dear Mark,

Thank you for your question regarding ADF tests in JMP.

The values printed for the Zero Mean, Single Mean and Trend ADF in JMP are the Tau statistics associated with the Dickey-Fuller test. Because Dickey and Fuller produced look-up tables for the critical values associated with the distribution of the Tau statistic, and because the associated p-values would only be approximations, the developer decided not to print approximate p-values for these statistics. Tabled values may be found in the following references:

Dickey, D. A. and Fuller, W. A. (1979), "Distribution of the Estimation for Autoregressive Time Series with a Unit Root," Journal of the American Statistical Association, 74, 427-431.

Dickey, D. A., Hasza, D. P., and Fuller, W. A. (1984), "Testing for Unit Roots in Seasonal Time Series," Journal of the American Statistical Association, 79, 355-367.

Another excellent reference for the Dickey-Fuller tests is:

Hamilton, J. D. (1994), Time Series Analysis, Princeton: Princeton University Press.

You may want to refer to the tables noted in the above references to determine the significance of the test statistics printed by JMP.

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Get Direct Link
- Email to a Friend
- Report Inappropriate Content

Dec 29, 2014 5:11 AM
(2206 views)

You have to decide what model you test for. JMP gives you the statistics for all three models. The critical values are not provided by JMP (in version 10), but can be found in a simple Google search (see below). Check out this example also: ADF Augmented Dickey-Fuller Unit Root Test - YouTube:

Pasted from <http://akson.sgh.waw.pl/~mrubas/EP/TabliceStatystyczneDF.doc> :

Critical Values for the Dickey-Fuller

Unit Root t-Test Statistics

Probability to the Right of Critical Value

Model Statistic N 1% 2.5% 5% 10% 90% 95% 97.5% 99%

Model I (no constant, no trend)

ADFtr 25 -2.66 -2.26 -1.95 -1.60 0.92 1.33 1.70 2.16

50 -2.62 -2.25 -1.95 -1.61 0.91 1.31 1.66 2.08

100 -2.60 -2.24 -1.95 -1.61 0.90 1.29 1.64 2.03

250 -2.58 -2.23 -1.95 -1.61 0.89 1.29 1.63 2.01

500 -2.58 -2.23 -1.95 -1.61 0.89 1.28 1.62 2.00

>500 -2.58 -2.23 -1.95 -1.61 0.89 1.28 1.62 2.00

Model II (constant, no trend)

ADFtr 25 -3.75 -3.33 -3.00 -2.62 -0.37 0.00 0.34 0.72

50 -3.58 -3.22 -2.93 -2.60 -0.40 -0.03 0.29 0.66

100 -3.51 -3.17 -2.89 -2.58 -0.42 -0.05 0.26 0.63

250 -3.46 -3.14 -2.88 -2.57 -0.42 -0.06 0.24 0.62

500 -3.44 -3.13 -2.87 -2.57 -0.43 -0.07 0.24 0.61

>500 -3.43 -3.12 -2.86 -2.57 -0.44 -0.07 0.23 0.60

Model III (constant, trend)

ADFtr 25 -4.38 -3.95 -3.60 -3.24 -1.14 -0.80 -0.50 -0.15

50 -4.15 -3.80 -3.50 -3.18 -1.19 -0.87 -0.58 -0.24

100 -4.04 -3.73 -3.45 -3.15 -1.22 -0.90 -0.62 -0.28

250 -3.99 -3.69 -3.43 -3.13 -1.23 -0.92 -0.64 -0.31

500 -3.98 -3.68 -3.42 -3.13 -1.24 -0.93 -0.65 -0.32

>500 -3.96 -3.66 -3.41 -3.12 -1.25 -0.94 -0.66 -0.33

This widget could not be displayed.