title_body: What does Fair Trade guarantee?
upvoted_answer: If you mean the coffee bean farmer by 'end-producer',
  Fair Trade guarantees a relative increase of the contract that the farmer can negotiate. 
  
  Say, for example a farmer gets USD 20,- for his entire crop usually, then
  
  He might get USD 140,- for the same amount of beans when selling to a Fair Trade contracter. 
  Also see: How much do the farmers get about prices in Ethiopia.