On a new feasible set and frontier, draw
the indifference curves of the policymaker if she were to represent
two different groups of citizens (again, we assume that all
citizens in each group are identical, and the marginal utility of
consumption and environmental quality are both constant). In the
first group, A, citizens care more about environmental quality than
consumption, and in the other group, B, citizens care more about
consumption of goods and services. Explain why the optimal level of
abatement costs will differ across groups.