How about the fallacy (or whatever, respecting some recent comments)   
of "market failure."   Markets are social constructs (society agrees   
on and enforces what constitutes property, contract, tort, etc.);   
therefore markets must serve socially desirable outcomes.  If   
"markets" fail to do so, what or who has failed?  The "market" or the   
society that frame it?  
  
Fred Carstensen