Hi,

I am using tsls function from sem package to estimate a model which includes large number of data. Among its predictors, it has a nominal data which has about 10 possible values. So I expand this parameter into 9-binary-value predictors with the coefficient of base value equals 0. I also have another continuous predictor. 

The problem is that, whenever I run the tsls, I will get 'System is computationally singular' error all the time. I'm wondering if there is anyway that I can overcome this problem? Please kindly suggest. Thank you so much in advance.

- adschai

	[[alternative HTML version deleted]]

