Although there may not be a great deal of research on the subject, how about these facts:

In the last three years - we have looked at over 100 nursing home cases, taken over 30 - and not one was against a non-profit nursing home. So we are finding that the 60% of nursing homes that are for profit in Virginia, are responsible for almost all of the negligent acts - which lead to lawsuits.

in 2001, studies showed Investor-owned facilities averaged 5.89 MEDICARE deficiencies per home, 46.5% higher than nonprofit facilities and 43.0% higher than public facilities. What else is more likely to go wrong in a for-profit facility?

If they must make money, you may likely see nurse staffing at lower numbers, less spent on meals, less spent on staff training.

It may not be scientific - but our experience is the for-profit facilities owned by investors or even family companies, provide worse care than public or non-profit nursing homes.