Different prices are charged for different quantities or "blocks," of the same good. Here,there are three blocks,with corresponding prices Pi,P2, and P3.There are also economies of scale,and average and marginal costs are declining.Second-degree price discrimination can then make consumers better off by expanding output and lowering cost. Different prices are charged for different quantities or “blocks,” of the same good. Here, there are three blocks, with corresponding prices P1 , P2 , and P3 . There are also economies of scale, and average and marginal costs are declining. Second-degree price discrimination can then make consumers better off by expanding output and lowering cost