Choosing lag length for Panel Unit Root Test

[dibeltran]

In the Panel Unit Root Test for IPS, there is an option to choose lag length automatically called t-statistic. Is this option the same as the step-down procedure where one:
1. starts with a large number of lags.
2. Test significance of largest lag.
3. If significant, stop process and chosse this truncation.
4. If not significant reduce lags by one and repeat 2 and 3.
5. Continue process until you reach some lag that is significant.
Thank you.