anchor: If WTP for reductions in mortality risk is linear in risk reduction, then a WTP of $50 for a reduction of 1/100,000 implies a WTP of $500 for a risk reduction of 1/10,000 (which is ten times the risk reduction valued in the study).
positive: The WTP for reducing mortality risk might be linear.
negative: There is no way that the WTP for reducing mortality risk could be linear.