fiscal stimulus: pros and cons

figuring out arguments for fiscal policy (from right and left):

John Cochrane (Chicago):
http://faculty.chicagobooth.edu/john.cochrane/research/Papers/fiscal2.htm

Robert Barro (Harvard):
http://online.wsj.com/article/SB123258618204604599.html

Paul Krugman:
http://www.nytimes.com/2009/01/26/opinion/26krugman.html?partner=rssnyt&emc=rss

Greg Mankiw:
http://gregmankiw.blogspot.com/2009/02/my-preferred-fiscal-stimulus.html

and an argument for the state of fiscal policy research: http://freakonomics.blogs.nytimes.com/2009/01/28/on-the-failure-of-macroeconomists/

p.s.
and an opinion with which i agree: http://www.economist.com/blogs/freeexchange/2009/02/the_alternative_to_econoblogge.cfm#list-comments