Wisconsin bureaucrats will cushion the bump when the Milwaukee Parental Choice Program outgrows its enrollment ceiling this year, the Milwaukee Journal-Sentinel predicted recently. The MPCP now serves almost 15,000 of the city’s youngest residents. This is nearly the legal maximum of 15 percent of students enrolled in the Milwaukee public schools.

If the relevant regulators were sticklers for arithmetic, a run on vouchers this summer would be likely. But the Department of Public Instruction will reportedly employ fuzzy math to allow open enrollment in MPCP through the end of August, even if the legal cap is exceeded slightly.

The choice law’s likely reprieve surfaced in a pot aggressively stirred by the Journal-Sentinel in a recent series that covered the MPCP while questioning its premises. While the survey strives for some objectivity, noting that many participating schools are excellent, its central thesis is profoundly anti-choice. The program proves, the paper says, that economic theory is wrong to predict that parents will choose well.

The Journal-Sentinel reporters spent seven days measuring the MPCP against an irrelevant standard — perfection — and finding that it falls short. Some participating schools are bad, they reveal, mystifying the mystics who think markets are perfect.

A handful of the schools discussed are clearly sub-par. Even voucher advocate Howard Fuller wrote to DPI to encourage investigation of obvious negligence. But the paper’s own reporting inadvertently indicates that the bad apples are sorted out fast by market forces.

The Journal-Sentinel highlighted seven schools that left “positive impressions” and seven others that appeared to be “questionable scenes.”

Most schools that left positive impressions with visiting journalists had stood the test of time. Five of the schools praised by the newspaper are seven or eight year veterans of the MPCP. Only one school on the list, the Malaika Early Learning Center, was new this year.

By contrast, the “questionable scenes” were overwhelmingly new. Three of the seven listed schools were in their first year, and another three had between two and four years in the MPCP. The only well-established school to receive a thumbs down — the Harambee Community School — is being torn apart by financial mismanagement, not bad teaching or classroom disorder.

“Weaker schools in the choice program manage to survive — in some cases, even thrive,” the paper asserts. But its own facts suggest the opposite. They suggest that the market is working. Schools that have survived five years in the MPCP appeared well run to visiting journalists.

Moreover, enrollment trends supplied by Public Policy Forum show that parents continue to separate wheat from chaff. Hickman’s Academy Preparatory School and the Hope Christian School, both on the Journal-Sentinel’s good list, posted some of the MPCP’s largest student enrollment gains.

The Journal-Sentinel’s other effort to puncture the Perfect Market Myth is an expose of the processes by which parents choose schools. “Gut Instinct Guides Parents’ Choices,” reporters complain.

Parents rely on informal networks when picking schools, the paper reports, such as a church affiliation or a referral from a family member. “The best thing is word of mouth,” Principal Paul Hohl of the St. Sebastian School told a reporter.

Professor Paul Teske of the University of Colorado dismissed the referral system as “just psychological attachment issues.” “If you know a teacher or a person you like at a school,” he told the Journal-Sentinel, “you get a feeling of social attachment.”

But referrals are a time-tested market mechanism for making complicated choices well. We choose doctors, dentists, and lawyers in this way precisely because it is hard to represent their quality — or their suitability for us — by any simple metric.

The paper implies that parents should be choosing schools based on more objective criteria such as test scores, and it laments their lack of passion for playing by the numbers.

But school average scores notoriously reveal more about the backgrounds of children who attend a school than they do about how much those children are learning. A school that caters largely to impoverished children will have lower scores than a mostly middle class school even if those children are showing great improvement over time.

More critically, average scores reveal nothing at all about how any one child will do in a particular school. The foundational principle of school choice is that different children learn differently. One child may thrive in a non-structured environment. Another will learn more in a school with lower average scores but a more disciplined approach.

The Journal-Sentinel quotes Dorothy Smith, who chose three different schools for her children based on their different needs. “Some kids need a little more umph than other kids,” she sensibly observed.

Parents know this, and they aren’t looking for the school with the highest scoring students. They are looking for the school at which their child will score the highest. That these are two completely different things is what the Journal-Sentinel — and all those who think testing and sanctions can outperform choice — seem not to understand.

The series ends with a call for “clearer and better answers” about how the MPCP schools are serving students, the mantra of those who want to condition the program’s expansion on the addition of bureaucratic weights and measures.

If the Journal-Sentinel reporters are right, then perhaps 10 percent of the MPCP schools are not doing the job they might. But over 20 percent of Milwaukee Public Schools are now “in need of improvement” under the No Child Left Behind Act. If these numbers mean something, they mean that a parent-driven market is about twice as good at eliminating poor schools as the public system. If they mean nothing, then parents are right to choose schools in a subtler, more subjective way.

Milwaukee’s voucher kids are doing all right. The market is a dynamic process, and school closings, like flu symptoms, are a sign that the MPCP naturally resists poor quality. Wisconsin lawmakers should ease the enrollment cap on its flagship school choice law without regulating away the variety it needs to succeed.