Executive Summary
In this report we provide estimates of the size and value of the illicit drugs market as well as estimates of the economic and social cost of illicit drug use in Scotland for the year 2006. This work provides the first real attempt at both estimating the size of the market and the cost of illicit drug use in Scotland and has done so using only available data sources. Therefore, whilst this study is invaluable in providing an initial evidence base, the work also outlines the limitations of the methods employed as a result of using only available data sources and provides recommendations to aid the development of these methods and estimates in the future.
Prevalence of illicit drug use
Estimates of the number of both problem and recreational drug users using heroin, crack cocaine, methadone, powder cocaine, amphetamines, ecstasy, cannabis and benzodiazepines are needed to inform both the drug markets model and social and economic costs model.
The estimates for the number of problem drug users using all of the above drugs are derived from two data sources, the Drug Outcomes Research In Scotland ( DORIS) study and the 2006 national Prevalence Study (Hay et al, 2009). The estimates for the number of recreational drug users using all of the above drugs with the exception of heroin or crack cocaine are derived from two different data sources namely the 2006 Scottish Adolescent Lifestyle and Substance Use Survey ( SALSUS) and the 2006 Scottish Crime and Victimisation Survey ( SCVS). There are a number of assumptions and limitations associated with these estimates. As a result a sensitivity analysis is used to determine the effect such assumptions have on both the estimated size and value of the illicit drugs market and the total estimated economic and social cost of illicit drug use.
The prevalence of illicit drug use for problem and recreational drug users is estimated for all types of drugs. The estimates relating to problem drug use range from 6,135 problem drug users who use amphetamines to 50,077 problem drug users who use heroin. For recreational drug use our estimates range from 49,113 recreational drug users using benzodiazepines to 321,352 using cannabis.
Size and value of illicit drug market
The size of the illicit drugs market is estimated by combining the average amounts of drugs that problem and recreational drug users use in a year with the estimated prevalence of drug use for each drug type. The estimated size is then combined with price information for each drug type to estimate the total value of the illicit drugs market in Scotland. The DORIS study is utilised once again to examine the average amount and frequency of which each drug is used by problem drug users. There is not such a comprehensive dataset available for recreational drug users and so information on average quantity and frequency was gathered using a variety of sources including the SCVS and the Independent Drugs Monitoring Unit ( IDMU).
The Scottish Crime and Drug Enforcement Agency ( SCDEA) provided price information for all types of drug with the exception of benzodiazepines. This is combined with the estimated quantity of each drug used to give the estimated value of the drugs market. The total value of the illicit drugs market is estimated at around £1.4bn. Heroin holds the largest share of the market with 39% of the market, with cannabis holding a 19% share, the second largest. Problem drug users hold the largest percentage share of the total market (63%).
Given that each data source used was created for purposes other than those used for this study, there are a number of assumptions and limitations associated with using the data for this purpose. Once again a sensitivity analysis examines the effect such assumptions have on the total estimates.
Economic and social costs of illicit drug use
Cost consequences are identified using a similar approach to the previous Home Office studies (Godfrey et al, 2002; Gordon et al, 2006). Five cost areas are identified as: health, criminal justice, social care, costs to the economy and wider costs to society. Individual consequences are then identified for each area for both problem and recreational drug use. The total estimates for each area are calculated by combining information on the number of occurrences of each identified cost consequence with the unit price of each consequence.
In order to achieve this data from a large number of sources is employed. DORIS is used extensively to provide data on problem drug users while a larger number of separate data sources are used to provide data on recreational drug users, such as SMR01 for the health consequences.
The total economic and social cost of illicit drug use in Scotland is estimated at just under £3.5bn. Costs associated with problem drug use accounts for 96% of the total cost and this equates to just under £61,000 per problem drug user. Recreational drug use accounts for 4% of the total estimated cost equating to £134 per user.
As with the markets and prevalence estimates described above it is necessary to make a number of assumptions in order to produce estimates of the economic and social costs of illicit drug use in Scotland since we use only available data sources. Once more a sensitivity analysis is carried out to validate the model and determine the effect such assumptions have on the final estimate.
A number of recommendations are made in terms of improvements to the existing data available. Of note is the issue of average quantities used for each drug type. There is a dearth of data on average amounts of drugs consumed by recreational drug users. Although DORIS provides better information for problem drug users, the respondents in DORIS often gave their answer in monetary terms rather than weight. This problem is compounded by the issue of price varying by amount bought or possibly by type of drug user.
Estimating the economic and social costs of illicit drug use in Scotland is impeded by the lack of Scottish crime costs that can be used in conjunction with crimes carried out by problem drug users. Given that the costs of crime contribute largely to the total estimated cost, this is an important issue that would need to be addressed in order to improve on this study.