" Substantial differences were found in perceived availability of the various drugs. In general, the more widely used drugs are reported to be available by higher proportions of the age group, as would be expected (see Tables 9-6, 9-7, and 9-8). Also, older age groups generally perceive drugs to be more available. For example, in 2013, 39% of 8th graders said marijuana would be fairly easy or very easy to get (which we refer to as 'readily available'), versus 70% of 10th graders and 81% of 12th graders. In fact, compared to 8th graders, the proportion of 12th graders indicating that drugs are available to them is two to four times as high for other drugs included in the study and five times as high for narcotics other than heroin. (Tranquilizers, on the other hand, are reported as only a little less available by 8th graders.) Both associations are consistent with the notion that availability is largely attained through friendship circles. (A section in Chapter 10 documents where 12th graders obtain prescription drugs that are not medically prescribed, and friends clearly are the leading source.) The differences among age groups may also reflect less willingness and/or motivation on the part of those who deal drugs to establish contact with younger adolescents. Because many inhalants — such as glues, butane, and aerosols — are universally available, we do not ask about their availability. See Table 9-8 for the full list of drugs included in the questions for 12th graders; a few of these drugs were not asked of the younger students (see Tables 9-6 and 9-7).
" Measures on the availability of cigarettes are not included in the 12th-grade questionnaires because we have assumed that they are almost universally available to this age group. However, data on this measure are collected from 8th and 10th graders, which clearly show that cigarettes are readily available to most of them. In 2013, 50% of 8th graders and 71% of 10th graders thought that cigarettes would be fairly easy or very easy for them to get if they wanted some.
" The great majority of teens also see alcohol as readily available: In 2013, 56% of 8th graders, 77% of 10th graders, and 90% of 12th graders said it would be fairly easy or very easy to get."
Johnston, L. D., O’Malley, P. M., Bachman, J. G., Schulenberg, J. E. & Miech, R. A. (2014). Monitoring the Future national survey results on drug use, 1975–2013: Volume I, Secondary school students. Ann Arbor: Institute for Social Research, The University of Michigan, pp. 452-453.