Wages are not set by the market in the simple sense that a commodity price is set — they are the outcome of negotiation between parties with very different power, shaped by law, custom, union density, and the availability of alternatives. The classical claim that workers are paid the value of their marginal product is, at best, an approximation that fails systematically at the bottom of the distribution. Understanding how wages are actually set explains why they so often diverge from what a worker's contribution would justify.
Zera