Another might argue that markets quite often fail, rather than produce the efficiencies they should in the ideal world, let alone the socially optimal results.
That's what we're talking about when we say that market forces may lead to inefficiencies. Few people deny the existence of market failure, but too many people advocate for government regulation to fix market failure while denying that precisely the same phenomenon occurs with government. It's appropriately called http://en.wikipedia.org/wiki/Government_failure.
