The only things that seem to be left are the garbage that nobody wants. I don't know why, but it seems to be a red flag of sorts to me.
Definitely keep an eye out for anomalies. They might not be significant, but your own eyewitness is a good way to validate, or not, theory regarding what is happening at any one stage.
For example, during the housing bubble, I knew that despite reassurances to the contrary (didn't Greenspan specifically say "no housing bubble"?), houses were being sold to people who obviously could not afford them. Houses in the economically depressed immigrant neighborhood where I used to live were going for $3/4 million to recent working class immigrants.
