Iā??ll have more to say on this subject later (a post Iā??ve been meaning to get to for a month), but let me whet your appetite: In Star Trek, there is no money. People work at what they want to, as much as they wish to. In exchange all their needs are taken care of...

In Star Trek, energy can be converted into matter at seemingly minimal cost. This matter can be any form from a rock, to a steak sandwich, to a warp nacelle...

Therefore we can see: communism can only work if you violate the laws of physics...

Also, the Ferengi, Romulans, and Dominion all have capitalist economies to some extent. And each of them has a better tech. base than the Federation...