A Proposed Modification of Taylor's Demand Analysis: Comment

In estimating demand functions for electricity, it is inappropriate to use as a variable (in addition to marginal price) either average price for blocks other than the final one or total payment for blocks other than the final one. It is appropriate to use (in addition to marginal price) a variable equivalent to a lump-sum payment the customer must make before buying as many units as he wants, at the marginal price.