Bruce Baker, esteemed school finance researcher and a good friend of mine, has access to national and state data on private school per pupil expenditures. He kindly ran some Texas numbers for us and has them at:
He found that the voucher proposed by Rep. Miller would NOT cover the per pupil costs for almost all private schools in Texas. I found that the voucher would not even cover the costs of tuition at most schools.
See my other post here for details:
https://fullerlook.wordpress.com/2011/05/18/vouchers/
While the researchers supporting the voucher plan assume the vouchers will increase the number of students attending existing private schools (based on one study from 1990 that preceded charter schools, thus is no longer relevant since research since then has shown charter school existence decreases private school enrollment), there are two more likely outcomes:
1) Little change in who enrolls in private schools, but a huge transfer of money to the many wealthy families who already send their children to elite private schools;
and/or,
2) An increase in low-cost, religious schools or schools run by those seeking to make a profit from families with students struggling academically.
We have seen what happens with number two since we have had a number of terrible charter schools that address the same population, many of which have had serious financial problems and instances of fraud and embezzlement.
But, if people like Rep. Miller want more choice–they already have it in the almost 500 charter schools across the state. And the charter schools are FREE to the families, are NOT affiliated with any religious group, and I believe are required to provide transportation or at least many do provide transportation at no cost.
Since we are seeing a HUGE proliferation of charter schools, why do we even need private schools?
For families who feel their children are not in the right setting, they can simply move to a charter school. Transferring huge sums of money to religious schools and the wealthy simply makes no sense whatsoever.
Vouchers are a terrible idea in practice. They DO NOT improve achievement except for inner-city African American student in just a few cities.
So, we would be transferring huge sums of money out of the public education system that already does not have enough money to meet the needs of all students simply to satisfy those who believe the free market is always better (which research clearly shows is NOT the case) or who want to destroy public education for ideological reasons.
A "Fuller" Look at Education Issues 
Joe Smith
May 20, 2011
Exactly – This is on target. I have noticed that the availability of transferring to various area schools is really only available to those that can take advantage of the opportunity. Usually dependent on those that have transportation available.
schoolfinance101
May 20, 2011
Actually, the fun part about my database is that it has the actual expenditures per pupil (expenditures from IRS 990s, and enrollments from NCES Private School Survey), and not tuition. Expenditure is a much more relevant figure for these comparisons. Tuition data are available for private schools in the Schools and Staffing Surveys. I’ll do something with that at a later point in time.