I know some common metrics include employment data, population, avg income, breakdown of neighborhoods etc but I was wondering to get a slightly more comprehensive list. 

Now I see that probably at least 20% of the population in my area are real estate investors! 

Median annual household income, population levels and increasing, unemployment rates, traffic counts for the main road etc. are things among many looked at.Renting it out for the house versus break even with taxes is a waiting game until it is developed.

. - New product supply - population growth - job growth - cost of construction - cost of landBasically job/population growth coupled with barriers to entry will help drive rents. 

It has more people than 43 states, and on its own would be the 88th most populous country in the world, ahead of Sweden or Austria, for example.""

These look more to valuations based on average square footage, land size, age and compared to larger population sizes of housing inventory.

Got my chips on metro PHX continuing to grow population long term. 

Are there any places in the U.S. that defy this rule, with consistent job and population growth, rising prices, and solid cashflow for rental properties?  

 :)  The neighborhood has a feral cat population and my tenants keep putting out milk for them and compromising our screening barriers.  

Population increase, low crime rates, good schools, property mgmt, and, oh yeah... positive cash flow