Scarcity rents.
wConstrained input limits the production of output.
$/Q
Q/t
MR
D
C
PA
QA
wPrice is above cost, but firm has no incentive to restrict output.
w(PA – C)QA is a scarcity rent.
wIf the firm owns all of the constrained factor, it keeps the rent.
wIf the firm has to buy the factor on a competitive market, it bids the factor price up to (PA – C).
Rent goes to the factor owner.
This analysis follows Winter (1995, pp. 159-167).