Where does spiral collide?

A self-reinforcing feedback loop in which falling prices and heavy debt drive each other downward: as prices fall, the real weight of existing debt rises, which forces distress selling that pushes prices lower still. Fisher's 1933 The Debt-Deflation Theory of Great Depressions laid out this chain, in which liquidation, falling asset values, and shrinking spending feed back on one another; the same shape appears in reverse in the wage-price spiral, where rising wages and rising prices chase each other upward. The referent is a macroeconomic feedback loop in prices, debt, and output, tracked through price indexes and debt levels, not a loop of opinion, a mathematical curve, or a growth pattern in plants.[1]

Unit

One round of the feedback loop linking a change in prices to a change in the real debt burden

Recovery means

The loop is broken by reflation of the price level or by policy that halts distress selling

Measured by

Traced through price indexes, aggregate debt, and output over a downturn, and modeled as a system of mutually reinforcing relationships

A plane curve that winds around a fixed center while steadily moving away from it, fixed by a polar equation that relates the radius to the angle. In the Archimedean spiral the radius grows in proportion to the angle, written r = a·θ, so successive turns are evenly spaced; in the logarithmic (equiangular) spiral the radius grows by a constant factor with each turn, written r = a·e^(b·θ), so the curve keeps the same shape as it grows. Lawrence's 1972 A Catalog of Special Plane Curves gathers these definitions and their properties. The referent is an exact geometric object set by an equation, not a social feedback loop, a price spiral, or a biological growth pattern.[2]

Unit

A single curve fixed by its polar equation and its constants

Recovery means

Not applicable

Measured by

Specified exactly by its polar equation and drawn or plotted from the values of its constants

The spiral arrangement of leaves, seeds, or florets around a plant stem or head, in which each new part appears at a nearly constant turn from the one before, close to the golden angle of about 137.5 degrees, producing the interlocking spirals seen in sunflower heads and pinecones. Douady and Couder's 1992 Phyllotaxis as a physical self-organized growth process showed by experiment and model how this pattern arises from the physics of how new parts form and push away from their neighbors. The referent is a growth pattern in living tissue, counted by the numbers of visible spiral rows, and it is unrelated to a loop of opinion, a feedback loop in prices, or an equation in geometry.[3]

Unit

The angular placement of successive plant parts, and the counts of visible spiral rows

Recovery means

Not applicable

Measured by

Quantified by the turn angle between successive parts and by counting the clockwise and counterclockwise spirals, which are often consecutive Fibonacci numbers