Table 2.
Exponential random graph model for counts of traced firearm transfers for 2015–2017 from origin states to destination states. Dependent variable, node characteristics and edge characteristics square root transformed. Bolded estimates have p < 0.05. Incidence rate ratios are abbreviated IRR. Confidence intervals are abbreviated CI.
| Model 1 | Model 2 | Model 3 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IRR | (95% | CI) | p-value | IRR | (95% | CI) | p-value | IRR | (95% | CI) | p-value | |
| Origin State | ||||||||||||
| Population (1 million) | 1.659 | 1.569 | 1.755 | <0.001 | 1.378 | 1.268 | 1.498 | <0.001 | 1.428 | 1.298 | 1.570 | <0.001 |
| Median household income ($10,000) | 1.009 | 0.614 | 1.660 | 0.971 | 0.537 | 0.277 | 1.038 | 0.064 | ||||
| Firearm laws | ||||||||||||
| Count | 0.891 | 0.840 | 0.946 | <0.001 | 0.879 | 0.834 | 0.926 | <0.001 | 0.885 | 0.813 | 0.963 | 0.005 |
| Background checks (%) | 0.964 | 0.921 | 1.009 | 0.113 | 1.043 | 0.962 | 1.131 | 0.309 | ||||
| Buyer laws (%) | 0.925 | 0.872 | 0.980 | 0.009 | 0.895 | 0.832 | 0.962 | 0.003 | ||||
| Concealed carry laws [referent] | 0.994 | 0.956 | 1.034 | 0.757 | 1.000 | |||||||
| Dealer laws (%) | 1.021 | 0.954 | 1.094 | 0.545 | 1.037 | 0.984 | 1.092 | 0.176 | ||||
| Firearm trafficking laws (%) | 1.073 | 1.025 | 1.124 | 0.002 | 1.077 | 1.008 | 1.149 | 0.027 | ||||
| Prohibitions against high-risk persons (%) | 0.999 | 0.953 | 1.046 | 0.954 | ||||||||
| Other laws (%) | 0.962 | 0.917 | 1.009 | 0.115 | 1.021 | 0.960 | 1.084 | 0.511 | ||||
| Destination State | ||||||||||||
| Population (1 million) | 1.452 | 1.353 | 1.558 | <0.001 | 1.515 | 1.391 | 1.650 | <0.001 | ||||
| Median household income ($10,000) | 0.790 | 0.505 | 1.237 | 0.303 | 0.610 | 0.343 | 1.084 | 0.092 | ||||
| Firearm laws | ||||||||||||
| Count | 1.104 | 1.057 | 1.152 | <0.001 | 1.081 | 1.009 | 1.159 | 0.027 | ||||
| Background checks (%) | 1.155 | 1.074 | 1.241 | <0.001 | ||||||||
| Buyer laws (%) | 0.981 | 0.909 | 1.060 | 0.634 | ||||||||
| Concealed carry laws [referent] | 1.000 | |||||||||||
| Dealer laws (%) | 0.906 | 0.857 | 0.958 | 0.001 | ||||||||
| Firearm trafficking laws (%) | 1.070 | 0.999 | 1.145 | 0.052 | ||||||||
| Prohibitions against high risk persons (%) | 1.032 | 0.981 | 1.086 | 0.228 | ||||||||
| Other laws (%) | 1.032 | 0.967 | 1.101 | 0.340 | ||||||||
| Geographic Characteristics | ||||||||||||
| Distance (1,000 kms) | 0.349 | 0.269 | 0.455 | <0.001 | 0.290 | 0.220 | 0.383 | <0.001 | ||||
| Adjacent | 2.494 | 1.903 | 3.268 | <0.001 | 2.625 | 1.956 | 3.523 | <0.001 | ||||
| Network Structure | ||||||||||||
| Individual heterogeneity | 1.656 | 1.173 | 2.337 | 0.004 | 2.100 | 1.589 | 2.775 | <0.001 | ||||
| Mutuality | 2.212 | 1.727 | 2.833 | <0.001 | 1.801 | 1.225 | 2.649 | 0.003 | ||||
| Over-dispersion | 0.003 | 0.001 | 0.012 | <0.001 | 0.005 | 0.001 | 0.029 | <0.001 | ||||
| Diagnostics | ||||||||||||
| Akaike Information Criterion | −970 | −1767 | −1790 | |||||||||
| Bayesian Information Criterion | −918 | −1698 | −1652 | |||||||||
| Potential Scale Reduction Factor | 1.380 | 1.150 | 1.430 | |||||||||