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?

No formula can be accurate across the board because even “cookie cutter” properties next store to each other differ as to view, location to the street, topography of the land, lot size, physical condition of the property, past remodeling, quality of the mechanical systems, sunlight, utility bills, past use, etc.  

I don't know the exact formulas but I do know that this is definitely used in the determination of the tax for the commercial property. 

Both of these hypotheticals would adjust slightly due to the PMT formula with excel.

Formula & Components DSCR Formula: Net Operating Income (NOI): Income after operating expenses (excluding debt service).

The mathematical formula is 5:1.

I've completed over 20 BRRRRs in the Birmingham market and help out-of-state investors do the same.The key is to work the formula backwards.

For some reason BP doesn't have this formula on this site. 

If you don't want to split it by some formula, such as number of people, you could always charge a flat rate.  

My current formula is very shaky, and I want to present accurate numbers.