KnowraHotelling's lemmaLinked fromLinked fromThe 3 pages that link to Hotelling's lemma, each with the reason it gives.All 3Related 1Compared with 2Envelope theoremRelated: It obtains firm choices from derivatives of optimized profit.Shephard's lemmaCompared with: It is the profit-maximization counterpart to Shephard's cost-minimization result.Roy's identityCompared with: It is the producer-theory analogue of extracting choices from an optimized value function.