Hotelling's Lemma

Definition

Hotelling's Lemma:
If y(p) is single valued, then is differentiable and

Where:
y(p) is supply correspondence
π(p) is profit function

If we regard y as output and z as input, and let profit function to be π(p, w), then:

See also:

• Shepard's Lemma
• Roy's Identity

Note

Example