Advocates of vouchers define the education system as something that parents consume. In their minds, if parents were given vouchers that were equivalent to money and could "spend" these vouchers on the school they wanted their child to attend, schools would respond to demand for education like companies respond to market demand.
I'd argue that the parents are not the best decision-makers about how to shape schools: teachers are. In that light, perhaps we should set up a system in which teachers had the vouchers and could spend them as they wished. Imagine what it would be like.
Right now schools spend roughly $6,000 per student per year. Now, give that money to teachers. If they had, say, 20 students they'd get $120,000. But here's the catch. From that money, they'd have to lease or rent a building where they could teach, hire janitors for cleaning, hire administrators and assistants to help them, etc. Now, the entire administrative structure would be directed towards helping teachers to succeed. Rather than focus on pleasing the folks in Sacramento (or Little Rock or Albany), administrators would, of necessity, focus on helping teachers in the classroom. If the teacher(s) did not see any value in the school psychologist, teaching materials, or school principal, those entities would get no money. The ones that did help would receive money - perhaps even more than they do now.
In the spirit of full disclosure, I should say that I'm married to a teacher. The neighborhood she teaches in is lower income and she regularly brings home stories of her frustration with nonresponsive administrators or supposed helpers with teaching, cleaning, etc. It would be a very different matter if all these resources that were supposedly directed towards helping children learn were dependent on her for their funding. The level of responsiveness would have to go up.
One of the many advantages to this kind of system would be that you'd have the equivalent of about 6 million businesses (there are more than 6 million teachers in the US) all innovating and creating demand for high-value added resources and materials. What this would do to the level of innovation could be amazing.