Eugenicists always reveal their real motivations when they start applying words like "superior", "competent", and "productive" to classes of people (and you have used all three just in this thread!). Since a family of four who makes under $34,000 per year doesn't pay any federal taxes and is therefore taking in far more than they contribute, let's just sterilize everyone making less than that. They aren't "productive", right? That will leave more room in society for your kind of "productive" people.
Needless to say, when you subsidize something you get more of it: deliberately or otherwise, that is a eugenic process, and a pretty ugly one, too. I'd like to that reversed or, at least, neutralized.
Yeah, forget sterilization. It takes too long to see the results. Let's just round them up and put them in death camps.