| 1 | Home Office (2026). The proceeds of crime in England and Wales 2023 to 2024. Published 15 September. Section 2.4, Tables 1 and 2; geographical and timing qualifications; alternative cannabis model. | Combined valuation / cannabis model | Drug-supply valuation, mixed England / England-and-Wales coverage
Six-drug equivalent retail value, England 2024–25 |
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| 2 | Home Office (2026). Wastewater Analysis Estimating drug consumption. Published 13 April; updated 8 October. Table 1 and Annexes A and B. Publication history is linked from the report. | Consumption-based valuation | Six-drug equivalent retail value, England 2024–25 |
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| 3 | Home Office (2020). Review of drugs Evidence pack, supporting Dame Carol Black’s phase one review. Slides 61 to 64, particularly the explicit England and Wales and 2016/17 labels. | Historical retail estimate and separate harm estimate | England and Wales retail market, 2016/17
Social and economic harms, England 2017/18 |
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| 4 | Office for National Statistics (2026). Consumer trends, series MNC2, 02.3 Narcotics CP NSA £m. Annual 2024 and 2025 observations, release dated 30 September 2026. Current prices; not a GDP value-added series. | National accounts estimate | ONS narcotics expenditure, 2025 — September 2026 vintage |
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| 5 | Pudney S, Badillo C, Bryan M, Burton J, Conti G and Iacovou M (2006). Estimating the size of the UK illicit drug market. Chapter 4 in Measuring different aspects of problem drug use, Home Office Online Report 16/06. Printed pages 46–48 and the discussion of baseline limitations. | Historical retail estimate | UK retail market, 2003/04 |
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| 6 | Bramley-Harker E (2001). Sizing the UK market for illicit drugs. Home Office RDS Occasional Paper 74. Original report catalogue and abstract; the monetary estimate is also reported in source 5. | Historical estimate traced through later study and catalogue | Report bibliography; not a separate structured estimate in this release |
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| 7 | Mills H, Skodbo S and Blyth P (2013). Understanding organised crime Estimating the scale and the social and economic costs. Home Office Research Report 73. Drugs supply section and Annex 2; 2010 market estimate. | Historical market model | Report bibliography; not a separate structured estimate in this release |
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| 8 | Home Office (2019). Understanding organised crime 2015/16, second edition. Section 2.1, especially 2.1.1 Scale and 2.1.2 Social and economic cost. Distinguishes the £4.5bn market from the £20bn cost estimate. | Historical model drawing on national accounts | Report bibliography; not a separate structured estimate in this release |
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| 9 | Casey J, Hay G, Godfrey C and Parrott S (2009). Assessing the scale and impact of illicit drug markets in Scotland. Scottish Government Social Research. Executive summary and market model; estimates refer to 2006. | Scotland-specific historical market model | Report bibliography; not a separate structured estimate in this release |
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| 10 | Snowdon C (2018). Joint Venture Estimating the size and potential of the UK cannabis market. Institute of Economic Affairs. Publisher summary of 29 June, including 2016/17 quantity and retail-value calculations. | Cannabis model | Report bibliography; not a separate structured estimate in this release |
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| 11 | Parey M and Rasul I (2021). Measuring the Market Size for Cannabis A New Approach Using Forensic Economics. Economica 88, 297–338. DOI 10.1111/ecca.12354. Final publication uses 2008–09 data. | Cannabis research method | Report bibliography; not a separate structured estimate in this release |
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| 12 | Atha MJ and Davis ST (2011). Taxing the UK Cannabis Market. Independent Drug Monitoring Unit, 26 August. Table 11 and section 4.4.1, page 10; sections 10.1 and 10.6, pages 24–25. Upper values differ between the body and summary. BMJ response attachment, not a BMJ research article. | Cannabis model; response attachment, not journal research article | Report bibliography; not a separate structured estimate in this release |
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| 13 | EUDA / EMCDDA (2022). Cocaine retail markets Multiple indicators suggest continued growth and diversification. National market size estimates section; reports NCA’s 2019 Great Britain assessment and the mixed-methods basis. | EUDA account of NCA cocaine assessment | Report bibliography; not a separate structured estimate in this release |
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| 14 | House of Commons Home Affairs Committee (2022). Oral evidence on Drugs, HC 198, 29 June. Steve Rodhouse, National Crime Agency, on cocaine valuation and consumption. Evidence record 10516, question 267. | Direct NCA parliamentary testimony; related to source 13 | Report bibliography; not a separate structured estimate in this release |
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| 15 | UK Parliament (2025). Written question 71709 on illegal-drug market values. Answer by Sarah Jones, 11 September, referring back to the Black review evidence pack. | Repetition of source 3 | Home Office confirms the existing estimate, 2025 |
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| 16 | Office for National Statistics (2025). Drug misuse in England and Wales Year ending March 2025. Released 11 December. Main points, frequency of use, and data sources and quality. | Background use survey | Report bibliography; not a separate structured estimate in this release |
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| 17 | Department of Health and Social Care and UK Health Security Agency (2025). Estimates of opiate and crack use in England 2022 to 2023 Main points and methodology. National estimate and methodology-change warning. | Prevalence / methods context | Report bibliography; not a separate structured estimate in this release |
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| 18 | Public Health Scotland (2026). Estimated prevalence of opioid dependence in Scotland 2014/15 to 2023/24. Main points, incorporating the correction of 23 June 2026. | Scotland prevalence / methods context | Report bibliography; not a separate structured estimate in this release |
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| 19 | National Crime Agency (2026). National Strategic Assessment 2026 Harm to individuals. Illicit drugs assessment concerning developments in 2025. | Qualitative threat assessment | NCA’s 2026 assessment: market context |
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| 20 | Home Office (2026). Seizures of drugs in England and Wales Financial year ending 2025. Interpretation warnings and sections 2 and 3 on powder-cocaine incidents and quantities. | Seizure context; not market size | Report bibliography; not a separate structured estimate in this release |
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| 21 | Department of Justice Northern Ireland (2026). Relentless efforts lead to results against organised crime Long. Published 20 July, reporting on the Organised Crime Task Force 2024/25 annual report. Seizure valuations are not total-market estimates. | Seizure context; not market size | Report bibliography; not a separate structured estimate in this release |
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| 22 | RAND Europe (2016). Internet-facilitated drugs trade An analysis of the size scope and the role of the Netherlands. English summary, particularly the discussion of wholesale transactions on page 6. | Distribution-channel analysis; not additive market | Report bibliography; not a separate structured estimate in this release |
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| 23 | EMCDDA and Europol (2024). EU Drug Markets Analysis Key insights for policy and practice. Aggregate estimate refers to 2021 EU retail expenditure. | EU context; not UK estimate | Report bibliography; not a separate structured estimate in this release |
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| 24 | UNODC (2026). World Drug Report 2026 data portal. Trends in coca cultivation and cocaine manufacture; estimated potential manufacture in 2024. | Global supply context; not UK estimate | Report bibliography; not a separate structured estimate in this release |
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| 25 | Office for National Statistics (2026). Population estimates for the UK England Wales Scotland and Northern Ireland Mid-2025. Released 1 October. Table 1; all population inputs use the same publication vintage. | Population input for CLA scenario | Report bibliography; not a separate structured estimate in this release |
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| 26 | McCall AK and colleagues (2016). Critical review on the stability of illicit drugs in sewers and wastewater samples. Water Research 88, 933–947. DOI 10.1016/j.watres.2015.10.040. University of Copenhagen abstract and bibliographic record. | Biomarker-stability methods check | Report bibliography; not a separate structured estimate in this release |
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| 27 | HM Government (2017). 2017 Drug Strategy. Introduction, page 6 of the PDF, identifying £10.7bn as social and economic cost in England and Wales. | Social costs; not turnover | Report bibliography; not a separate structured estimate in this release |
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| 28 | Office for National Statistics (2016). National Accounts articles Changes to National Accounts Blue Book 2016 Improvements to household expenditure estimates. Released 30 June; development programme includes narcotics sources and methods. | National accounts methods | Report bibliography; not a separate structured estimate in this release |
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| 29 | Home Office (2026). Wastewater analysis Estimating drug consumption 2021 to 2026. Published 14 October. Sections 1.3 and 2, Table 1 and its footnotes; trends at 16 consistently monitored English sites, not a national monetary valuation. Accessed 15 October 2026. | Consumption trend; no new monetary estimate | Wastewater trends at 16 English sites, 2021–26 |
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