Does anyone else believe in Austrian Economics & follow Peter Schiff & Lew Rockwell & think that when the everything bubble pops in next couple years (we are already in 2nd longest expansion ever) that we ...

I know the "50% rule" is bandied about as gospel here in the forums, but haven't seen any actual, hard data that says that operating expenses tend to be ~50% of gross rent income. I'd like to verify this number is, in...