That’s an idea that keeps coming back and back and back. The rationale is to allow families to get out of public schools by making private school alternatives more affordable. But in this Freeman piece, Jenna Robinson points out that we’ve been doing pretty much the same thing for years in higher education and the result has been constantly rising costs. Once school officials know that prospective customers have more money in their pockets, they’re likely to spend more money and capture the government’s subvention. They’ll raise tuition, and then the cry will go up that the voucher amount must be raised to keep school “affordable.”