George DeMartino asked whether there is a subfield called "ethics for  
economists."  I interpret this as asking "have economists defined something that  
might be called economic malpractice?"   
 
Two points seem to be relevant to the latter question. 
 
First, all those discussions about the scope and limit of economics starting  
with  Adam Smith's "man of system" who imagines that he can arrange the  
members of society as the hand arranges pieces on a chess board and spilling into the 19th
century writings of Senior,Cairnes, J. Neville Keynes are relevant
here.  In the 20th century, von Mises and later Hayek spill much ink about the  
pretensions of economists who think that they can plan and predict social  
outcomes.  I know that Mises in Human Action has a section on economics as a  
profession and presumably discusses the responsibilities of an economist.  Even more
recent are the swell books by David Colander comparing economists to garbage collectors
and finding the latter group more useful to society.
 
Second, Professor Grampp has remarked in several writings about economists  
giving advice to leaders as if the leaders can simply trump or ignore the  
democratic process and do what economists's recommend.  Grampp's thoughts date back to the
1960s and predate the more recent discussion about economists who
pretend that they can judge economic events from some privileged position "outside" the
economy when all the time they are as much a part of everyday social and economic life as
the person who drives the city bus.
 
I hope this helps.  I apologize if I have misunderstood the intent of the  
question. 
 
Laurence Moss