Re: why do I get negative Rsquared in SURE?
Posted: Mon Dec 15, 2008 5:12 am
Your results indicate extreme serial correlation. It appears that your prices are nonstationary, which is not unusual.
And could you please explain me why you said it was extreme serial correlation from those results? Even the Durbin-watson stats results above were all around 1.7, or because I include AR in the specification. I mean from which result you can conclude that. Please explain me because I want to understand how to interpret the results of SUR (with AR).Your results indicate extreme serial correlation. It appears that your prices are nonstationary, which is not unusual.
The use of the AR term makes c(2) the estimate of the first-order serial correlation coefficient.And could you please explain me why you said it was extreme serial correlation from those results? Even the Durbin-watson stats results above were all around 1.7, or because I include AR in the specification. I mean from which result you can conclude that. Please explain me because I want to understand how to interpret the results of SUR (with AR).Your results indicate extreme serial correlation. It appears that your prices are nonstationary, which is not unusual.
Many thanks!
The interpretation is that the error terms in the equations have the formI am sorry that I read many different textbooks on econometrics and also explanations form the internet, but not only a certain book. Anyway for sure, the specification I used with AR term as above is right or not, and how to interpret the results of c(2) in the results.
I have a question that as you mentioned above, is c(2) the "p" in the fomula "x_t = px_t−1 + e_t" I met in many textbooks?The interpretation is that the error terms in the equations have the formI am sorry that I read many different textbooks on econometrics and also explanations form the internet, but not only a certain book. Anyway for sure, the specification I used with AR term as above is right or not, and how to interpret the results of c(2) in the results.
u_t = c(2)*u_(t-1) + epsilon_t
Since you have c(2) around 1, the effect of a shock is essentially permanent. The is a standard result for an asset price.
Unfortunately, this may suggest that the coefficients without the serial correlation correction are wrong.Thannk you for your prompt reply! As you know the results indicate serial correlation, do you have any suggestions for me to solve this problem? It seems that using AR term is not a good solution, since the coeffecients in the analysis are to much different with results of an estimation withour AR term.
That's right!I have a question that as you mentioned above, is c(2) the "p" in the fomula "x_t = px_t−1 + e_t" I met in many textbooks?The interpretation is that the error terms in the equations have the formI am sorry that I read many different textbooks on econometrics and also explanations form the internet, but not only a certain book. Anyway for sure, the specification I used with AR term as above is right or not, and how to interpret the results of c(2) in the results.
u_t = c(2)*u_(t-1) + epsilon_t
Since you have c(2) around 1, the effect of a shock is essentially permanent. The is a standard result for an asset price.
Thank you. Thus you mean the coefficients got from the estimation with AR term are right, dont you? And results of durbin-watson stat which are around 1.7 in that analysis can indicate no serial correlation, can't they? Can I use that analysis for my research? I am really worried about this analysis due to presence of serial correlation, that is why I put you so many quetions about that. And please apologize me for poor knowledge of this area.Unfortunately, this may suggest that the coefficients without the serial correlation correction are wrong.Thannk you for your prompt reply! As you know the results indicate serial correlation, do you have any suggestions for me to solve this problem? It seems that using AR term is not a good solution, since the coeffecients in the analysis are to much different with results of an estimation withour AR term.
You've hit on something that is easy to get confused about in EViews. The Durbin-Watson statistics from the regressions including the AR(1) term are a check for further serial correlation. So unless you were getting satisfactory Durbin-Watson's before including the AR term, which is unlikely, you're sort of stuck with the problem.Thank you. Thus you mean the coefficients got from the estimation with AR term are right, dont you? And results of durbin-watson stat which are around 1.7 in that analysis can indicate no serial correlation, can't they? Can I use that analysis for my research? I am really worried about this analysis due to presence of serial correlation, that is why I put you so many quetions about that. And please apologize me for poor knowledge of this area.Unfortunately, this may suggest that the coefficients without the serial correlation correction are wrong.Thannk you for your prompt reply! As you know the results indicate serial correlation, do you have any suggestions for me to solve this problem? It seems that using AR term is not a good solution, since the coeffecients in the analysis are to much different with results of an estimation withour AR term.