THE MESSAGE to parents couldn't be more clear: Vote with your feet if the local public school fails to adequately educate your child. The message to school administrators in Maryland and nationwide is no less harsh: Show progress in the lowest-performing schools, or it'll cost you.

Implicit in the newly released regulations giving muscle to the sweeping federal No Child Left Behind Act is the notion, as yet unproven, that the drumbeat of parents demanding a taxpayer-supported transfer to a better education will force states to improve their failing schools. A big stick has been provided in case the theory fails: a threat that federal aid for impoverished students won't flow to districts where schools are not regularly making progress.

Thrust into an expanded role as watchdog, the Department of Education that Republicans once considered expendable is suddenly a tough-talking overseer of state standards for teacher and school quality. For Maryland and other state school districts, the painful race is on to rip up old tests and revise standards to accommodate, if not embrace, the new regulations.

The Bush administration's attempt to impose on public education a marketplace mentality -- and the mountain of new paperwork that's supposed to document how well the product is delivered -- may be creating a nightmare.

Although it promotes strong reading programs, the law does not provide a blueprint for improving schools. Thus, some teachers unions warn that lacking sound educational research to support many of its sweeping initiatives, the law cannot be predicted to succeed widely at its goal of producing better schools. Demand for change may well be increased, but supply is much harder to grow. And supply is the heart of the school choice problem.

For example: The new regulations oblige school systems to transfer children from failing and "persistently dangerous" schools to better ones. But where are the desks in the better schools for all of the eligible children? Baltimore placed 194 of 30,000 eligible for transfer this year. Make room, say the feds. With what impact on budgets, and on the stability of the receiving schools and the ability to resurrect the abandoned ones?

The new regulations also mandate that teachers and aides in schools receiving Title I federal aid must be highly qualified. Yet national studies consistently show that the teachers with the strongest credentials migrate to the wealthier public schools; needy school districts already struggle to attract the best teachers. No solution is offered.

In schools posting three years of failing scores, Title I funds -- which the law did increase -- must be used to provide remedial tutoring. This is a boon for the needy students, to be sure, and for the entrepreneurs who provide such services. Parents must request it (again, this is about choice), but if they don't, as has happened in at least one city launching its program, will the schools be penalized?

Many school administrators believe the expectations -- and the timetables -- to be unrealistic, no matter how laudable the intentions of No Child Left Behind. Without a doubt, consequences are deserved by school systems that have failed year after year, despite significant local and federal investments, to close the achievement gap between their poorest and richest children. But in the rush to change the way Americans think about education, federal officials would do better to show the way to best practices, and then push states to impose tougher sanctions on the school systems that aren't doing their jobs, instead of threatening penalties that would take away aid from needy children.