Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Why are residential investment properties owned by non-professional investors and not large corporations?
Economy of scale on one side versus "person monetizing an illliquid asset" on the other.  Most multifamily rental buildings are owned by professional real estate investors (as well as individuals growing an empire to become a professional real estate investor whom I will count in this group).  The rental difference between a 2000 Sq foot two bedroom apartment and 2000 Sq foot two bedroom standalone house is not large.  The construction cost per square foot for a standalone house is higher than for a multifamily building (of similar height and materials).  Maintenance calls, landscaping, and new roofs, dealing with permits and inspections, etc are much more efficient with multifamily properties.  On the supply side, most single family rentals tend to be the nonprofessional single property owner because they happen to already own the place, and for one reason or another a. Don't want to sell and b. Want to gain cash flow on the asset.