Re: [R] creating dummy with loop command‏

Serdal, You still don't want explicit dummy variables. You have instead indicated that you need two factors, one for industryGroup, and one for industry nested within industryGroup. The model you suggested lnQ~lnC+lnM+lnL+lnE+eco_inno+inno+(sum)ind_3d will be easier to read and interpret as

Re: [R] creating dummy with loop command‏

Hi Dimitri, Thanks for help, i knew that way that you have suggested but in fact my case is a little bit complicated than this, therefore, i am writing a better explanation now, my model is trying to see the effect of eco-innovative industries on total output, thats why i am trying to e