At Hamill Manufacturing of Pennsylvania,highly skilled senior machinists are paid $70,000,excluding benefits,but the average skilled machinist generates approximately $137,000 in value added.This is partially because diminishing returns to labor cause the value of the marginal product of the last machinist hired to be less than the average of all of the machinists currently employed.

Diminishing Returns

The principle stating that as one factor of production is increased while others are held constant, a point will eventually be reached where additions of the factor yield progressively smaller increases in output.

Value Added

The increase in worth of a product or service as a result of a particular stage of production or as it moves through the supply chain.

Marginal Product

The increase in output resulting from a one-unit increase in the amount of a single input used, keeping all other inputs constant.