Cannabis Column: How Much Pot Do Americans Consume?

Jon Gettman is a long time contributor to HIGH TIMES. A former National Director of NORML, Jon has a Ph.D. in public policy and regional economic development and consults with attorneys, advocates, and non-profits on cannabis related research and public policy issues. On October 8, 2002, along with a coalition of organizations, he filed a new petition to have cannabis rescheduled under federal law. This column will track that petition's progress.

How Much Pot Do Americans Consume?

Analysis for the legalize and tax debate.

Just how much marijuana do people actually consume? Related questions include just how many marijuana users are there, how often do they use marijuana, and how much do they consume?

Recent survey data released by the National Survey on Drug Use and Health (NSDUH) indicates 25.8 million people have acknowledged using marijuana in the past year, of which 15.2 million have acknowledged using marijuana in the past month. These figures have remained pretty much the same throughout this decade since the NSDUH improved their survey techniques in 2002 and realized that there were actually about 25% more marijuana users than they had been previously estimating.

These figures, though, only represent the minimum estimates of the number of marijuana users. The Office of National Drug Control Policy (ONDCP) has acknowledged that it is reasonable to inflate such estimates by one-third to account for under-reporting. While they don’t like to admit it, they understand that not everybody is forthcoming (that is, honest) when asked by a survey to report on illegal drug use. An ONDCP publication notes that while researchers disagree on the subject of under-reporting on drug use surveys, survey-based estimates of tobacco use, for example, only reveal about 75% of the actual tobacco using population.

NSDUH also provides data on the frequency of marijuana use, that is, how many days a year people who report their use actually use marijuana. This data can be found in Table 7.1A and is summarized here. The NSDUH figures suggest the following profile of marijuana use in the United States:

· 10.6 million users smoke marijuana about six times a year

· 4 million users smoke marijuana once or twice a month (about 18 times a year)

· 2.3 million users smoke marijuana about once a week (about 52 times a year)

· 3.4 million users smoke marijuana about twice a week (about 104 times a year)

· 5.4 million users smoke marijuana almost daily (about 300 times a year)

There is an interesting lack of awareness in academic and drug policy articles about just how much marijuana people consume whenever they use marijuana. There is also a lack of awareness about even the basic issue of how much marijuana is contained in a single marijuana cigarette. One ONDCP report on what Americans spend on illegal drugs uses a figure of .4 grams of marijuana per cigarette to generate consumption estimates. (The same report is also based on NSDUH survey results derived before the survey’s accuracy was improved in 2002.) Government issued marijuana cigarettes for research purposes, though, contain about .8 grams of marijuana and this is generally viewed as being a reasonable representation of the weight of marijuana cigarettes in use today. Factor in the seeds, stems, spillage, and other waste and it’s reasonable to estimate that a joint represents about 1 gram of marijuana, and that users get 28 joints of marijuana out of an ounce. This is important in estimating consumption because most of the available survey data on how much people use when they consume marijuana is expressed in terms of joints.

Another important factor to consider is that people develop tolerance to marijuana, so experienced users usually consume more than occasional users. Plus, most of the people who use marijuana regularly really like it, and consequently they use a lot of it. Some of them use a bit too much, some of them indeed have dependency and abuse issues, but then on the other hand, many individuals who use a lot of marijuana have no such issues and simply like the effects of the drug. Many individuals also actually use marijuana for medical reasons, such as to remedy chronic pain, and need to use the drug frequently. Regardless of the reasons for use, there is a lot of evidence that many frequent users of marijuana consume a lot of it.

For example, in a 1993 study by Stephens, Roffman and Simpson nearly 50% of the sample of frequent marijuana users recruited for the study used marijuana four times or more per day. In another 1994 study by Stephens, Roffman and Simpson a sample of near-daily users of marijuana averaged marijuana use of about four times per day. A 1997 study by Chen, Kandel, and Davis based on NSDUH survey data reports daily marijuana consumption in the range or one, two, three and four or more, with about 25% of daily users reporting use of three or more joints per day. (The NSDUH used to be called the National Household Survey. Many studies, such as this 1997 one refer to it by that name.) These studies are dated, but they provide confirmation that daily marijuana users consume a lot of marijuana.

The usage frequency described above provides five levels of marijuana use. A simple model for estimating total US consumption can be based on associating each level of use with an ascending number of joints. For example, those using marijuana six times a year use one joint each time. The next group, that uses marijuana once or twice a month, uses two joints each time. The two groups that use marijuana weekly, once or twice a week, are assigned three joints for each time of use. The group that uses marijuana on practically a daily basis is assigned four joints for each time.

This model subsequently accounts for the use of 17.9 million pounds of marijuana annually, about 8,105 metric tons. If the using estimates provided by NSDUH under-report marijuana use by one-third, adjusting for this accounts for 23.8 million pounds or 10,807 metric tons. Both of these figures are less than widely used estimates of the overall supply of marijuana according to US government reports. The supply numbers may be too large, or the usage estimates much too small. It is reasonable, though, to conclude the truth is somewhere in between.

In any event, consumption estimates will be important in the emerging debate over the legalization of marijuana. Consumption estimates are essential to estimating potential tax revenue. Figuring out a fair and effective basis for marijuana-related taxes requires a bit of thought, discussion, and eventually a bit of political horse-trading. But here’s something that underscores why this subject of consumption estimates will be receiving a lot of attention in the near future. If Americans consume close to 24 million pounds of marijuana annually, that amounts to 384,000,000 ounces. If marijuana was taxed at a flat rate of $25 per ounce, that would generate close to $10 billion in tax revenue annually. $10 billion provides a useful revenue stream for government, no matter how it is split between the federal, state, and local governments. Marijuana taxes will likely be higher, but the eventual retail price will certainly be lower than it is under prohibition. And with billions in tax revenues flowing in, governments will be just as happy about the situation as marijuana users.