Licensing and regulation of the cannabis market in England and Wales: Towards a cost-benefit analysis

Pudney, Stephen and Bryan, Mark and DelBono, Emilia (2013): Licensing and regulation of the cannabis market in England and Wales: Towards a cost-benefit analysis. Published in: (15 September 2013): pp. 1-152.

Abstract

This study sets out the potential costs and benefits of a move to a licensed, taxed and regulated cannabis market in England and Wales. It identifies at least 17 sources of social cost/benefit and gives indicative estimates of annual net external benefit for 13 of them. We stress the important role of product regulation as a means of controlling the chemical properties of the cannabis product. Research in neuroscience has demonstrated the harmful effects of one cannabis constituent (THC) and the protective role of another (CBD). Given the strong upward trend in THC and downward trend in CBD in the illegal cannabis market, the possibility of product regulation is a potential advantage of a licensed and regulated system of supply. Three alternative scenarios are used, based on different assumptions about the responsiveness of demand to the policy change. We find that net benefits are likely to be positive and modest in size, except in the case of highly responsive demand (where, however, there is a great deal of uncertainty associated with the estimates). By far the largest effect is projected to be the net budgetary improvement for government, from new tax revenue and reduced policing and criminal justice costs.

• Item Type: MPRA Paper
• Language: English
• Keywords: cannabis, regulation, legalization
• Subjects: H - Public Economics > H2 - Taxation, Subsidies, and Revenue > H20 - General; I - Health, Education, and Welfare > I1 - Health > I18 - Government Policy ; Regulation ; Public Health; K - Law and Economics > K4 - Legal Procedure, the Legal System, and Illegal Behavior > K42 - Illegal Behavior and the Enforcement of Law

References

Advisory Council on the Misuse of Drugs (2008). Cannabis: Classification and Public Health. London: Home Office.

Allender, S., Balakrishnan, R., Scarborough, P., Webster, P. and Rayner, M. (2009). The burden of smoking-related ill health in the UK, Tobacco Control 18, 262-267.

Anderson, D. M. and Rees, D. I. (2011). Medical marijuana laws, traffic fatalities and alcohol consumption. Bonn: IZA Discussion Paper no. 6112.

APPGSH (2010). Inquiry into the effectiveness and cost-effectiveness of tobacco control. London: All-Party Parliamentary Group on Smoking and Health.

ASH (2011). ASH Briefing: UK Tobacco Control Policy and Expenditure. London: Action on Smoking and Health.

Atha, M. J. and Davis, S. T. (2011). Taxing the UK Cannabis Market (report commissioned by CLEAR). Independent Drug Monitoring Unit.

Bhattacharyya, S., Martin-Santos, M., Seal, M. L. and Mechelli, A. (2009). Modulation of mediotemporal and ventrostriatal function in humans by Delta9-tetrahydrocannabinol. A neural basis for the effects of cannabis sativa on learning and psychosis, Archives of General Psychiatry 66, 442-451.

Boydell, J., Van Os, J., Lambri, M., Castle, D., Allardyce, J. and Murray, R. M. (2003). Incidence of schizophrenia in south-east London between 1965 and 1997, British Journal of Psychiatry 182, 45-49.

Brand, S. and Price, R. (2000). The Economic and Social Costs of Crime. London: Home Office Research Study 217.

Branson, C., Duffy, B., Perry, C. and Wellings, D. (2012). Acceptable behaviour? Public opinion on behaviour change policy. London: Ipsos MORI.

Bray J. W., Zarkin, G. A., Ringwalt, C. and Qi. J. (2000). The relationship between Marijuana initiation and dropping out of high school, Health Economics 9, 9–18.

Bryan, M., DelBono, E. and Pudney, S. E. (2011). Drug-related crime. University of Essex: Working Paper.

Callum, C., Boyle, S. and Sandford, A. (2011). Estimating the cost of smoking to the NHS in England and the impact of declining prevalence. Health Economics, Policy and Law 6, 489-508.

Cameron, L. and Williams, J. (2001). Cannabis, alcohol and cigarettes – substitutes or complements?, Economic Record 77, 19-34.

Caulkins, J. P. (2010). Estimated Costs of Production for Legalized Cannabis, RAND working paper WR-764-RC.

Caulkins, J.P., Hawken, A., Kilmer, B., Kleiman, M. A. R. (2012). Marijuana Legalization. What Everyone Needs to Know. Oxford: Oxford University Press.

Caulkins, J.P., Kilmer, B., MacCoun, R. J., Pacula, R. L., Reuter, P. H. (2013). Design considerations for legalizing cannabis: lessons inspired by analysis of California’s Proposition 19, Addiction, 107, 865–871.

Chaloupka, F. J. and Laixuthai, A. (1997). Do Youth Substitute Alcohol and Marijuana? Some Econometric Evidence, Eastern Economic Journal, 23, 253–275.

Chaloupka, F. J., Pacula, R. L., Farrelly, M. C., Johnston, L. D., and O'Malley, P. M. (1999). Do higher cigarette prices encourage youth to use marijuana?, NBER Working Paper 6939.

Chatterji, P. (2006). Illicit drug use and educational attainment. Health Economics 15, 489–511.

Chivite-Matthews, N., Richardson, A., O’Shea, J., Becker, J., Owen, N., Roe, S. and Condon, J. (2005). Drug Misuse Declared: Findings from the 2003/04 British Crime Survey England and Wales. London: Home Office Statistical Bulletin 04/05.

Clements, K. and Daryal, M. (2005). The Economics of Marijuana Consumption. In: Selvanathan, E. and Selvanathan, S. (eds). The Demand for Alcohol, Tobacco, Marijuana and Other Evils. Ashgate, London.

Clements, K. W. and Zhao, X. (2005). Economic aspects of marijuana, University of Western Australia: Department of Economics Discussion Paper 05-28.

Cohen, M. A (1998). The Monetary Value of Saving a High Risk Youth, Journal of Quantitative Criminology 14, 5-33.

Cohen, M. A. and Piquero, A. R. (2009). New Evidence on the Monetary Value of Saving a High Risk Youth, Journal of Quantitative Criminology 25, 25-49.

Conti, G. (2010). Cognition, cannabis and wages. Mimeo, Department of Economics, University of Chicago.

Cooter, R. (1998). Expressive law and economics, Journal of Legal Studies 27, 585–607.

Criminal Records Bureau (2010). Annual Report and Accounts 2009/10. London: The Stationery Office, House of Commons document HC231.

Curran, H. V., Brignell, C., Fletcher, S., Middleton, P. and Henry, J. (2002). Cognitive and subjective dose-response effects of acute oral Delta9-tetrahydrocannabinol (THC) in infrequent cannabis users, Psychopharmacoloogy 164, 61-70.

Degenhardt, L., Hall, W. and Lynskey, M. (2002). Testing hypotheses about the relationship between cannabis use and psychosis, Drug and Alcohol Dependence 71, 37-48.

Department of Energy and Climate Change (2011). Quarterly Energy Prices, June 2011. http://www.decc.gov.uk/en/content/cms/statistics/publications/prices/prices.aspx.

Department for Environment, Food and Rural Affairs (2011), Farm Rents 2009 – England. http://www.defra.gov.uk/statistics/files/defra-stats-foodfarm-farmmanage-fbs-farmrents2009.pdf

Department for Transport (2010). Reported Road Casualties Great Britain: 2009 Annual Report. London: HMSO.

Department for Transport (2011). Transport Analysis Guidance Documents: Expert. http://www.ddft.gov.uk/webtag/documents/index.php, accessed 6 September 2011.

Department of Health (2002). Statutory Instrument 2002/3041: the tobacco products (manufacture, presentation and sale) (safety) regulations. London: HMSO.

Desimone, J. and Farrelly, M.C. (2003). Price and Enforcement Effects on Cocaine and Marijuana Demand, Economic Inquiry, 41, 98-115.

DiNardo, J. and Lemieux, T. (2001). Alcohol, Marijuana, and American Youth: The Unintended Effects of Government Regulation, Journal of Health Economics 20, 991–1010.

Dolan, K., Khoei, E. M., Brentari, C. and Stevens, A. (2007). Prison and drugs: A global review of incarceration, drug use and drug services. Oxford: The Beckley Foundation.

Duffy, M., Schaefer, N., Coomber, R., O’Connell, L. and Turnbull, P. J. (2008). Cannabis supply and young people ‘It’s a social thing’. York: Joseph Rowntree Foundation.

Ellgren, M., Spano, S. M. and Hurd, Y. L. (2006). Adolescent cannabis exposure alters opiate intake and opioid limbic neuronal populations in adult rats, Neuropsychopharmacology 32, 607–615.

Engberg J, Morral AR. 2006. Reducing substance use improves adolescents’ school attendance. Addiction 101: 1741–1751.

European Commission (2000). Communication from the Commission on the precautionary principle. Brussels: COM(2000) 1 final, 2nd February.

Farrelly, M. C., Bray, J. W., Zarkin, G. A., and Wendling, B. W. (2001). The joint demand for cigarettes and marijuana: evidence from the National Household Surveys on Drug Abuse, Journal of Health Economics 20, 51-68.

Fergusson DM, Horwood LJ. 1997. Early onset cannabis use and psychosocial adjustment in young adults. Addiction 92: 279–296.

Fischer, B., Jeffries, V., Hall, W., Room, R., Goldner, E. and Rehm, J. (2011). Lower risk cannabis use guidelines for Canada (LRCUG): A narrative review of evidence and recommendations, Canadian Journal of Public Health 102, 324-327.

Gill A and R Michaels. (1992). Does drug use lower wages? Industrial and Labor Relations Review 45, 419–434. Glaeser, E. L. and Schleifer, A. (2001). A reason for quantity regulation, American Economic Review Papers and Proceedings 91, 431-435.

Godfrey, C., Eaton, G., McDougall, C. and Culyer, A. (2002). The economic and social costs of class A drug use in England and Wales. London: Home Office Research Study 249.

Goldstein, P. (1985). The drugs/violence nexus: a tripartite conceptual framework, Journal of Drug Issues 15, 493-506.

Gordon, L., Tinsley, L. Godfrey, C. and Parrott, S. (2006). The economic and social costs of class A drug use in England and Wales 2003/4, in Measuring Different Aspects of Problem Drug Use: Methodological Developments, Home Office Online Report 16/06, pp. 41-45.

Gorman, W. M. (1980). A possible procedure for analysing quality differentials in the egg market, Review of Economic Studies 47, 843-856.

Gossop, M., Marsden, J., Stewart, D. (2001). NTORS after five years: changes in substance use, health and criminal behaviour during the five years intake. London: National Treatment Agency for Substance Misuse.

Gossop, M. (2006). Treating drug misuse problems: evidence of effectiveness. London: National Treatment Agency for Substance Misuse.

Grossman, M. (2004). Individual behaviours and substance use: the role of price, NBER Working Paper 10948.

Hardwick, S. and King, L. (2008). Home Office Cannabis Potency Study. London: Home Office.

Harries, R. (1999). The cost of criminal justice. London: Home Office Research Findings no. 103.

HMRC (2010). Measuring Tax Gaps 2010. London: HM Revue & Customs.

Hernandez, M. and Pudney, S. E. (2011). What you don't see can't hurt you? Panel data analysis and the dynamics of unobservable factors. University of Essex: ISER Working Paper no. 2011-13.

Hickman M., Vickerman P., Macleod J. (2007). Cannabis and schizophrenia: model projections of the impact of the rise in cannabis use on historical and future trends in schizophrenia in England and Wales, Addiction 102, 597–606.

House of Commons (2009). Health Committee – First Report Session 2009/10 Alcohol. London: Parliament.

Hough, M., Warburton, H., Few, B., May, T., Man, L.-H., Witton, J. and Turnbull, P. J. (2003). A growing market. The domestic cultivation of cannabis. York: The Joseph Rowntree Foundation.

Hughes, C. E. and Stevens, A. (2010). What can we learn from the Portuguese decriminalization of illicit drugs? British Journal of Criminology 50, 999-1022.

Hyggen, C. (2012). Does smoking cannabis affect work commitment? Addiction 107, 1309-1315.

Irons, D. E., McGue, M., Iacono, W. G. and Oetting, W. S. (2007). Mendelian randomization: a novel test of the gateway hypothesis and models of gene-environment interplay, Development and Psychopathology 19, 1181-1195.

Kaestner, R. (1991). The effects of illicit drug use on the wages of young adults, Journal of Labor Economics 9, 381–412.

Kaestner, R .1994. New estimates of the effects of marijuana and cocaine use on wages. Industrial and Labor Relations Review 47, 454–470.

Kahneman, D., and Tversky, A. (1979) Prospect theory: an analysis of decision under risk, Econometrica, 47, 263-291.

Kandel, D. B. (2002). Stages and Pathways of Drug Involvement, Cambridge: Cambridge University Press.

Kandel, D., Chen, K. and Gill, A. (1995). The impact of drug use on earnings: a life-span perspective, Social Forces 74, 243-270.

Kilmer, B., Caulkins, J.P., Pacula, R. L., MacCoun, R. J., Reuter, P. H. (2010). Altered State? Assessing how marijuana legalization in California could influence marijuana consumption and public budgets, RAND Occasional Paper. Santa Monica, CA: RAND Corporation.

Laibson, D. (1997). Golden Eggs and Hyperbolic Discounting. Quarterly Journal of Economics 112, 443–477.

Lancaster, K. J. (1966). A new approach to consumer theory. Journal of Political Economy 74, 132-157.

Laumon, B., Gadegbeku, B., Martin, J.-L. and Biecheler, M.-B. (2005). Cannabis intoxication and fatal road crashes in France: population based case-control study, British Medical Journal 331, 1371-1374.

McCaffrey, D. F., Pacula, R. L., Han, B. and Ellickson, P. (2010). Marijuana use and high school dropout: the influence of unobservables. Health Economics 19, 1281-1299.

MacCoun, R. J. and P. Reuter (2001). Drug War Heresies. Learning from Other Vices, Times and Places, Cambridge University Press, Cambridge.

MacCoun, R. J. (2010). Estimating the non-price effects of legalization on cannabis consumption, RAND Working Paper WR-767-RC.

McCrone, P., Dhanasiri, S., Patel, A., Knapp, M. and Lawton-Smith, S. (2008). Paying the price. The cost of mental health care in England to 2026. London, King’s Fund.

MacDonald, Z. and Pudney, S. E. (2000). Illicit drug use, unemployment, and occupational attainment, Journal of Health Economics 19, 1089–1115.

MacDonald, Z. and Pudney, S. E. (2001). Illicit drug use and labour market achievement, Applied Economics 33, 1655–1668.

MacDonald, Z., Tinsley, L., Collingwood, J., Jamieson, P., Pudney, S. E. (2005) Measuring the Harm from Illegal Drugs using the Drug Harm Index. London: Home Office Online Report 24/05.

MacDonald, Z., Collingwood, J., and Gordon, L. (2006) Measuring the Harm from Illegal Drugs using the Drug Harm Index – an Update. London: Home Office Online Report 08/06.

McManus, S., Meltzer, H., Brugha, T., Bebbington, P. and Jenkins, R. (2009). Adult Psychiatric Morbidity in England, 2007. London: NHS Information Centre for Health and Social Care.

Madden, G. J., Petry, N. M., Bickel, W. K., Badger, G. J. (1997). Impulsive and self-control choices in opiate-dependent patients and non-drug-using control participants: Drug and monetary rewards. Experimental and Clinical Psychopharmacology 5, 256–262.

Markowitz, S. and Tauras, J. (2006). Even for teenagers, money does not grow on trees: teenage substance use and budget constraints, NBER Working Paper 12300.

May, T., Warburton, H., Turnbull, P. J. and Hough, M. (2002). Times they are a-changing. Policing of cannabis. York: Joseph Rowntree Foundation.

May, T., Duffy, M., Warburton, H. and Hough, M. (2002). Policing cannabis as a class C drug An arresting change?. York: Joseph Rowntree Foundation.

May, T., Duffy, M., Few, B. and Hough, M. (2005). Understanding Drug Selling in Communities. Insider or Outsider Trading? York: Joseph Rowntree Foundation.

Metcalf, H., Anderson, T. and Rolfe, H. (2001). Barriers to Employment for Offenders and Ex-Offenders. London: Department for Work and Pensions.

Mills, H., Silvestri, A. and Grimshaw, R. (2010). Police Expenditure 1999-2009. London: Centre for Crime and Justice. Ministry of Justice (2010a). Sentencing Statistics: England and Wales 2009. London: Ministry of Justice Statistics Bulletin.

Ministry of Justice (2010b). Ministry of Justice Resource Accounts 2009-10. London: The Stationery Office, House of Commons document HC194.

Miron, J. A. (2003). The effect of drug prohibition on drug prices: evidence from the markets for cocaine and heroin, Review of Economics and Statistics 85, 522-530.

Moore, T. H. M., Zammit, S., Lingford-Hughes, A., Barnes, T. R. E., Jones, P. B., Burke, M. and Lewis, G. (2007). Cannabis use and risk of psychotic or affective mental health outcomes: a systematic review, The Lancet 370, 319-328.

Morgan, C. J. and Curran, H. V. (2008). Effects of cannabidiol on schizophrenia-like symptoms in people who use cannabis, British Journal of Psychiatry 192, 306-307.

Morgan, C. J., Freeman, T. P., Schafer, G. L. and Curran, H. V. (2010). Cannabidiol attenuates the appetitive effects of Delta 9-tetrahydrocannabinol in humans smoking their chosen cannabis, Neuropsychopharmacology. 35, 1879-1885.

Morgan, C. J., Schafer, G. L., Freeman, T. P. and Curran, H. V. (2010). Impact of cannabidiol on the acute memory and psychotomimetic effects of smoked cannabis: naturalistic study, British Journal of Psychiatry 197, 285-290.

Murray, R. (2007). Teenage schizophrenia is the issue, not legality. The Independent 18 March 2007.

National Audit Office (2006). Department for Constitutional Affairs. Fines Collection. London: The Stationery Office. National Audit Office (2008). National Probation Service. The supervision of community orders in England and Wales. London: The Stationery Office.

National Audit Office (2010). Tackling Problem Drug Use. London: The Stationery Office, House of Commons document HC297.

National Centre for Social Research (2011). Smoking, Drinking and Drug Use by Young People in England in 2010. London: National Centre for Social Research.

NDTMS (2011). Statistics from the National Drug Treatment Monitoring System 1st April 2009-31st March 2010. University of Manchester: National Drug Evidence Centre.

NICE (2003). Review of Clinical Guideline (CG8) – Multiple sclerosis: national clinical guideline for diagnosis and management in primary and secondary care. National Institute for Health and Clinical Excellence, Centre for Clinical Practice.

NTA (2006). Improving Services for Substance Misuse. London: Commission for Healthcare Audit and Inspection.

North, P. (2010). Report of the review of drink and drug driving law. London: Department for Transport.

Nutt, D. (2008). Equasy – an overlooked addiction with implications for the current debate on drug harms. Journal of Psychopharmacology 23, 3–5.

Pacula, R. L. (1998). Does increasing the beer tax reduce marijuana consumption?, Journal of Health Economics, 17(5), 557-585.

Pacula, R. L. (2010). Examining the impact of marijuana legalization on marijuana consumption: insights from the economics literature. RAND Corporation Santa Monica: RAND Working Paper WR-770-RC.

Pacula, R. L., Grossman, M., Chaloupka, F. J., O’Malley, P. M., Johnston, L. D. and Farrelly M. C. (2001). Marijuana and youth, in Gruber, J. (Eds), Risky Behavior Among Youth: An Economic Analysis, Chicago: University of Chicago Press.

Pacula, R. L., Ringel, J. and Ross, K. E. (2003). Does marijuana use impair human capital formation? NBER Working Paper 9963.

Pager, D. (2003). The mark of a criminal record, American Journal of Sociology 108, 937-975.

Panlilio, L. V., Solinas, M., Matthews, S. A. and Goldberg, S. R. (2006). Previous exposure to THC alters the reinforcing efficacy and anxiety-related effects of cocaine in rats, Neuropsychopharmacology 32, 646–657.

Pearl, J. (2000). Causality: Models, Reasoning and Inference. Cambridge: Cambridge University Press.

Phillips, C. and Bloodworth, A. (2009). Cost of Smoking to the NHS in Wales, ASH Wales/ BHF Cymru.

Potter, D. J., Clark, P. and Brown, M. B. (2008). Potency of Delta9-THC and other cannabinoids in cannabis in England in 2005: implications for psychoactivity and pharmacology, Journal of Forensic Science 53, 90-94.

Pudney, S. E. (1981). Instrumental Variable Estimation of a Characteristics Model of Demand, Review of Economic Studies 48, 417-433.

Pudney, S. E. (2004). Keeping off the grass? An econometric model of cannabis consumption in Britain, Journal of Applied Econometrics 19, 435-453.

Pudney, S. E. (2003). The road to ruin? Sequences of initiation to drugs and crime in Britain, Economic Journal, 113, C182-C198.

Pudney, S.E., Badillo, C., Bryan, M., Burton, J., Conti, G. and Iacovou, M. (2006). Estimating the Size of the UK Illicit Drugs Market, in Measuring Different Aspects of Problem Drug Use: Methodological Developments, Home Office Online Report 16/06, pp. 46-120.

Pudney, S. E. (2010). Drugs policy: what should we do about cannabis? Economic Policy 25, 165-211.

Register, C. A. and Williams, D. R. (1992). Labor market effects of marijuana and cocaine use among young men, Industrial and Labor Relations Review, 45, 435-451.

Register, C. A., Williams, D. R. and Grimes, P. W. (2001). Adolescent drug use and educational attainment, Education Economics 9, 1–18.

Roebuck, M. C. , French, M. T. and Dennis, M. L. (2004). Adolescent marijuana use and school attendance, Economics of Education Review 23, 133–141.

Rolles, S. (2009). After the War on Drugs: Blueprint for Regulation. Bristol: Transform Drug Policy Foundation.

Saffer, H. and Chaloupka, F. (1999). The Demand for Illicit Drugs, Economic Inquiry, 37, 401-411.

Saffer, H. and F. J. Chaloupka (2000). The effect of tobacco advertising bans on tobacco consumption, Journal of Health Economics 19, 1117–1137.

Saffer, H. and D. Dave (2002). Alcohol consumption and alcohol advertising bans, Applied Economics 34, 1325–1334.

Shanahan, M. and Ritter, A. (2011). Cost benefit analysis of two policy options for cannabis: status quo and legalisation. National Drug and Alcohol Research Centre: mimeo.

Shanahan, M. and Ritter, A. (2013). Confronting the challenges of conducting a CBA of cannabis policies, Drugs: Education, Prevention and Policy, forthcoming.

Shrier, I. and Platt, R. W. (2008). Reducing bias through directed acyclic graphs, BMC Medical research Methodology 8: 70.

Solinas, M., Panlilio, L. V. and Goldberg, S. R. (2004). Exposure to Delta9-tetrahydrocannabinol (THC) increases subsequent heroin taking but not heroin's reinforcing efficacy: a self-administration study in rats, Neuropsychopharmacology 29, 646–657.

Suff, R. (2005). Checking out the activities of the Criminal Records Bureau, IRS Employment Review 483, 42-48.

Toonen M., Ribo, S. and Thissen, J.(2006). Yield of illicit indoor cannabis cultivation in the Netherlands, Journal of Forensic Sciences 51, 1050–1054.

Tunbridge, R. J., Keigan, M. and James, F. (2001). The incidence of drugs and alcohol in road accident fatalities. Crowthorne: TRL Report 495.

UK Focal Point (2001), Annual Report on the United Kingdom Drug Situation 2001 http://www.emcdda.europa.eu/html.cfm/index34779EN.html

UK Focal Point (2005), National Report to the EMCDDA by the Reitox National Focal Point: New developments, trends and in-depth information on selected issues http://www.nwph.net/ukfocalpoint/writedir/95f02005%20FP%20Annual%20Report.pdf

UK Focal Point (2010), United Kingdom Drug Situation (2010 edition). Annual Report to the EMCDDA. http://www.nwph.net/ukfocalpoint/writedir/fcf022035%20FOCAL%20POINT%20REPORT%202010%20A4.pdf

Uva, W.-F. and Richards, S. (2003). New York greenhouse business summary and financial analysis, derived from 2001 business records. Cornell University: Department of Applied Economics and Management Extension Bulletin EB 2003-12.

Van Ours, J. C. (2007a). Cannabis use when it’s legal, Addictive Behaviors 32, 1441–50.

Van Ours, J. C. (2007b). The effects of cannabis use on wages of prime-age males, Oxford Bulletin of Economics and Statistics 69, 619-634.

Van Ours, J. C. and Williams, J. (2007). Cannabis prices and dynamics of cannabis use, Journal of Health Economics, 26, 578-596.

Van Ours, J. C., and Williams, J. (2009). Why parents worry: initiation into cannabis use by youth and their educational attainment, Health Economics 29, 132-142.

Wilkins, C., and Sweetsur, P. (2006). Exploring the structure of the illegal market for cannabis in New Zealand. De Economist 154, 547-562.

Williams, J. (2004). The effects of price and policy on marijuana use: what can be learned from the Australian experience? Health Economics 13, 123-137.

Williams, J., Pacula, R. L., Chaloupka, F. J. and Wechsler, H. (2004). Alcohol and marijuana use among college students: economic complements or substitutes? Health Economics, 13, 825–843.

Yamada, T., Kendix, M. and Yamada, T. (1996). The impact of alcohol consumption and marijuana use on high school graduation. Health Economics 5, 77–92.

Yörük, B. K. and Yörük, C. E. (2011). The impact of minimum legal drinking age on alcohol consumption, smoking, and marijuana use: evidence from a regression discontinuity design using exact date of birth, Journal of Health Economics 30, 740-752.

Zhao, X. and Harris, M. N. (2004). Demand for marijuana, alcohol and tobacco: participation, levels of consumption and cross-equation correlations, Economic Record, 80, 394–410.