Participation and Consumption of Illegal Drugs among Adolescents
Duarte, Rosa, Escario, Jose Julian, Molina, Jose Alberto, International Advances in Economic Research
This paper identifies the determinants affecting the adolescent populations' decision regarding whether or not to consume illegal drugs. The authors estimate a simultaneous Type II Tobit model for each sample substance, including marijuana, LSD, amphetamines, cocaine, volatile substances, and heroine. The data are drawn from three Spanish Surveys on Drug Use in the School Population conducted in 1994, 1996, and 1998. The results indicate that illegal drug use among Spanish adolescents is clearly determined by economic variables. It is similarly determined by other sociodemographic variables, such as personal habits, family environment, and the receipt of information regarding the negative consequences of drug use. (JEL D81, I10, K42, D12)
The use of illegal drugs, particularly among adolescents, imposes a number of individual and social costs. These include increased crime [Silverman and Spruill, 1977; Simonds and Kashani, 1980; Benson et al., 1992; Resignato, 2000], health problems [Tommasello, 1982; Nahas and Latour, 1992; Polen et al., 1993; Pope et al., 1995], and employment or school difficulties [White et al., 1988; Kaplan and Liu, 1994; Yamada et al., 1996; Mijares, 1997; Mensch and Kandel, 1988; Bray et al., 2000; MacDonald and Pudney, 2000a, b; 2001; French et al., 2001]. Apart from these clearly significant aspects, two additional factors require analysis: (1) the addictive nature of drug use, where individuals who have started to consume find that they cannot quit the habit and must go on consuming [DeFonseca et al., 1997; Grossman and Chaloupka, 1998; Samhsa, 1998] and (2) the testing of the gateway theory, which states that there is a systematic sequencing in the use of addictive substances that begins with alcohol and cigarettes, continues on to marijuana, and leads finally to hard drugs such as cocaine, heroine and LSD [Chaloupka and Laixuthai, 1997; DeSimone, 1998].
In addition to these studies, which reflect the socioeconomic relevance of illegal drug abuse, papers published by [Gill and Michaels, 1991] and [Saffer and Chaloupka, 1999] provide specific and significant evidence on the determinants of this pattern of behaviour. Gill and Michaels use the National Longitudinal Surveys of Youth corresponding to 1980 and 1984 in order to estimate a Probit equation that explains the individual decision to use illegal drugs. They find that non-economic factors dominate the decision to participate in the illegal drug market. Saffer and Chaloupka employ the National Household Surveys of Drug Abuse corresponding to 1988, 1990, and 1991 in order to estimate various Probit specifications for different illegal drugs. Their main contribution is the use of prices to estimate price elasticities of participation, i.e., -0.28 for cocaine and -0.94 for heroin. Although these two papers undoubtedly offer relevant contributions, they both focus on the significant participation equation, assuming it is an empirical measure of consumption. However, neither one has paid any attention to the specific factors that determine the quantity of illegal drugs that the individual will demand.
The public problem of illegal drug use is a widespread phenomenon in many countries of the developed world and is especially worrying among the adolescent population. Although it is well established that illegal drug use among this age group is significant in the United States, it is also prevalent in other countries, such as Spain. A comparison of the Spanish rates derived from the Spanish Surveys on Drug Use in the School Population conducted in 1994, 1996, and 1998 with those corresponding to the U.S. homogenous participation rates obtained from the Youth Risk Behavior Surveys conducted in 1995, 1997, and 1999 confirms this reality. Indeed, the situation in Spain would appear to be even bleaker. U.S. data now reveal a decreasing trend in the adolescent use of marijuana (rates have fallen from 26% in 1995 to 24% in 1999) and a stable trend in the use of cocaine of about 3. …