The average factor cost curve reflects the degree of market control held by a firm. For a perfectly competitive firm with no market control, the average factor cost curve is a horizontal line. For firms with market control, especially monopsony, the average factor cost curve is positively sloped.

Average Factor Cost Curve, Monopsony

The exhibit to the right displays the average 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 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 incurs $6 of average factor cost. Alternatively, if it hires 10 workers (at $15 per worker), then it pays $15 of average factor cost.

This positively-sloped average factor cost curve is actually nothing more than the supply curve facing OmniKing for hiring labor. In the analysis of factor markets, the average factor cost curve and the supply curve facing the firm are almost always one and the same.