Table 3 Zero-inflated negative binomial model describing the relationship between a state’s total number of firearm laws and number of other states for which it is the destination of 100 or more crime-related firearms in a given year, adjusting for state-level characteristics, 2010–2017
From: Firearm laws and the network of firearm movement among US states
| Negative binomial model | ||
| Variable | b (95% CI) | Incidence Rate Ratio |
| Intercept | −2.86 (−3.41, −2.31)*** | 0.06 |
| Year | 0.10 (0.07, 0.13)*** | 1.11 |
| Poverty rate | 0.22 (0.12, 0.33)** | 1.25 |
| Density | 0.004 (−0.05, 0.05) | 1.00 |
| Area | 0.34 (0.17, 0.50)*** | 1.40 |
| Firearm ownership | −1.20 (−1.48, −0.93)*** | 0.30 |
| Number of laws | 0.55 (0.44, 0.65)*** | 1.73 |
| Census division | ||
| New England | Ref | |
| Mid-Atlantic | 2.91 (2.37, 3.45)*** | 18.30 |
| East North Central | 3.46 (2.92, 3.99)*** | 31.73 |
| West North Central | 2.74 (2.07, 3.42)*** | 15.56 |
| South Atlantic | 3.32 (2.80, 3.83)*** | 27.56 |
| East South Central | 2.96 (2.33, 3.59)*** | 19.23 |
| West South Central | 2.59 (1.95, 3.23)*** | 13.38 |
| Mountain | 1.73 (1.13, 2.33)** | 5.62 |
| Pacific | 2.28 (1.67, 2.90)*** | 9.80 |
| Zero-inflation model | ||
| Variable | b (95% CI) | Adjusted Odds Ratio |
| Intercept | −1.96 (−2.47, −1.45)*** | 0.14 |