model 07 — ecological stock-flow consistent · define-uk · UK · experimental

Climate policy meets the UK financial system.

An adapter for DEFINE-UK, the ecological stock-flow consistent model of the UK macrofinancial system. Experimental: the baseline macro block replicates the manual, and scenario deltas are gated on the published scenario definitions — deltas only, never levels.

with the microsimulation

Connected to the microsimulation — experimentally, deltas in, incidence out.

define_scenario_incidence turns a scenario's household income deltas into a pre-tax earnings overlay on PolicyEngine's UK population — the same EconomicAssumptions pattern as the SVAR, FRB/US and HANK bridges — so a climate-policy scenario reads household by household, through the automatic stabilizers. The deltas are produced locally and only the numbers travel, never the unlicensed upstream code; the output is a delta, not a forecast; and score_reform still refuses this model.

01 — what it is

An ecological stock-flow consistent model of the UK.

DEFINE-UK is the ecological stock-flow consistent model of the UK by George, Dafermos, Nikolaidi and co-authors (define-model.org/define-uk): the macrofinancial system and its environmental impacts in one closed accounting system, with UK-specific housing and power-sector blocks. Version 1.1 (April 2026) added the regulation policies.

The upstream repository is public but carries no licence, so we vendor nothing: our adapter fetches it at a pinned commit (846081a) and runs it unmodified, in R. The scenario surface reads a cached full notebook run (2026-08-01, R 4.3.0). How it works →

02 — status and limits

Validated to the ceiling the publications allow. Deltas only.

Experimental; partial replication — deltas only, never levels. The baseline macro block replicates the manual's Table 4 and every scenario toggles exactly its published policy switches, but no numeric v1.1 scenario results are published, so those gates are the ceiling.

Two things do not pass. The baseline emissions path runs below the published table — −3.5% in 2025, widening to −23.3% by 2040 — pinned at the observed ratios and raised with the authors. And the baseline sits far from official outturns: 2025 growth 4.66% against an ONS 1.31%, 2024 emissions 401.5 MtCO2e against a DESNZ 371 — a gap computed and regression-tested, not asserted. Hence deltas only.

Two more things to know before quoting a number

The multiplier runs high. Our cumulative green-public-investment multiplier is 1.78. It is not comparable to the short-horizon published multipliers it used to sit beside: ours is cumulative to 2040, its denominator is endogenous and biases the ratio up, and a demand-led closure implies above 1 anyway. Labelled wherever a delta is served. The upstream table's own multiplier columns are unusable, and never quoted.

Nothing upstream is hosted. Hosted tools return run instructions, never results; the path to hosting is a clean-room reimplementation of the published manual.

03 — sources

The model, the paper, the adapter.

Where DEFINE-UK's inputs and outputs live
what	where
The model	define-model.org/define-uk — the DEFINE-UK 1.1 Model Manual (George & Dafermos, April 2026).
The paper	Evaluating climate policy mixes in the UK: an E-SFC approach — the scenario definitions; our replication report records the results.
Upstream code	github.com/DEFINE-model/DEFINE_UK_1.1 — public but unlicensed; fetched at pinned commit `846081a` and run unmodified.
Our adapter	github.com/PolicyEngine/define-uk-model — run harness, validation record, scenario surface, and the clean-room reimplementation track.