Hi all,

Can you please tell me what is the problem here.

My regression eq is  y = B0 + B1X1 +B2X2 +e
And i am interested in coefficient B1

I am doing regression with two cases:

1) reg<-lm(y ~ X1 + X2, sam) where sam is the data

2) reg<-lm(y ~ X1 + X2, sam, na.action= na.exclude) . I have missing values
in X1


but the values of coefficient is not consistent in two cases.

Actually B1 in case one sould be smaller than B1 in case 2. But sometimes it
comes greater.

I can't figure it out. Is there some problem with *na.action ? *My sample
size is 100


*Regards,*
*Vaibhav*

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