Hi everyone,
This is my first post in this forum after several years of lurking.
My question is: how come I cannot run PDOLS regressions with more than 6 independent variables with xtpedroni? Instead I get the message "not positive definitive" and some diff/demeaned variables are created. Is there a theoretical reason behind it?
I checked on the online Stata literature and forum posts but I could not find any explicit explanation of it. I tried this with other datasets and I get the same result, so I am pretty sure it is not just due to my dataset.
I am using Stata/SE 13.1.
Thank you in advance.
This is my first post in this forum after several years of lurking.
My question is: how come I cannot run PDOLS regressions with more than 6 independent variables with xtpedroni? Instead I get the message "not positive definitive" and some diff/demeaned variables are created. Is there a theoretical reason behind it?
I checked on the online Stata literature and forum posts but I could not find any explicit explanation of it. I tried this with other datasets and I get the same result, so I am pretty sure it is not just due to my dataset.
I am using Stata/SE 13.1.
Thank you in advance.