Trade-gravity board

Now · Aarambam

A teaching specification of the classic gravity model with cited Head & Mayer 2014 coefficients. Each slider names a real lawful-corridor factor with a published proxy and a δ from the literature.

Becoming · Nilaiththanmai

An era-week-archived snapshot the diaspora and any researcher can audit, fork, or improve.

T_ij  =  G · ( M_i^α · M_j^β ) / D_ij^γ  ·  exp( Σ_k  δ_k · Z_k )

Diaspora density· புலம்பெயர்Z = 0.82

δ = 0.74 · Head & Mayer 2014; ONS Census 2021

Common-law overlap· பொது சட்டம்Z = 0.91

δ = 0.55 · Head & Mayer 2014; CEPII GeoDist

English-language depth· ஆங்கிலம்Z = 0.78

δ = 0.62 · EF EPI 2024

Treaty overlap· ஒப்பந்தம்Z = 0.61

δ = 0.41 · UK Treaties Online

GSP+ / DCTS status· GSP+Z = 0.55

δ = 0.49 · UK DCTS 2023; EU GSP+ Regulation

Accountability compliance· பொறுப்புக்கூறல்Z = 0.38

δ = 0.33 · OHCHR HRC mandates

Lawful corridor potential37.8%

Illustrative reading on the unit interval, derived from a Tinbergen-style gravity specification with cited coefficients. The number is a teaching artefact — not a forecast, not a tradeable signal, not a policy ranking.

What this is

A Tinbergen gravity equation with named, cited coefficients.
A slider surface so the reader audits sensitivity, not us.
A descriptive lawful-corridor band on the unit interval.

What this is not

A forecast of bilateral trade volumes.
A tradeable or investable signal.
A live data feed of any kind.

Provenance · Tier-A

Observatory · Gravity · Index · Coupling

Instrument II · Civic-Axis composite index