TABLE 2—
Overall Synthetic Control Results for Purchaser Licensing Laws: Connecticut and Missouri, 1995 and 2007
| Firearm |
Nonfirearm |
|||||
| Model | MSPE | Effect, % | Placebo No./Total No. (%)a | MSPE | Effect, % | Placebo No./Total No. (%)a |
| Homicide | ||||||
| Connecticut 1995 purchaser licensing | 0.371 | −27.8 | 1/38 (0.03) | 0.089 | −0.7 | 20/33 (0.61) |
| Missouri 2007 purchaser licensing repeal | 0.257 | +47.3 | 0/6 (0.00) | 0.037 | +18.1 | 0/8 (0.00) |
| Suicide | ||||||
| Connecticut 1995 purchaser licensing (through 2017) | 0.109 | −32.8 | 2/35 (0.06) | 0.008 | −3.3 | 15/25 (0.60) |
| Connecticut 1995 purchaser licensing (through 2006) | −23.2 | −3.2 | ||||
| Connecticut 1995 purchaser licensing (2007–2017) | −40.5 | −3.4 | ||||
| Missouri 2007 purchaser licensing repeal | 0.208 | +23.5 | 0/7 (0.00) | 0.065 | +6.9 | 1/4 (0.25) |
Note. MSPE = mean square predicted error.
a
The placebo results reported are the proportions of control states that had a more extreme placebo effect estimate than the effect actually estimated for the true treated state. We restricted the denominator to the subset of donor states with prelaw MSPEs less than 5 times the treated state’s prelaw MSPE.