Panda algorithm works against content farming in which there is no availability of duplicate content.Google do not give the priority to the copied content.So that there should be availability of fresh and new contents in the website.

panda update was supposed to improve quality.Google identified and penalized the rankings of sites that copy or "scrape" the content of other sites; sites that have low-quality content; sites that have a high ratio of ads to content; and sites that lack brand trust.