What are your ideas on the economic systems of communism and socialism? Would either work and if so, in what society? Which is least/most likely to work and which is least/most likely to happen? If the proper conditions were already standing, would either be beneficial to the United States?

Note: Please keep capitalism out of the equation as much as possible, otherwise the discussion may expand further than intended. This is meant to be a discussion of two stigmatized economic systems to encourage deeper thought and discussion.