FTB-C000280 / Statistical method

Diffusion Index

Diffusion Index summarizes the balance of increases, unchanged observations, and decreases across a population.

Also known asdiffusion measure

Definitions

In plain terms

Under a widely used convention, increases receive one, unchanged observations one half, and decreases zero before scaling to 100.

Technical

A reproducible index fixes population, classification signal, tolerance for unchanged, weights, denominator, time, and missing values.

Scope

A value above 50 describes breadth under the chosen rule; it does not guarantee economic or market growth.

Formula

Diffusion index = 100 * (N_up + 0.5 * N_unchanged) / N_eligible
LaTeX: DI=100\frac{N_{up}+0.5N_{unchanged}}{N_{eligible}}
SymbolMeaningUnit
N_upeligible observations classified as increasingobservations
N_unchangedeligible observations classified as unchangedobservations
N_eligibleeligible classified observationsobservations

Output unit: percent

Examples

  • A Fintech Builder lesson can compute or identify Diffusion Index only after declaring its inputs, timing, and edge-case rules.

Common misconceptions

  • A value above 50 describes breadth under the chosen rule; it does not guarantee economic or market growth.

Concept relationships

Where this concept is used

Evidence and governance

  1. Business Cycle Indicators: Diffusion Indexes The Conference Board · first party methodology

    Supports: preferred label, short definition, technical definition, formula

    Limits: Applying the general diffusion construction to sectors or factor groups is a declared Fintech Builder adaptation.

Reviewed by
fintech-builder-batch-005
Last reviewed
2026-07-27
Next review
2027-07-27
Record status
evidence reviewed

This record is evidence-reviewed and readable, but not yet promoted to published — it is served noindex,follow and excluded from the sitemap.