Consider an economy with two types of goods, a public good G and a private good z. There are two people in the economy (i = 1, 2) whose preferences are given by the utility function: Ui(zi , G) = Gzi , i = 1, 2. Each individual has the same initial endowment m. The public good can be produced by converting one unit of income (endowment) into one unit of the public good, i.e., c = 1.

a. Find the efficient level of public good provision.

b. Find the provision level of G if it is financed by voluntary contributions. Is the outcome efficient?