We tested the sensitivity of the value of the output of laundry services to:

• using different average weekly washloads - if only 3 loads of washing on average are washed per week the total value of laundry services is reduced by 30 per cent, and increased by 30 per cent if the average is 7 loads per week;
• using different service wash prices - the upper quartile price of the 36 observations increases the total value of laundry services by 9 per cent, the lower quartile price reduces the total value by 12 per cent in 2000;
• using different percentages of washload ironed - if only 8 per cent of all washloads are ironed, the total value of laundry services is reduced by 5 per cent, if 20 per cent of all washloads are ironed, the total value increases by 24 per cent in 2000;
• using different ironing prices - the upper quartile price of the 22 observations increases the total value of laundry services by 6 per cent, the lower quartile price reduces the total value by 6 per cent in 2000.