Table 2. Marginal Effects of Store Format, Relative to Supermarkets, on Food Prices Across Food Groups, SNAP-Authorized Food Outlets in Counties With High Obesity Rates, Mississippi, 2019.
| Store Format | Marginal Effecta (SE) [P Value]b | Marginal Effect, % (95% CI)c |
|---|---|---|
| Grocery store | ||
| Beans, seeds, nuts | 0.165 (0.098) [.09] | 18.0 (−2.6 to 42.9) |
| Dairy and eggs | −0.048 (0.082) [.56] | −4.7 (−18.9 to 12.0) |
| Fruit and vegetables | 0.006 (0.049) [.90] | 0.6 (−8.6 to 10.8) |
| Grains | 0.144 (0.155) [.35] | 15.5 (−14.8 to 56.6) |
| Meats | −0.031 (0.079) [.69] | −3.1 (−17.1 to 13.2) |
| Dollar store | ||
| Beans, seeds, nuts | 0.360 (0.084) [<.001] | 43.4 (21.6 to 69.1) |
| Dairy and eggs | −0.113 (0.086) [.19] | −10.7 (−24.5 to 5.7) |
| Fruit and vegetables | −0.298 (0.056) [<.001] | −25.8 (−33.4 to −17.2) |
| Grains | 0.181 (0.146) [.21] | 19.9 (−9.9 to 59.5) |
| Meats | 0.085 (0.077) [.27] | 8.9 (−6.4 to 26.6) |
| Convenience store | ||
| Beans, seeds, nuts | 0.669 (0.110) [<.001] | 95.3 (57.5 to 142.1) |
| Dairy and eggs | 0.062 (0.112) [.58] | 6.4 (−14.7 to 32.6) |
| Fruit and vegetables | 0.303 (0.076) [<.001] | 35.4 (16.7 to 57.2) |
| Grains | 0.391 (0.172) [.02] | 47.9 (5.5 to 107.3) |
| Meats | 0.551 (0.077) [<.001] | 73.5 (49.2 to 101.7) |
Abbreviation: SNAP, Supplemental Nutrition Assistance Program.
a
Average marginal effects of store format, relative to supermarkets, on the log of food prices across food groups were estimated using the results from Model 5 in Table 1. Data were collected via store audit in July 2019.
b
Percentage difference was calculated as e ME − 1.
c
Calculated by t test.