RESEARCH / VERSION 1.2 / 20 OCTOBER 2026
Conditional UK drug-market scenarios
A transparent calculation with explicit assumptions.
UK scenario = six-drug England subtotal × (UK population / England population) + cannabis England-and-Wales model × (UK population / England-and-Wales population).
| Case | England six drugs (£bn) | Cannabis E&W (£bn) | Calculated UK scenario (£bn) |
|---|---|---|---|
| Central / lower cannabis | 12.0 | 2.3 | 16.75 |
| Central / alternative cannabis | 12.0 | 3.6 | 18.21 |
Inputs: UK population 69,483,900; England 58,834,800; Wales 3,175,200, all mid-2025 estimates released 1 October 2026. Two decimals show arithmetic, not accuracy to £10 million. Equal per-resident spending is assumed outside observed geographies; mixed drug-data periods are not harmonised.
These two conditional illustrations do not establish a UK confidence interval, a 2026 forecast, observed receipts or proven bounds. The wider stress cases have been withdrawn from the current presentation pending clarification of the published aggregate margin. The published annexes describe the wastewater methodology, but the underlying NCA retail price and purity inputs and calculation code are not publicly available. The workbook and accompanying script reproduce CLA’s population extrapolations from published values; they do not reproduce or independently validate the underlying WAND consumption and valuation models.
Home Office inputs: section 2.4 · ONS population inputs: Table 1 · Download inputs and calculated values · Download reproducible Python calculation
Methodological update of 20 October 2026
We have removed the wider arithmetic stress range from the summary and current scenario table while seeking clarification of the aggregate uncertainty margin published in the Home Office’s proceeds-of-crime study. The source figures remain unchanged. CLA’s UK extrapolations remain conditional illustrations. We have clarified which calculations can be reproduced from public information; the available evidence still does not establish a complete, consistently measured UK total.