Now I have the following 2SLS model: I have 25 year dummy variables and 48 industry dummies, which are shown yr1-yr24 and ind1-ind47.
proc syslin data=robtest1 2sls first;
instruments bcg_mtrnoint logpps size logavg mtb pci yr1-yr24 ind1-ind47;
model wage = logpps lev size logavg mtb pci yr1-yr24 ind1-ind47;
When I run it, the log shows WARNING: The model is not of full rank. Least Squares solutions for parameters are not unique. Certain statistics will be misleading. A reported degree of freedom of 0 or B means the estimate is biased.
And my 1st ad 2nd stage results show "intercept" with DF "0". What does the warning mean and how do I correct my model? Thanks a lot!!!
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