Although economists say that rationing is what the price mechanism does, what most people think of as rationing is an alternative to letting prices determine how scarce economic resources, goods and services are distributed (see also queuing). Non-price rationing is often used when the distribution decided by market forces is perceived to be unfair. Rationing may lead to the creation of a black market, as people sell their rations to those willing to pay a high price (see black economy).