The total factor cost curve reflects the degree of market control held by a firm. For a perfectly competitive firm with no market control hiring inputs under perfect competition, the total factor cost curve is a straight line that emerges from the origin. For firms with market control, including monopsony, oligopsony, or monopsonistic competition, the total factor cost curve increases at an increasing rate. The shape of the total factor cost curve thus indicates the degree of market control possessed by the factor buyer.

Total Factor Cost Curve, Monopsony

The exhibit to the right displays the total factor cost curve for a hypothetical firm, OmniKing Island Resort. This firm is the only employer of labor on a small tropical island. As the only employer of labor on the island, OmniKing is a monopsony with extensive market control, and it faces a positively-sloped supply curve. To employ more workers, OmniKing must pay a higher price.

The vertical axis measures total factor cost and the horizontal axis measures the quantity of input (workers). Although quantity on this particular graph stops at 10 workers, it could go higher.

This curve indicates that if OmniKing hires 1 worker (at $6 per worker), then it pays $6 of total factor cost. Alternatively, if it hires 10 workers (at $15 per worker), then it pays $150 of total factor cost.

For OmniKing the total factor cost "curve" really is a "curve." The slope of this curve rises as more labor is hired. The changing slope of this curve is due to the changing price.