social planner

In welfare economics, a social planner is a hypothetical decision-maker who attempts to maximize some notion of social welfare. The planner is a fictional entity who chooses allocations for every agent in the economy—for example, levels of consumption and leisure—that maximize a social welfare function subject to certain constraints (e.g., a physical resource constraint, or incentive compatibility constraints). This so-called planner's problem is a mathematical constrained optimization problem. Solving the planner's problem for all possible Pareto weights (i.e., weights on each type of agent in the economy) yields all Pareto efficient allocations.