In connection with a school voucher proposal, Geneva Overholser seems to agree that "we don't know what the effect of competition is going to be, because we haven't really tried it" [op-ed, Sept. 20]. Maybe we haven't, but Chile has for almost 20 years, and that nation's voucher experiment has not worked.

Stanford researchers Martin Carnoy and Patrick McEwan found that vouchers drained students from better-educated families from the public schools and did not improve the public schools. The central government's reform efforts, on the other hand, did lead to school improvements. Mr. Carnoy, a self-described liberal who was hoping that the vouchers would give poor people options, says that if markets work, a market in Chile should work the same way as markets anywhere else.

In connection with the Milwaukee and Cleveland voucher experiments in this country, Ms. Overholser writes that "preliminary indications are that student performance is strengthened." Even if this were true, the results of these hot-house experiments would provide no policymaking information for the larger system. But it is not true.

Only one researcher, Paul Peterson, has found improvement in Milwaukee. Others either found no improvement or a small, ephemeral effect. For instance, Cecilia Rouse at Princeton found a small improvement in math scores but none in reading scores. She observed that the voucher students appeared to be in the smallest classes of any of the groups studied, and small classes are known to increase achievement. If "student performance is strengthened," it might well be because of these smaller classes, not some "voucher effect."

Finally, early in her essay, Ms. Overholser notes that a fundamental objection to vouchers is that they might hurt the public schools. In the remainder of the piece she provides no information on how the proposal she is considering will avoid that.

GERALD W. BRACEY

Alexandria

I agree with Geneva Overholser: It is not fair for more affluent children to benefit from choice, when poor children who have none are stuck in a poor public school.

But are vouchers the answer? Why is it all right for some poor children to benefit from a voucher to a better school if not all of them can benefit? What assurance do we have that all the children with vouchers would be admitted to the school of their choice? What assurance do we have that these schools would do a better job? What if there is no better school (private or otherwise) in the community? These and other questions should be answered before we embrace the idea of school vouchers too tightly.

BARBARA K. FRIED

Alexandria

The Aug. 29 editorial "U-Turn on Vouchers" made much of the fact that 85 percent of the schools in Cleveland's voucher program are religious schools.

If this is The Post's concern, let's work to take down the barriers to competition so that the free market can respond with a supply of the schools families demand. If parents want religion in schools, then so be it. If there's anything I've learned in business, it's that a free market meets consumer demand.

The best way to meet the unmet educational demands of all parents is to unleash the power of the American entrepreneurial spirit. Every other sector in our society is forged by competition in a free market that encourages excellence, service and value. Education is not immune to the laws of supply and demand.

An education system defined by competition will deliver what parents want for their children, rather than what the politically powerful want from the system. As long as education remains insulated from the healthy competition that drives the rest of society, the more anachronistic and, finally, antagonistic to American society it will become.

Competition has improved every product and every industry in America. In this case, the product is the education of a child. It's time to free the system and, with it, the children.

DARLA ROMFO

President and Chief Operating Officer

Children's Scholarship Fund

New York