Actually, no, the data shows that it is also often more efficient as well. Remember, if you've got to take a 10% share to give to shareholders, you're already more inefficient, even if you do things precisely the same way. So, for performing X task for Y money, there are many instances of the public sector being more efficient (and also effective).
And @zmaj, you seem to forget that that money in your pocket is there because of public goods you benefit from. You know how to read. You're using an internet and computers developed from science and technology developed largely for the public good. You eat food shipped by roads. You breath air, etc. etc.
And actually, yes, evil trolls sitting on a hoard of treasure is actually a pretty good description of the US economy. the 400 richest Americans hold more wealth than the bottom 194 million combined. So, actually, yeah, we're a society that economically isn't that distinguishable from feudalism, really. A tiny fraction have basically everything, and the rest get nothing.