I'm just a dumb pilot....
...but every time I read something like this RBS note, I think back to Goldman saying oil would hit $200/bbl in 2008 and other investment banks saying the Dow was going to 5000 in 2009.
I also kinda feel much of this is a self-fulfilling prophecy; bankers say "The sky is falling!" and consumers stop spending because they have been told the economy is going down...and the new drop in consumer consumption at best deepens and at worst actually precipitates the very economic drop bankers initially called.