You need proof that a child growing up with quality care and a quality social/cultural environment is more likely to be able to function and "succeed" in life as an adult?
I would be interested how research defines this "high quality social/cultural environments" and how it controls for factors such as genetics, family cultural and financial background, etc. Separated twin studies would probably be ideal (but I'm not an expert in the field).
I'm not sure how we expect a 1:6 ratio to be "cheap", even before factoring in costs like real estate.