TABLE 1—
Descriptive Statistics of 8th-, 10th-, and 12th-Grade Students Surveyed From 1991 Through 2000 for the Monitoring the Future Project
| Variable | Mean (SD) |
| Age, y | 15.4951 (1.7588) |
| Age squared, y | 243.1929 (54.8835) |
| Male | 0.4863 (0.4998) |
| Race/ethnicity | |
| African American | 0.1249 (0.3306) |
| Hispanic | 0.1010 (0.3013) |
| Asian American | 0.0320 (0.1759) |
| Native American | 0.0199 (0.1397) |
| Other race | 0.0482 (0.2142) |
| Parents’ education | |
| Father has less than high school education | 0.1265 (0.3324) |
| Father has at least some college | 0.4977 (0.5000) |
| Mother has less than high school education | 0.1211 (0.3263) |
| Mother has at least some college | 0.5179 (0.4997) |
| Real earned income, $ per wk | 19.5628 (26.7354) |
| Real income other sources, $ per wk | 9.7046 (15.0295) |
| Grade 8 | 0.3691 (0.4826) |
| Grade 10 | 0.3195 (0.4663) |
| Year surveyed | |
| 1991 | 0.0996 (0.2994) |
| 1992 | 0.1027 (0.3036) |
| 1993 | 0.1041 (0.3054) |
| 1994 | 0.1017 (0.3022) |
| 1995 | 0.1043 (0.3057) |
| 1996 | 0.1001 (0.3002) |
| 1997 | 0.1031 (0.3041) |
| 1998 | 0.1012 (0.3017) |
| 1999 | 0.0918 (0.2887) |
| Real per capita tobacco control expenditures, $ per y | 0.4826 (1.17) |
| Real price of cigarettes, cents per pack | 133.7460 (27.0426) |
| Clean indoor air index | 14.5393 (10.8701) |
| Youth access index | 12.3708 (7.1315) |
| Purchase use possession index | 1.0790 (1.0318) |
| Tobacco-producing state | 0.1294 (0.3357) |
| Region of the United States | |
| New England | 0.0524 (0.2228) |
| East North Central | 0.1842 (0.3877) |
| West North Central | 0.0784 (0.2688) |
| South Atlantic | 0.1655 (0.3717) |
| East South Central | 0.0669 (0.2498) |
| West South Central | 0.1203 (0.3254) |
| Mountain | 0.0596 (0.2368) |