(a) Suppose that the Hong Kong government imposes a per unit tax of $100 on smartphone sellers. Use a diagram of a smartphone market to indicate and explain the changes in the price paid by buyers, price received by sellers, quantity transacted, tax revenue, tax incidence, consumer surplus, producer surplus, total surplus, and deadweight loss. Provide clear labels in your diagram.

(b) What is the relationship between the marginal product of labor and the marginal cost?