People should earn for their labors, but only for the useful effort and sacrifice they expend. This is what people can themselves adjust in response to the incentive of payment. We pay people to put up with the sacrifices involved in doing labor. This is also what is meritorious and deserves pay. They shouldn?t get more, for example, if they have better or worse equipment, if they happen to be in a highly valued or less highly valued pursuit, if they happen to be born larger or smaller or with a quicker or less quick sense of melody or programming talent. It is only for useful effort and sacrifice that people should be paid, either morally or as an economic incentive, but the amount paid should reflect the outlay of effort, not the value of the product.