Earlier this week, Doug Tuthill, the president of Step Up for Students, argued that Common Core can help school choice. Tuthill is a champion of school choice whose organization has helped hundreds of thousands of Florida students attend their preferred schools. That’s why it is all the more disappointing to see him advocating for a policy that would undermine the very system of diverse educational options that he’s worked tirelessly to promote.

In Tuthill’s view, common standards merely “serve the same function as the operating systems in computers or smart phones” in that they provide a common platform that’s open to an “endless supply” of different applications (curricula, lesson plans, activities, etc.) that can be customized by users.

But Common Core is not just an open-platform operating system. As Chester Finn of the Thomas B. Fordham Foundation has written, standards-based accountability requires a “tripod of standards, testing, and accountability.” My colleague, Neal McCluskey, has pointed out that a system of national standards like Common Core requires a “national tripod”: “all schools must use the same standards and tests to compare how all kids are doing, and there must be uniform punishments for schools that do not do well.”

Tuthill claims there’s nothing to fear because private schools and their parents “value their autonomy. They will oppose government efforts to mandate curriculum or instructional strategies.” But the government doesn’t have to mandate a curriculum to control content. When standards are tied to tests by which a school’s performance is evaluated, schools will have little choice but to conform. The tests will de facto dictate content: what concepts are taught when and perhaps even how. As James Shuls of the Show-Me Institute has written:

The fact is that curriculum standards don’t tell teachers how to teach in the same way that a high jump bar doesn’t tell a jumper how to jump. You could theoretically jump over a high jump bar in whatever way you would like; but because of how the jump is structured there is a clear advantage to doing the old Fosbury Flop.

Rather than providing a mere operating system, it’s as though Apple told app-designers they could make any kind of app they want so long as all the apps perform the same basic function, operate at the same speed, and cost the same amount. Of course, they’re welcome to vary the color scheme.

This wouldn’t be a concern if Common Core were truly “voluntary” for private schools, as Tuthill asserts it is. If someone doesn’t like the iPhone, at least they can switch to Android, but there will be no viable alternative to Common Core. As Tuthill explains elsewhere in his post:

That our country’s two primary college entrance exams, the ACT and SAT, are aligning their assessments to Common Core is also motivating private schools and their parents to embrace these standards. Private school parents want their children to be college ready when they leave high school, and private school administrators know this. Consequently, private schools are embracing the new standards to meet parental expectations.

This is more than mere “motivating.” If the SAT and ACT are aligned to Common Core, then private schools will have little choice but to align as well. Tuthill calls this “voluntary” for private schools but the choice is between adopting Common Core or putting your school’s students at a disadvantage on these tests relative to students from other schools. Of course, lower average performance on tests like the SAT means a decreased probability of students getting into their preferred college, which will translate into fewer students attending your school.

In other words, parents and schools are not “embracing” the standards because they think they’re good, but rather because the standards are becoming the only viable path for their children to go to a good college. “If college entrance exams are Common-Core-ized,” explained Greg Forster, “it will be virtually impossible for private schools and homeschoolers to maintain any kind of alternative to the One Best Way.” That wouldn’t be a problem if there were a One Best Way in education, but there isn’t.

Tuthill also argues that Common Core will make it easier for students to switch schools. “Knowing that many schools are using the same operating system (i.e., the same standards) can help reassure parents that their children are able to receive a seamless, high quality education from diverse providers.”

What Tuthill calls “diverse providers” will merely be different schools claiming to offer a better quality version of almost the exact same product. Switching schools may become easier, but that is a very high price to pay at the expense of true diversity of options. As Professor Jay P. Greene of the University of Arkansas has explained:

Common Core is inducing reformers to ignore and even denigrate choice-based reforms because they have to deny one of the central arguments for choice — that there is a legitimate diversity of views on how and what our children should be taught that choice can help address. If Common Core folks have any support left for choice it is to allow parents to choose the school that can best implement the centrally determined education content. You can choose which McDonalds franchise you frequent so that they can compete to make the best Big Mac for you, but you are out of luck if you prefer pizza.

Rather than complement school choice, Common Core undermines it. To address the diverse needs of diverse children, we should be supporting an education system that provides a truly diverse array of options and entrusting parents to decide which option best meets the individual needs of their children. In exerting tremendous pressure on private schools to conform, Common Core would reduce the number and diversity of those options. Private schools and school choice advocates should consider very carefully where Common Core is taking us. There is still time to resist.