As Vox points out, it appears the leaders of the Massachusetts government could use one:
Apparently the Law of Supply and Demand still comes as a bit of a shock to some. What, you mean you can't subsidize the cost of health care without increasing the demand for it?
Now in Massachusetts, in an unintended consequence of universal coverage, the imbalance is being exacerbated by the state’s new law requiring residents to have health insurance.
They couldn't figure this out in California, and, sadly, they aren't going to figure it out any time soon. If you follow this line of reasoning to its logical conclusion, the obvious answer to today's economic problems is to make all goods and services free! After all, it worked so well for the hippies.


not fit
This just affirms my assertion that democracy cannot work (or at least not for very long). People are just too stupid, be they elected, appointed, or voting. I cannot see how a man can be considered fit for governing in any capacity without a decent if not thorough understanding of this most basic, immutable law of economics. I also don't see how a man can be considered fit to elect his own leaders if he doesn't get this concept.
If democracy is to be undertaken at all (and I think it should not be), then voting and serving need to be severely limited to those rare few who can pass a basic test of competence--one that includes a clear demonstration of understanding of Supply and Demand. Don't be shocked at my desire to severely limit voting. We test everybody who wants to drive for some basic competence. The worst a bad driver could do is kill a handful of people. The worst a bad voter could do is elect is moron, or a sociopathic moron, and the worst such a moron can do is destroy the bulk of the planet in a nuclear holocaust. Short of this, he could destroy our economy, alienate any allies, make enemies of the rest of the world, and institute a police state here at home. Those who send such a man into office share the responsibility for such atrocities. Surely these dire consequences warrant some basic competence for those who vote and those who are elected or appointed to office.
Would anyone like to propose such a test here? We can start with some broad terms. First, of course, we should require a demonstration of competence with the Law of Supply and Demand. What's next?