- Introduction
- U.S. Studies
- International Studies
"The
available evidence suggests that removal of the prohibition against
possession itself (decriminalization) does not increase cannabis use.
... This prohibition inflicts harms directly and is costly. Unless it
can be shown that the removal of criminal penalties will increase use of
other harmful drugs, ... it is difficult to see what society gains."
- Evaluating alternative cannabis regimes.
British Journal of Psychiatry. February 2001.
Introduction
Findings
from dozens of government-commissioned and academic studies published
over the past 25 years overwhelmingly affirm that liberalizing marijuana
penalties
does not lead to an increase in marijuana consumption or affect adolescent attitudes toward drug use.
Since
1973, 13 state legislatures -- Alaska, California, Colorado, Maine,
Massachusetts, Minnesota, Mississippi, Nebraska, Nevada, New York, North
Carolina, Ohio and Oregon -- have enacted versions of marijuana
decriminalization. In each of these states, marijuana users no longer
face jail time (nor in most cases, arrest or criminal records) for the
possession or use of small amounts of marijuana. Internationally, many
states and nations have enacted similar policies.
The following
studies examine these decriminalization policies and their impact on
marijuana use. The studies' conclusions are listed chronologically.
U.S. Studies
"In
sum, there is little evidence that decriminalization of marijuana use
necessarily leads to a substantial increase in marijuana use." - National Academy of Sciences, Institute of Medicine (IOM). 1999.
Marijuana and Medicine: Assessing the Science Base. National Academy Press: Washington, D.C., 102.
"The
Law Revision Commission has examined laws from other states that have
reduced penalties for small amounts of marijuana and the impact of those
laws in those states. ... Studies of [those] states found (1) expenses
for arrest and prosecution of marijuana possession offenses were
significantly reduced, (2) any increase in the use of marijuana in those
states was less that increased use in those states that did not
decrease their penalties and the largest proportionate increase occurred
in those states with the most severe penalties, and (3)
reducing
the penalties for marijuana has virtually no effect on either choice or
frequency of the use of alcohol or illegal 'harder' drugs such as
cocaine." - Connecticut Law Review Commission. 1997.
Drug Policy in Connecticut and Strategy Options: Report to the Judiciary Committee of the Connecticut General Assembly. State Capitol: Hartford.
"There
is no strong evidence that decriminalization affects either the choice
or frequency of use of drugs, either legal (alcohol) or illegal
(marijuana and cocaine)." - C. Thies and C. Register. 1993.
Decriminalization of Marijuana and the Demand for Alcohol, Marijuana and Cocaine. The Social Sciences Journal 30: 385-399.
"In
contrast with marijuana use, rates of other illicit drug use among ER
[emergency room] patients were substantially higher in states that did
not decriminalize marijuana use. The lack of decriminalization might
have encouraged greater use of drugs that are even more dangerous than
marijuana." - K. Model. 1993. The effect of marijuana decriminalization on hospital emergency room episodes: 1975-1978.
Journal of the American Statistical Association
88: 737-747, as cited by the National Academy of Sciences, Institute of
Medicine in Marijuana and Medicine: Assessing the Science Base. [6]
"The available evidence indicates that the decriminalization of marijuana possession had little or no impact on rates of use.
Although rates of marijuana use increased in those U.S. states [that]
reduced maximum penalties for possession to a fine, the prevalence of
use increased at similar or higher rates in those states [that] retained
more severe penalties. There were also no discernible impacts on the
health care systems.
On the other hand, the so-called 'decriminalization' measures did result in substantial savings in the criminal justice system." - E. Single. 1989. The Impact of Marijuana Decriminalization: An Update.
Journal of Public Health 10: 456-466.
"Overall,
the preponderance of the evidence which we have gathered and examined
points to the conclusion that decriminalization has had virtually no
effect either on the marijuana use or on related attitudes and beliefs
about marijuana use among American young people. The data show
no evidence of any increase, relative to the control states, in the
proportion of the age group who ever tried marijuana.
In fact,
both groups of experimental states showed a small, cumulative net
decline in annual prevalence after decriminalization." - L. Johnson et al. 1981. Marijuana Decriminalization: The Impact on Youth 1975-1980.
Monitoring the Future, Occasional Paper Series, paper 13, Institute for Social Research, University of Michigan: Ann Arbor.
"Consumption
appears to be unaffected, or affected only minimally by
decriminalization, and most people believe that it has had little
impact. Further, decriminalization has proven to be administratively and economically advantageous for state law enforcement efforts."
- D. Maloff. 1981.
Review of the effects of decriminalization of marijuana. Contemporary Drug Problems Fall: 307-322.
"Levels
of use tended to be higher in the decriminalization states both before
and after the changes in law. [S]tates which moderated penalties after
1974 (essentially a group of decriminalization states) did indeed
experience an increase in rates of marijuana use, among both adolescents
(age 12-17) and adults (18 or older).
However, the increase in
marijuana use was even greater in other states and the largest
proportionate increase occurred in those states with the most severe
penalties." - W. Saveland and D. Bray. 1980.
American Trends in Cannabis Use Among States with Different Changing Legal Regimes.
Bureau of Tobacco Control and Biometrics, Health and Welfare: Ottawa,
as cited by E. Single in The Impact of Marijuana Decriminalization: an
Update.
"The reduction in penalties for possession of
marijuana for personal use does not appear to have been a factor in
people's decision to use or not use the drug." - California State Office of Narcotics and Drug Abuse. 1977.
A First Report on the Impact of California's New Marijuana Law. State Capitol: Sacramento.
"The
number of [hospital] admissions directly due to marijuana use decreased
from ... 1970 to ... 1975. In the same time, the number of admissions
for drug abuse of all types, except alcohol, [also] decreased. ... The
following conclusion seem[s] warranted: medically significant problems
from the use of marijuana have decreased coincident with decriminalizing
marijuana." - P. Blachly. 1976. Effects of Decriminalization of Marijuana in Oregon.
Annals of the New York Academy of Sciences 282: 405-415.
"Data
collected at four points in time in Ann Arbor [Michigan] and the
control communities (which underwent no change in marijuana penalties)
indicated that marijuana use was not affected by the change in law [to
decriminalization.]" - R. Stuart et al. 1976. Penalty for the Possession of Marijuana: An Analysis of Some of its Concomitants.
Contemporary Drug Problems 5: 553, as cited by E. Single in The Impact of Marijuana Decriminalization: an Update.
International Studies
"The
Dutch experience, together with those of a few other countries with
more modest policy changes, provides a moderately good empirical case
that removal of criminal prohibitions on cannabis possession
(decriminalization) will not increase the prevalence of marijuana or any
other illicit drug; the argument for decriminalization is thus strong." - R. MacCoun and P. Reuter. 2001. Evaluating alternative cannabis regimes.
British Journal of Psychiatry 178: 123-128.
"Fear
of apprehension, fear of being imprisoned, the cost of cannabis or the
difficulty in obtaining cannabis do not appear to exert a strong
influence on decisions about cannabis consumption. ... Those
factors may limit cannabis use among frequent cannabis users, but there
is no evidence, as of yet, to support this conjecture."
- D. Weatherburn and C. Jones. 2001.
Does prohibition deter cannabis use? New South Wales (Australia) Bureau of Crime Statistics: Sydney.
"The
available data indicate that decriminalization measures substantially
reduced enforcement costs, yet had little or no impact on rates of use
in the United States. In the South Australian community, none
of the studies have found an impact in cannabis use which is
attributable to the introduction of the Cannabis Expiation Scheme
[decriminalization.]"
- E. Single et al. 2000. The Impact of Cannabis Decriminalisation in Australia and the United States.
Journal of Public Health Policy 21: 157-186.
"There
is no evidence to date that the CEN [decriminalization] system ... Has
increased levels of regular cannabis use, or rates of experimentation
among young adults. These results are broadly in accord with
our earlier analysis of trends in cannabis use in Australia. ...They are
also consistent with the results of similar analyses in the United
States and the Netherlands."
- N. Donnelly et al. 1999.
Effects
of the Cannabis Expiation Notice Scheme on Levels and Patterns of
Cannabis Use in South Australia: Evidence from the National Drug
Strategy Household Surveys 1985-1995 (Report commissioned for the National Drug Strategy Committee). Australian Government Publishing Service: Canberra, Australia.
"The
different laws which govern the use and sale of marijuana do not appear
to have resulted in substantially different outcomes if we view those
outcomes solely in terms of consumption patterns." - Australian Institute of Criminology, and the New South Wales Department of Politics 1997.
Marijuana in Australia, patterns and attitudes. Monograph Series No. 31, Looking Glass Press (Public Affairs): Canberra, Australia.
"While
the Dutch case and other analogies have flaws, they appear to converge
in suggesting that reductions in criminal penalties have limited effects
on drug use, at least for marijuana." - R. MacCoun and P. Reuter. 1997. Interpreting Dutch cannabis policy: Reasoning by analogy in the legalization debate.
Science 278: 47-52.
"General
deterrence, or the impact of the threat of legal sanction on the
cannabis use of the population at large, has been assessed in large
scale surveys. These studies have compared jurisdictions in the USA and
Australia where penalties have been reduced with those where they have
not, and rates of use have been unaffected. ... Since no deterrent
impact was found, this research illustrates a high-cost, low-benefit
policy in action. Therefore, if any penalty is awarded, it should be a
consistent minimum one. ...
The greatest impact on reducing the
harmful individual consequences of criminalization would be achieved by
eliminating or greatly reducing the numbers of cannabis criminals
processed in the first place." - P. Erickson and B.
Fischer. 1997. Canadian cannabis policy: The impact of criminalization,
the current reality and future policies. In: L. Bollinger (Ed.)
Cannabis Science: From Prohibition to Human Right. Peter Lang, Frankfurt, Germany. 227-242.
"There
does not appear to be a consistent pattern between arrest rates and
[marijuana] prevalence rates in the [United States] general population.
... Following precipitous increases, marijuana use began decreasing in
the late 1970s, during a period of relative stability in arrest rates.
The
general deterrence effects of the law (i.e., arrest practices), are not
apparent based on the intercorrelations of the measures presented
here." - L. Harrison et al. 1995. Marijuana Policy and Prevalance. [15] In: P. Cohen and A. Sas (Eds.)
Cannabisbeleid in Duitsland, Frankrijk en de Verenigde Staten. University of Amsterdam: Amsterdam. 248-253.
"The
evidence is accumulating ... that liberalization does not increase
cannabis use [and] that the total prohibition approach is costly [and]
ineffective as a general deterrent." - L. Atkinson and D. McDonald. 1995. Cannabis, the Law and Social Impacts in Australia.
Trends and Issues in Crime and Criminal Justice 48.
"It
has been demonstrated that the more or less free sale of [marijuana]
for personal use in the Netherlands has not given rise to levels of use
significantly higher than in countries which pursue a highly repressive
policy." - Netherlands Ministry of Health, Welfare and Sport. 1995.
Drugs: Policy in the Netherlands: Continuity and Change. The Hague.
"It
is clear ... that the introduction of the CEN scheme
[decriminalization] in South Australia has not produced a major increase
in rates of cannabis use in South Australia by comparison with changes
occurring elsewhere in Australia. ... It is not possible to
attribute the moderate increases in cannabis use rates in South
Australia to the removal of criminal penalties for small-scale cannabis
offenses in that state."
- N. Donnelly et al. 1995. The effects of partial decriminalization on cannabis use in South Australia, 1985 to 1993.
Australian Journal of Public Health 19: 281-287.
"The
available evidence suggests that those jurisdictions which have
decriminalized personal cannabis use have not experienced any dramatic
increase in prevalence of use." - National Drug and Alcohol Research Center. 1994.
Patterns of cannabis use in Australia. Monograph Series No. 27, Australian Government Publishing Service: Canberra, Australia.
"It
appears clear that there is no firm basis for concluding that the
introduction of the Cannabis Expiation Notice System in South Australia
in 1987 has had any detrimental effect in terms of leading to increased
levels of cannabis use in the Southern Australian community. ...
In
the context of a society which is increasingly well informed about the
risks associated with drug use in general, a move toward more lenient
laws for small scale cannabis offenses, such as the CEN
[decriminalization] system, will not lead to increased cannabis use." - Drug and Alcohol Services Council of South Australia, Monitoring, Evaluation and Research Unit. 1991.
The Effects of Cannabis Legalization in South Australia on Levels of Cannabis Use. DASC Press: Parkside, Australia.
One
of the most pernicious and ubiquitous effects of cannabis prohibition
is the conveyance of what traditionally should be law enforcement costs
and duties onto the public and private employers.