anchor: In order for the discount to remain unchanged when Pb is changed, the price of the workshare category must be changed in an amount exactly equal to gDPb, as made clear by Equation (4).
positive: In order for the discount to remain unchanged when Pb is changed, the price of the workshare category must be changed in an amount exactly equal to gDPb
negative: In order for the discount to remain unchanged when Pb is changed, the price of the workshare category must be changed in an amount not equal to gDPb