Figure 1.

Demand curves for patients’ willingness-to-pay for pain reductions for patients with chronic low back pain and chronic neck pain WTP values were trimmed above the 99^th percentile for back pain to $1000 for reducing pain to zero and $536 for reducing pain by half. Maximum WTP values reported for back pain were $10,000 per month for reducing their pain to zero and $2,000 per month for reducing pain by half. Trimming WTP values above the 99^th percentile for neck pain reduced those values to $1000 for reducing pain to zero and $500 for reducing pain by half. Maximum WTP values reported for neck pain were $1,000,000 per month for reducing their pain to zero or by half.