Appendix Q. Contingent Valuation Results: Children
After the parents had completed the Discrete Choice Experiment, they were asked two open ended Contingent Valuation Method (CVM) questions.
First, they were asked what is the most they would be willing and able to pay to remove their child’s FHS for a temporary period. They were then asked what is the most they would be willing and able to pay to remove their child’s condition permanently.
Child CVM Results: Temporary Removal
Respondents were asked what is the most they are willing to pay for the removal of their child’s FHS for a predefined number of years removal. They were randomly assigned one of: 1 year, 3 years and 5 years.
Child CVM Results: Temporary Removal, Aggregate
The mean WTP values for 1 year, 3 years or 5 years of removal for the pooled data (not disaggregated by condition) are £1603, £4134 and £6581 respectively, the median values are £250, £1000 and £1500 respectively
Table 1. Summary statistics: Whole Sample by Removal Period
Removal period | mean | sd | N | min | p25 | Median | p75 | max |
---|---|---|---|---|---|---|---|---|
1 year | 1603.32 | 4383.3 | 201 | 0 | 2 | 250 | 1000 | 30000 |
3 years | 4134.48 | 11205.04 | 196 | 0 | 4.5 | 1000 | 3000 | 100000 |
5 years | 6581.04 | 16403.43 | 197 | 0 | 5 | 1500 | 5000 | 100000 |
Child CVM Results: Temporary Removal, by Condition
The mean WTP values for 1 year, 3 years or 5 years of removal of food allergy for a child are £716, £1681, £2135 respectively, the median values are £100, £300 and £500 respectively – these median values correspond to a WTP value of £100/year.
Table 2. Summary statistics: Food Allergy by Removal Period
Removal period | mean | sd | N | min | p25 | Median | p75 | max |
---|---|---|---|---|---|---|---|---|
1 year | 2117.3 | 5132.63 | 141 | 0 | 0 | 500 | 1200 | 30000 |
3 years | 4134.02 | 11648.04 | 127 | 0 | 0 | 1000 | 3000 | 100000 |
5 years | 6745.29 | 16437.02 | 137 | 0 | 4 | 1200 | 5000 | 100000 |
The mean WTP values for 1 year, 3 years or 5 years of removal of coeliac disease for a child are £342, £7504 and £10833 respectively, the median values are £75, £1500 and £1500 respectively. As reported elsewhere, we note the small sample size of parents of children with coeliac disease and these small numbers were randomly assigned to one of three temporary durations, further reducing the sample size for specific durations of removal.
Table 3. Summary statistics: Coeliac Disease by Removal Period
Removal period | mean | sd | N | min | p25 | Median | p75 | max |
---|---|---|---|---|---|---|---|---|
1 year | 342.3 | 451.91 | 20 | 0 | 0 | 75 | 500 | 1500 |
3 years | 7504.3 | 15765.21 | 24 | 0 | 51 | 1500 | 5000 | 75000 |
5 years | 10833.6 | 26867.3 | 21 | 0 | 0 | 1500 | 5000 | 100000 |
The mean WTP values for 1 year, 3 years or 5 years of removal of food intolerance for a child are £422, £2339 and £3714, the median values are £125, £300 and £2500 respectively.
Table 4. Summary statistics: Food Intolerance by Removal Period
Removal period | mean | sd | N | min | p25 | Median | p75 | max |
---|---|---|---|---|---|---|---|---|
1 year | 422.1 | 812.98 | 40 | 0 | 75 | 125 | 500 | 5000 |
3 years | 2338.6 | 5337.22 | 45 | 0 | 15 | 300 | 2000 | 30000 |
5 years | 3714.2 | 4738.6 | 39 | 0 | 500 | 2500 | 5000 | 25000 |
The relationship between the amount a respondent is willing to pay and the removal period is monotonic. For the adults there was greater consistency between the annualized WTP values across the condition than is the case for parents responding regarding temporary relief for their children: the WTP values for food intolerance are lower than for food allergy or coeliac disease.
Figure 2 Distribution of open ended WTP by period: children
Child CVM Results: Permanent Removal
The mean WTP value for permanent removal of the child’s condition for the pooled data is £16912, the median value was £5000.
Table 5: Maximum willingness to pay for permanent removal of child’s only/worst condition, aggregate.
- | mean | Std. Dev. | N | min | p25 | Median | p75 | Max |
---|---|---|---|---|---|---|---|---|
Maximum WTP | 16912.15 | 27294.25 | 698 | 0 | 500 | 5000 | 20000 | 100000 |
The mean WTP values for permanent removal of a child’s food allergy, coeliac disease and food intolerance are £16982, £19820 and £6648 respectively.
Table 6: Maximum willingness to pay for permanent removal of child’s only/worst condition.
Only or worst condition | mean | sd | N | min | p25 | Median | p75 | max |
---|---|---|---|---|---|---|---|---|
Coeliac disease | 16981.6 | 26893.22 | 70 | 0 | 1000 | 5500 | 20000 | 100000 |
Food Allergy | 19819.7 | 29458.99 | 489 | 0 | 1000 | 5000 | 25000 | 100000 |
Food Intolerance | 6648.4 | 14004.47 | 139 | 0 | 200 | 1000 | 10000 | 100000 |
The WTP values of parents regarding their children are significantly higher than those for adults regarding their own conditions. As with temporary removal the parents WTP regarding food intolerance were much lower than those for food allergy or coeliac disease which were of a similar magnitude.