a) State the condition for the Pareto optimal provision of a public good. Interpret the condition. b) Consider agent A with (inverse) demand curve for the public good PA = 60 - 2QA and agent B with inverse demand PR = 90 - 50, where prices are measured in f per unit. The marginal cost of producing the public good is f10 per unit. What is the Pareto efficient level of the public good? Explain. Illustrate in a graph. [Hint: Compute the marginal social benefit of the public good by adding up the demand curves vertically, over the p's] c) Describe the Vickrey-Clarke-Groves (VCG) Mechanism, provide examples and discuss problems with the VCG mechanism