"Prior to 1981, daily use of cigarettes among 12th graders was generally inversely related to SES, with each successively higher SES group smoking less (Figure 5-12f). Between 1981 and 1991, this ordinal relationship diminished substantially because (a) the two highest SES groups showed some gradual increase in use; (b) the next two strata remained unchanged; and (c) the lowest SES group showed a decline in use, which brought it from the highest smoking stratum to the lowest (probably due to its racial composition, as will be discussed in the next section). The net result of this and other trends was a near elimination of the SES differences among 12th-grade students in daily cigarette smoking. From 1992 to 1997, all strata showed an increase in daily smoking.

"From 1997 to 2003, there were sharp declines in smoking in the two highest SES strata— with later and slower downturns in the other strata—once again opening up some differences by SES, though not as large as the differences that existed in the 1970s and 1980s. This time the lowest SES stratum is not at the top but rather down near the bottom of the rankings—again, likely because of its racial composition.

"It is possible that the introduction of the Joe Camel advertising campaign in 1988 helped account for the closing of the socioeconomic gap in the late 1980s, and that its termination in 1997 helped account for the re-emergence of that gap. We know that between 1986 and 1997, the rise in smoking was sharper among 12th-grade boys than 12th-grade girls, and the Camel brand was particularly popular among boys and those whose parents had higher than average education.72 So, the Joe Camel ad campaign appears to have been particularly effective with boys from more educated strata, raising the smoking rate of their SES strata and nearly eliminating the relationship between SES and smoking that existed before and after the years of the campaign for that brand."

Source

Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2013). Monitoring the Future national survey results on drug use, 1975–2012: Volume I, Secondary school students. Ann Arbor: Institute for Social Research, The University of Michigan.