Even the author must recognize that a 4% real increases in college costs (after 2% inflation) cannot continue indefinitely. If that were the case, a state school that currently costs $10,000 annually would cost $500,000 annually by 2117 in today's dollars, while a private school would be a cool 2.5 million in today's dollars! Clearly, the market would correct before such a scenario ever came to pass. Even debt-funded bubbles hit a breaking point.
So the question is, how close are we to that breaking point where consumers lose their willingness to pay? I think for some less-regarded private schools, that breaking point has already been hit. Some second-tier private schools with very high tuitions have started to suffer declining enrollments. However, I think we are a long way from it with most public schools. It's also worth noting that a big driver of public school tuition inflation has been declining state support. Public support for public institutions probably won't go below zero, so there is a limit to how long those increases can be driven by declining public support.
How would they do that without divulging the test questions? To offer more than twice a year, they'd have to write quite a few more test questions, which they don't have staff for. The exam writers and graders do it as a temp gig.
They also don't have permanent test location facilities. I took the exam in the basement of a convention center. Keep in mind that most states write their own bar, and especially with smaller states, the number of takers may only be in the hundreds. Also, it may take an entire day to take an essay exam consisting of only 5-6 questions- which makes options like an adaptive exam not possible. Centralized test centers and/or an adaptive exam might work for the multistate bar exam (which is a component of every state's exam), but that's 1/2 or less of the exam.
In most states, the bars actually aren't that well funded. Despite popular belief, a lot of lawyers are far from rich, and bar dues need to be set so the public defender making $40k a year can still pay them.
"In matters of principle, stand like a rock; in matters of taste, swim with the current." -- Thomas Jefferson