The most major factor in most markets is affordability.

is there a particular formula that takes all manner of factors, (employment growth, corporation development news, barrier to entry, rental rates, wage growth, etc) into account and spits out an "invest in city X" answer?

It’s always you should change your lifestyle so they can keep theirs.

This may not seem like a big deal, but it is something that you will need to nail down and factor into your analysis.

I live outside the USA so that my money stretches further, I have better food, better lifestyle and I am out of the rat race in the USA.

MAYBE they adjust that up or down 10% depending on outside factors but they’re not checking the assessed value. 

We use these factors in this order of importance (feel free to create your own):1) Tenant pool credit score2) Location => Neighborhood3) Property condition & amenitiesClasses are not defined for the SFR industry and are relative to the area.

Danko (Author)It’s people who live a fairly conservative lifestyle and while they own  mundane type businesses or work professional type jobs (or high paying blue collar jobs) put aside a good amount of income for investment.  

In most markets owning a B&B is a lifestyle choice.

That’s a factor in getting rehab upfront.