Table 1.

Descriptive statistics

Variables	% or mean (SD)	Range
City level (N=50)
Retail access
Sales without ID checks	10.2 (7.8)	0.0–32.5
Compliance checks (yes/no)	56	0.0–8.0
Tobacco outlet density (per 10,000 persons)	10.3 (3.3)	3.3–19.2
City demographics
Population density	4870.1 (3347.5)	1337.2–22330.2
Percentage age < 18 years	23.7 (3.2)	17.0–30.0
Socioeconomic statusa	0.0 (1.0)	−1.7–1.7
Percentage White	79.2 (14.5)	33.5–97.9
Percentage African-American	5.3 (6.3)	0.6–33.5
Percentage Hispanic	34.2 (20.2)	8.2–97.4
Individual level (N=1,478)
Age	14.6 (1.0)	13.0–16.0
Male	52.2
Hispanic	20.7
White	57.8
Observation level
Wave 1 (N=1,478)
Lifetime cigarette smoking	8.9
Perceived availability of cigarettesc (N=1,466)	2.3 (1.1)	1.0–4.0
Perceived enforcement of underage tobacco lawsc (N=1,477)	3.8 (0.8)	1.0–4.0
Wave 2 (N=1,248)
Lifetime cigarette smoking	12.7
Perceived availability of cigarettesc (N=1,240)	2.6 (1.1)	1.0–4.0
Perceived enforcement of underage tobacco lawsc	2.9 (0.8)	1.0–4.0
Wave 3 (N=1,061)
Lifetime cigarette smoking	13.7
Perceived availability of cigarettesc (N=1,054)	2.9 (1.1)	1.0–4.0
Perceived enforcement of underage tobacco lawsc	2.5 (1.0)	1.0–4.0

^aSocioeconomic status measured as a factor score derived from: median household income, percentage of population with a college education, and percentage of population unemployed.

^bMean (SD) of 1–7 point response scale

^cMean (SD) of 1–4 point response scale