Demographic characteristics of study sample
| All households | Low-income | Mid-income | High-income | |
| Number of HH’s | 31 919 | 11 422 | 15 680 | 4817 |
| Number of observations | 575 965 | 198 464 | 287 966 | 89 535 |
| Household size | 2.7 (1.3) | 2.3 (1.3) | 2.9 (1.3) | 3.2 (1.2) |
| Age of main shopper | 47.8 (15.3) | 52.4 (17.0) | 46.0 (14.3) | 42.9 (10.7) |
| Number of children if have children | 1.7 (0.8) | 1.8 (0.87) | 1.8 (0.86) | 1.7 (0.75) |
| Share of households that have children | 0.38 | 0.29 | 0.42 | 0.5 |
| Social class | % of households | |||
| Class A&B (highly skilled) | 20.2 | 5.7 | 20.9 | 52.6 |
| Class C1 | 37.6 | 30.6 | 43.1 | 36.3 |
| Class C2 | 18.0 | 15.7 | 22.4 | 9.2 |
| Class D | 13.9 | 22.0 | 11.7 | 1.7 |
| Class E (unskilled) | 10.3 | 26.1 | 1.9 | 0.3 |
| Highest qualification | % of households | |||
| Degree or higher | 24.2 | 11.64 | 25.99 | 48.02 |
| Higher education | 13.5 | 11.65 | 15.33 | 12.14 |
| A Level | 11.7 | 9.96 | 13.25 | 10.61 |
| GCSE | 18.9 | 22.38 | 18.93 | 10.8 |
| Other | 7.6 | 11.64 | 6.05 | 3.13 |
| None | 7.6 | 15.25 | 4.06 | 0.93 |
| Unknown | 16.5 | 17.48 | 16.4 | 14.37 |
| Tenure | % of households | |||
| Owned outright | 24.31 | 29.66 | 22.91 | 16.21 |
| Mortgaged | 40.09 | 17.19 | 47.64 | 69.82 |
| Rented | 29.64 | 46.42 | 23.54 | 9.72 |
| Other | 1.46 | 1.8 | 1.39 | 0.79 |
| Unknown | 4.5 | 4.89 | 4.52 | 3.47 |
Low income <£20 000 per year; mid-income £20 000 – £49 000; high-income >£50 000+.