Final answer:
In a purely competitive resource market, the marginal factor cost stays the same as the quantity of resource hired increases, since each additional unit of resource is hired at a constant market price.
Step-by-step explanation:
In a purely competitive resource market, the cost of hiring an additional unit of a resource, such as in the case of wages for labor, is reflected in the marginal factor cost (MFC). When a firm operates in such a market, the supply of the resource is perfectly elastic, meaning that firms can hire as much of the resource as they need at the market price without affecting the price of the resource itself. Therefore, as the quantity of resource hired increases, the extra cost of hiring an additional unit, or the marginal factor cost, stays the same because each unit is hired at the same market price.
If however, wages were to increase, this would lead to an increase in costs of production and could cause some firms to make economic losses, resulting in a shift of the supply curve to the left and a higher market price, as indicated in the provided information. But this situation would be due to a change in wage rates, not due to the increase in the quantity of resource hired under conditions of perfect competition.