TABLE 2—
Predictors of First-Time Adoption of Impaired Driving Laws: US States, 1980–2010
| Variable | Baseline Model (n = 5232), OR (95% CI) | Political Hypothesis (n = 5232), OR (95% CI) | Neighbor Hypothesis (n = 5232), OR (95% CI) | Policy Silo Hypothesis (n = 5232), OR (95% CI) | Innovativeness Hypothesis (n = 5206), OR (95% CI) |
| Population aged 15–24 y, % | 1.18* (1.03, 1.35) | 1.21* (1.03, 1.42) | 1.23* (1.04, 1.45) | 1.20* (1.03, 1.41) | 1.29* (1.03, 1.41) |
| Unemployment rate, % | 1.01 (0.94, 1.07) | 1.01 (0.94, 1.08) | 1.01 (0.95, 1.09) | 1.02 (0.96, 1.09) | 1.02 (0.96, 1.09) |
| Risk factors, MVC deaths per 1000 population | 1.01 (0.98, 1.03) | 1.00 (0.96, 1.03) | 0.99 (0.96, 1.03) | 0.99 (0.95, 1.02) | 0.99 (0.95, 1.02) |
| Health behaviors, alcohol consumption | 0.96 (0.71, 1.32) | 0.97 (0.69, 1.36) | 0.98 (0.70, 1.36) | 0.98 (0.68, 1.42) | 0.98 (0.68, 1.43) |
| Unified Republican government | 0.82 (0.32, 2.11) | 0.87 (0.34, 2.25) | 0.88 (0.35, 2.23 | 0.88 (0.34, 2.24) | |
| Divided government | 1.1 (0.68, 1.77) | 1.13 (0.70, 1.84) | 1.14 (0.70, 1.84) | 1.14 (0.70, 1.86) | |
| Liberal state ideology (0–100) | 1.01 (0.98, 1.03) | 1.01 (0.98, 1.04) | 1.01 (0.98, 1.03) | 1.01 (0.98, 1.03) | |
| Squire index | 1.2 (0.87, 1.66) | 1.23 (0.87, 1.73) | 1.2 (0.87, 1.66) | 1.19 (0.86, 1.66) | |
| Log tax per capita, $1000 | 0.78 (0.45, 1.36) | 0.8 (0.45, 1.42) | 0.71 (0.39, 1.28) | 0.71 (0.39, 1.29) | |
| Neighbors with the same policy | 1.12* (1.02, 1.22) | 1.13** (1.04, 1.24) | 1.13** (1.04, 1.23) | ||
| Has any smoking policies | 0.79 (0.55, 1.13) | 0.79 (0.56, 1.13) | |||
| Has any alcohol policies | 0.41*** (0.29, 0.58) | 0.41*** (0.29, 0.59) | |||
| Has any motor vehicle occupant safety policies | 0.94 (0.66, 1.32) | 0.93 (0.66, 1.32) | |||
| Overall policy Innovativeness score | 1.03 (0.92, 1.16) | ||||
| Federal minimum legal drinking age of 21 y, 1988 | 0.31** (0.12, 0.83) | 0.32** (0.12, 0.86) | 0.32** (0.12, 0.85) | 0.37 (0.14, 0.99) | 0.38 (0.14, 1.00) |
| AIC | 2224.896 | 2229.677 | 2225.454 | 2209.111 | 2202.806 |
| BIC | 2290.522 | 2328.115 | 2330.454 | 2333.799 | 2333.957 |
Note. AIC = Akaike information criterion; BIC = Bayesian information criterion; CI = confidence interval; MVC = motor vehicle crash; OR = odds ratio. Models also control for log population size, miles of road per capita, time, time2, and geographic divisions.
*P < .05; **P < .01; ***P < .001.