there may be ...

Dear Rajendra Poudel 

Thank you very much for your response. The material you attached helps a lot. 

But what I what to ask is that in a study where there is adopter and no-adopter of a technology, if some one want to study the impact of  adoption for adopter while willingness to pay for non adopter of the same technology. is there any way or possibility at the same time.

thanks indeed, i hope so

Yes, you can. Start by selecting variables which can explain both adoption and WTP before data collection or select these variables if data are collected.

thank you !