I don't know about "economist," but if we are once again venturing  
out into "political economy" and "economics" as we do every so  
often (did we ever start a "FAQ"?), then Peter Groenewegen is the  
source on this, though somebody's student is probably disputing  
his stories (like happened with Groenewegen's student  
Aspromourgos on "neoclassical").  Start with Groenwegen's  
Palgrave entry "'political economy' and 'economics'."  That's one  
entry, with each term in quotes.   
 
Mat Forstater