Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

Re: st: panel unit root test t=4 / pooled estimation


From   Daniel Becker <[email protected]>
To   [email protected]
Subject   Re: st: panel unit root test t=4 / pooled estimation
Date   Mon, 11 Aug 2008 18:23:52 +0200

... answering my own question: 4 observations in the time dimension are not enough ...

I guess it is so obvious that nobody felt the need to answer ... Sorry for the noise.

D


Am 08.08.2008 um 19:31 schrieb Daniel Becker:


Dear statalister,

maybe the question is a bit silly, but maybe someone has the time...

I have a panel with 74 cross-sectional observations and 4 year (1985,1990,1995,2000). I decided to ignore the time dimension and did a regression that includes dummies for the last three out of the four years.

However, "regress depvar year" and a scatter plot suggest that my dependent variable has a trend. So I thought that I should have a look at stationarity. But is this necessary if I am not making use of the time dimension anyway?

Secondly, while exploring several tests for unit roots, that most of time seem to reject the existence of a unit root, I started to think whether those test really are meaningful in my case. In the end, there are only 4 years in the panel. (And, in addition, I do not really know what an approbiate lag-length might be.)

So my questions are:

Is stationarity important if the estimation is done in a pooled panel?

Are panel unit-root tests valid if the time-dimension is very short?

Thanks for your help,

Daniel




*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index