Hi all,
I used cross-sectional data and poisson regression. I did stepwise regression but found the coefficients of the linear term and the quadratic term become insignificant after dropping the interaction term. How comes it happen? And how do I solve this problem?
Thanks,
David
Reuslts:



I used cross-sectional data and poisson regression. I did stepwise regression but found the coefficients of the linear term and the quadratic term become insignificant after dropping the interaction term. How comes it happen? And how do I solve this problem?
Thanks,
David
Code:
poisson income iv1t iv2 cv1 cv2 cv3 cv4 i.indcode, vce(robust) poisson income iv1t iv2 c.iv2#c.iv2 cv1 cv2 cv3 cv4 i.indcode, vce(robust) poisson income c.iv1t##c.iv2 c.iv1t#c.iv1t c.iv2#c.iv2 cv1 cv2 cv3 cv4 i.indcode, vce(robust)
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