Changes

Suppose for example, that the principal (the purchaser) has a preference for durability of the product as well as price. One solution is to create a scoring rule to force bidders to incorporate both types of information:

where <math>s_i\,</math> is the score for firm <math>i\,</math>, <math>b_i\,</math> is their price bid, and <math>d_i\,</math> is there durability bid. <math>f(\cdot)\,</math> is a function that weights the inputs according to the principal's requirements.