Estimated percentage change in calories (kcal) purchased due to incentives across the household purchasing distribution
| Dependent variable: calories (kcal) purchased | Biscuits (% change) | Crisps (% change) | Savoury snacks (% change) | χ2-test of equality |
| 10% Price reduction—mean | 4.3*** (4.2 to 4.4) | 8.8*** (8.5 to 9.1) | 6.4*** (6.2 to 6.6) | 979.4*** |
| 10% Price reduction—25th percentile | 4.6*** (4.5 to 4.7) | 9.1*** (8.8 to 9.5) | 7.1*** (6.9 to 7.3) | – |
| 10% Price reduction—median | 4.3*** (4.2 to 4.4) | 8.8*** (8.5 to 9.2) | 6.4*** (6.2 to 6.6) | – |
| 10% Price reduction—75th percentile | 4.1*** (4.0 to 4.2) | 8.5*** (8.2 to 8.8) | 5.7*** (5.5 to 5.9) | – |
| Any price promo.—mean | 37.0*** (35.8 to 38.2) | 7.5*** (6.1 to 8.9) | 26.4*** (24.9 to 27.9) | 950.0*** |
| Any price promo.—25th percentile | 35.6*** (34.3 to 37.0) | 5.7*** (4.1 to 7.4) | 24.2*** (22.5 to 25.9) | – |
| Any price promo.—median | 37.0*** (35.8 to 38.2) | 7.5*** (6.0 to 8.9) | 26.4*** (24.6 to 28.1) | – |
| Any price promo.—75th percentile | 38.4*** (37.3 to 39.5) | 9.3*** (8.0 to 10.6) | 28.7*** (27.5 to 29.9) | – |
| Any volume promo.—mean | 72.9*** (71.3 to 74.6) | 52.3*** (50.2 to 54.4) | 77.8*** (75.7 to 79.8) | 380.6*** |
| Any volume promo.—25th percentile | 87.1*** (85.2 to 89.1) | 58.1*** (55.3 to 61.0) | 88.5*** (85.9 to 91.0) | – |
| Any volume promo.—median | 72.8*** (71.3 to 74.3) | 52.3*** (50.3 to 54.3) | 77.9*** (76.0 to 79.8) | – |
| Any volume promo.—75th percentile | 59.8*** (58.5 to 61.2) | 46.6*** (44.6 to 48.7) | 67.6*** (66.0 to 69.2) | – |
| Observations | 199 886 | 135 399 | 118 654 | – |
| Households | 3024 | 3024 | 3024 | – |
95% CI in brackets **p < 0.05, ***p < 0.01.
Price variable refers to a 10% price change (coefficient for a 1% change available in the online supplemental appendix).
Price promotion variable refers to all price promotions pooled.
Volume promotion variable refers to all volume promotions pooled.
Number of observations within categories varies based on the number of purchases per household.
All models include age of main shopper, age2 of main shopper, household size, time in panel (years), time since last purchase (weeks), and year dummies (full result available in online supplemental appendix).