I personally prefer The Law of Fives: "ALL THINGS HAPPEN IN FIVES, OR ARE DIVISIBLE BY OR ARE MULTIPLES OF FIVE, OR ARE SOMEHOW DIRECTLY OR INDIRECTLY APPROPRIATE TO 5."
With the corollary: "I find the Law of Fives to be more and more manifest the harder I look."
cf. Foucault's Pendulum; the entire novel.
Given that Munroe has solved the problem of Friendly AI in today's xkcd, I think we can rest assured that concepts like "economy" have a near 100% chance of being moot by 2039.