Landlord Market Analysis/Statistics Help

[Chad Bean]

I'm conducting research for an MBA project and am trying to do a bottom-up analysis of the residential real estate, property management market and what percentage of that market is comprised of properties with out-of-state land lords.

The very specific question I am looking to answer is how many landlords own rental properties out of state, and how much do those landlords pay to management companies annually?

This is a smart bunch so any sources or even logical approaches as to how one might find these numbers via research would be greatly appreciated :)

I've done two separate top-down analysis based on census data, IRS data, and surveys, but those differ quite bit.