I can’t tell you how many times I have heard supporters of arts education say: “we need a research project that will prove beyond any doubt what we already know about the benefits of arts education. Then we will really make headway.”
It’s the silver bullet theory. In this case, it’s the incontrovertible piece of research that will flip the switch. 
The silver bullet theory has been at play in the movements: small schools, charter schools, vouchers, accountability, etc.
Okay, here’s Diane Ravitch taking on the silver bullet theory that the Gates Foundation bought into for a cool $2 billion. That not a typo. Yup, $2 billion.
Click her to read Diane Ravitch in Forbes.com on Bill Gates And His Silver Bullet
I am still hoping that the Gates Foundation, wonderful as it is, will acknowledge and make a statement on the importance of the arts. A position on the arts appears to be significantly absent among their initiatives to date.
It is also hoped they will put in place financial incentives for community based and education centered quality of life measures that provide access to the arts for all citizens.
This is how the history of a civilization is recorded, through its arts. I, personally, am waiting and hoping to see this realized by the Gates family and foundation.