Evidence based drug policy?…..Not yet in Italy

Carla RossiIllicit Drug Market Institute

eConsiglio Italiano per le Scienze Sociali

12 ottobre 2010, Università Commerciale Luigi Bocconi, Milano

Consiglio italianoper le Scienze Sociali

After the white books CSS and IDM…

• EU projects:• New methodological tools for policy and

programme evaluation (February 2011-February 2013)

• Study on the further analysis of the EU illicit drugs market and responses to it – responding to future challenges (September 2011-November 2012)

Evidences

• Several new data bases have been acquired and new methods of analysis have been developed in the framework of the two EU projects.

• These new tools allow assessment and evaluation of drug policies and interventions.

• Various different approaches have been compared: Italian, Portuguese, Czech, Swedish, Dutch.

• Some “best practices” can be identified.

The size of the Italian market• First the size of the hidden population of street

dealers has been estimated on the basis of two different data bases: the data base of the persons registered for dealing and the data base of the persons incarcerated for drug dealing (in both cases the individuals breached art. 73 of the drug law). The reference to the various substances was possible using the information on police operations and seizures provided by the Directorate of Anti Drug Services (DCSA).

• From the two data bases quite similar estimates have been obtained.

Estimates of the size of the dealers populationyear Zero-truncated Model 95%CI

2005

Chao 351890 339168-365159Chao (covariates) 352129 339379-365428Zelterman 353566 340367-367351Zelterman (covariates) 353806 340579-367621Negative Binomial (covariates) 305418 295589-315246

2006

Chao 351780 339717-364338Chao (covariates) 353208 340973-365950Zelterman 353530 340988-366603Zelterman (covariates) 354962 342249-368220Negative Binomial (covariates) 304491 295211-313770

2007

Chao 372523 360141-385396Chao (covariates) 372613 360222-385496Zelterman 374446 361570-387851Zelterman (covariates) 374541 361655-387957Negative Binomial (covariates) 319456 310129-328781

2008

Chao 384885 372499-397748Chao (covariates) 385940 373437-398928Zelterman 386584 373706-399976Zelterman (covariates) 387648 374652-401166Negative Binomial (covariates) 339503 329725-349280

2009

Chao 385365 372499-397748Chao (covariates) 387056 373599-401068Zelterman 386684 372953-400994Zelterman (covariates) 388372 374436-402902Negative Binomial (covariates) 349281 338218-360344

Estimates from the prison population data set

Zelterman estimate for 2007 from the other data set was: 374,541 and Chao was: 372,613

For 2008 Zelterman was: 387,648 and Chao was: 385,940

Estimates from prison data set are inside the confidence intervals of the estimates from the other data set.

Adjustments

• Part time dealing (from literature 6 months a year);

• Different capture rates per substance (seizure data and literature);

• Dealer population not at risk for only cannabis dealing (from literature).

Consumer population estimation

SubstanceEstimated active dealers

Ratio (Reuter)

Ratio (Bouchard & Tremblay) Estimated

active consumers (Reuter)

Estimated active consumers (Bouchard & Tremblay)

Average

Cannabis 143,700 4032 5,748,000 4,598,400 5,173,200

Cocaine 56,600 2528 1,415,000 1584,800 1,499,900

Opiates 47,000 1516 705,000 752,000 728,500

Total247,300

These estimates are affected by double counting for poly-use and poly-dealing

Market estimation (supply side)

SubstanceEstimated active dealers

Median number of doses sold per week of activity

Sample size dose

Mean price per dose

Sample size price

Total amount (billion euro)

Cannabis 143,700 10091 10 351

7.472

Cocaine 56,600 50164 75 387 11.037

Opiates 47,000 50156 35 504 4.277

Total 247,300 22.786

Market estimation (demand side)

SubstanceEstimated active consumers

Average number of doses per month per person

Mean price per dose

Total amount (billion euro)

Cannabis 5,173,200 10 10 6.208

Cocaine 1,499,907 9 75 12.149

Opiates 728,500 15 35 4.590

Total 7,401,607 22.947

Estimation of the cannabis market from other sources (Transcrime)

• Transcrime estimates of consumers: 7,280,000• 50% occasional, • 21% regular, • 29% intensive• Average number of doses per month=12• Price per dose (average)=10 euro• Estimate of the cannabis market=

7,280,000*10*12 *12 billion euro=10.483.

• Estimates of consumers: 5,173,200• 55% occasional (50%)• 23% regular (21%)• 22% intensive (29%)• Average grams consumed per year• Occasional: 7.9• Regular: 107.4• Intensive: 352.3• Total value of the market=

5,173,200(0.55*7.9+0.23*107.4+352.3*0.22)*10=5.512 billion euro (6.656 billion euro)

Estimation of the cannabis market from other sources (Study on the further analysis of the EU illicit drugs market and responses to it – responding to future challenges)

Interception rate (Italy 2011)

Interception rate for cannabis= 19.32% (with plants)Intercepton rate for cannabis= 5.35% (without plants)

Seizures 2011

SubstanceAmount (Kgs)

unit price wholesale (euro)

Total (million euro)

value retail market (million euro)

Ratio(value sized/value of the retail market)

cocaine 6,346.3 39,000 247,505.700 12,149,000 0.020heroin 810 24,700 20,007 4,509,000 0.004marjuana 10,907.88 1,360 14,834.717 hashish 20,257.57 2,200 44,566.654 Plants (in Kgs of product) 1,008,22.8 1,360 137,119.008 6,208,000 0.032

Total 464,033.079 22,866,000 0.028

Age at onset of cannabis use and problem drug use

• It is often mentioned that starting earlier consuming drugs (for about 75% the first drug used is cannabis) is a risk factor for the use of more harmful substances.

• We had the possibility to analyse two different sets of data: the data from the survey among PDUs and the web-survey on cannabis users (mostly non problematic) and to compare the proportions of first use of cannabis before 15 years of age for Italy and Portugal.

CAST scores for the web-survey (7=moderate dep; 12=severe dep)

Occasional Regular Intensive

Czech Republic

Mean 4.1 6.3 9.0

Median 3.0 6.0 8.0

Italy Mean 4.2 6.7 7.9

Median 4.0 6.0 8.0

Portugal Mean 3.8 6.5 9.6

Median 4.0 6.0 9.0

Median 4.0 7.0 9.0

ODD’S RATIO Italy   Males           <15 15≤ TotalWeb 180 633 813Survey 202 221 423Total 382 854 1236

   

  OR=3.2143 p=0.00000

   

   

   Italy   Females           <15 15≤ TotalWeb 47 189 236Survey 32 34 66Total 79 223 302

   

  OR=3.7847 p=0.00052       

Portugal   Males  

       

  <15 15≤ Total

Web 20 77 97

Survey 107 139 246

Total 127 216 343

   

  OR=2.9637 p=0.0011

   

   

   

Portugal   Females  

       

  <15 15≤ Total

Web 7 47 54

Survey 20 25 45

Total 27 72 99

   

  OR=5.3714 p=0.0055

Remarks

• Law enforcement interventions seems to produce quite negligible damages to the drug traffickers. Hsi is also confirmed by the stable or decreasing behaviour of the prices.

• New and new substances are offered on the market. These substances are not illicit until their

• Effects are not assessed. In the first months of 2012 more than 100 new substnes have been detected.

• What about the outcomes of less repressive policies such as the Portuguese one? Is it true that this approach might push more young people to star consuming?

Incidence indicators

• Indicators based on incidence are the most appropriate for evaluation of policies and interventions.

• It is generally recognised that early use of cannabis is associated with higher risk of harmful use of other substances.

• Thus it is important to estimate incidence of cannabis use among teenagers. This can be obtained by combining various sources of information.

Estimating incidence from prevalence

• Denote by g(a) the density function and G(a) the (cumulative) distribution function of the age at first use of a specific substance.

• Denote by P(a,t) the prevalence of users aged a at time t.

• The expected number of subjects of the population P(a,t) who started using that substance at time t is denoted by I(a,t).

Estimating incidence from prevalence

• I(a,t) can be estimated by multiplying the prevalence P(a,t) by the probability of onset at age a g(a) given that the age at onset is not higher than a G(a):

)(

)(),(),(

aG

agtaPtaI

P(a,t), G(a), g(a) and I(a,t) among teenagers in Italy (2012)

Age

g(a): source web-survey on cannabis

use

G(a)P(a,t): source

SPS and demographic

data I(a,t)

15 0.22 0.438 25,983 13,133

16 0.21 0.652 59,023 19,415

17 0.14 0.793 84,435 15,020

18 0.10 0.890 101,725 11,109

19 0.04 0.931 110,712 4,873

Total 381,878 63,550

About incidence

• Overall the incident cases among teenagers aged 15-19 are about 17% of the prevalent cases.

• I(15,t)/P(15,t)>0.5 is the highest value and corresponds to the mode of the onset age distribution.

• The minimum value of the ratio is for a=19:• I(19,t)/P(19,t)<0.05.

Example: estimate for Portugal

Age

P(a,t): source estimates from ESPAD Study

g(a): source web-survey on cannabis use G(a) I(a,t)

15 4,800 0.11 0.29 1,821

16 9,200 0.27 0.56 4,436

17 11,600 0.16 0.72 2,578

18 15,700 0.14 0.86 2,556

Total 41,300 11,390

Remarks• In the case of Portugal the ratio

incidence/prevalence for ages 15-18 is 0.28.• If ages 15-18 are considered for Italy, the ratio

is 0.22.• The difference is due to the onset age

distributions.• In Italy the proportion of those who start

before 15 is higher than in Portugal (22% versus 21% for males and 20% versus 13% for females).

White books

• AA.VV., “Act upon the market to fight the illicit drug industry”, IDM editions, 2010.

• Rey G.A., Rossi C., Zuliani A., “Il mercato delle droghe: dimensione, protagonisti, politiche”, Marsilio Editori, Venezia, 2011.

Thank you very much

•Comments, questions?