Please help me with the GMM estimation ofasset pricing model
Posted: Wed Nov 20, 2013 12:35 pm
Hello everyone:
I am new to RATS. I had a hard time implementing GMM in rats.
Basically, I want to estimate an asset pricing model using GMM based on the book of Cochrane:
But i don't know how to properly specify the moment conditions.
It is about implementing a linear factor asset pricing model.
II have nine Fama-French portfolios and three risk factors.
I need to run a time-series regressions to get the coefficient estimates on three risk factors for each of the nine portfolio and the residuals should be orthogonal to the risk factors. This is the first and second moment conditions as in the screenshot of the book.(equation 12.23)
Then i need to run a cross-section regression. that is to regress coefficient estimates from the above regression (which becomes the right hand variables) on the average excess return of the portfolios. this is the third moment conditions.
The reason for using GMM is that the covariance matrix is supposed to take care the generated regressor problem and gives me robust inference.
But i really don't know how to do.
But i am able to specify the first nine time series regression and don't know how to proceed further.
I think what i need to do is to saved the estimated coefficients and the VCV of the parameter estimates and somehow tell rats to use that information in estimating the third moment conditions.
I attaches the the screenshot from cochrane's book where he specifies the moment conditions and the spreadsheet.
SMB LMH and Mkt_tvw_a are the three risk factors.
any help and suggestion is greatly appreciated.
Thank you very much.
I am new to RATS. I had a hard time implementing GMM in rats.
Basically, I want to estimate an asset pricing model using GMM based on the book of Cochrane:
But i don't know how to properly specify the moment conditions.
It is about implementing a linear factor asset pricing model.
II have nine Fama-French portfolios and three risk factors.
I need to run a time-series regressions to get the coefficient estimates on three risk factors for each of the nine portfolio and the residuals should be orthogonal to the risk factors. This is the first and second moment conditions as in the screenshot of the book.(equation 12.23)
Then i need to run a cross-section regression. that is to regress coefficient estimates from the above regression (which becomes the right hand variables) on the average excess return of the portfolios. this is the third moment conditions.
The reason for using GMM is that the covariance matrix is supposed to take care the generated regressor problem and gives me robust inference.
But i really don't know how to do.
But i am able to specify the first nine time series regression and don't know how to proceed further.
I think what i need to do is to saved the estimated coefficients and the VCV of the parameter estimates and somehow tell rats to use that information in estimating the third moment conditions.
I attaches the the screenshot from cochrane's book where he specifies the moment conditions and the spreadsheet.
SMB LMH and Mkt_tvw_a are the three risk factors.
any help and suggestion is greatly appreciated.
Thank you very much.