The CBO, in its report, said that states that took advantage of waivers offered in the proposed law could perversely end up blowing up their insurance markets, leaving spiraling costs for people with preexisting conditions.

Glenn Kessler, “Virginia lawmaker promises ‘honest truth’ in misleading ad”  Washington Post, 24 October 2018

Thanks to the parsimony of the press, we Americans are supposed to spell spiralling with only one “L”, just like traveller and a bunch of other words which the English remember how to spell.

What I want to talk about today, though, is the meaning of the word spiralling.  The writer quoted above seems to think that it means “going up and up”, and that, indeed, is how it’s often used by our paid praters.  But there’s nothing inherently upward about a spiral.

Image result for spiral animated gif

From https://www.instructables.com/id/MathVision/

A spiral can go (or appear to go) upwards, downwards, inwards, outwards, or nowhere at all.  W. B. Yeats imagined human history as a system of upward and downward conical spirals, which he called “gyres” (with a hard “G” for some reason).

From http://www.faena.com/aleph/articles/a-brief-approach-to-w-b-yeats-lunar-system/

Kessler, in the quotation above, probably just means “rising”, so “spiraling” for him is probably a dead metaphor; although maybe he really means sky-rocketingi.e., going up very rapidly.  (I originally suggested soaring, but that word doesn’t strictly suggest speed, only great height.  Things that actually soar, like birds and gliders, do it in rather a leisurely way, I think.)

One could still use spiralling metaphorically (with a preposition to indicate direction), to describe costs that go gradually up or down (because they’re going around and around at the same time, if that were possible), but that’s problematic because the verb (to spiral) seems somehow to suggest speed—perhaps increasing speed, as in “spiralling out of control”.  I don’t know where that image comes from.