Pat Gunning wrote:
"The whole idea of a shock seems a bit weird, doesn't it? Why call a 
change in market supply a "shift" and a change in aggregate supply a 
"shock?" This language seems more journalistic than scientific."


The thinking, I suspect, goes back to Frisch's "Propagation and Impulse 
Problems in Dynamic Economics" (in  /Economic Essays in Honor of Gustav 
Cassel/, 1933).  As far as I can tell, the language did not become 
widespread until the mid-1970s.  The oldest JSTOR entry for "demand 
shock" is Lucas's (1975) "An Equilibrium Model of the Business Cycle" 
(JPE) ; and the oldest entry for "supply shock" is Gordon's "Alternative 
Responses to External Supply Shocks" (Brookings Papers, 1975).  Both 
write as if the terminology is already established.


Pat Gunning wrote:
"By the way, didn't you say that you are writing a macro text? How do 
you treat the AD/AS stuff in your text?"


Anyone is welcome to look at my textbook in progress:  
http://econ.duke.edu/~kdh9

Kevin Hoover