# A2 Revision – Pareto Efficiency

In the A2 exam there is usually one multiple-choice question on Pareto Efficiency and part of an essay.  The idea of Pareto Efficiency is named after the Italian Economist Vilfredo Pareto. For a given set of consumer tastes, resources, and technology, an allocation is Pareto-efficient, if there is no other feasible allocation that makes some people better off and nobody worse off. See also a previous post – Pareto Optimality and the perfect wave.

The figure above shows an economy with only two people, Susie and David. The initial allocation at A gives David QD goods and Susie QS goods. Provided people assess their own utility by the quantity of that they themselves receive, B is a better allocation than A which in turn is a better allocation than C. But a comparison of A with points such as F, D or E, requires us to adopt a value judgment about the relative importance to us of David’s and Susie’s utility. It is important to note from the figure the following:

• If you move from A to B or A to G it is a Pareto gain – A to B both Karen and John are better off. A to G Susie is better off, David no worse off.
• If point B or G is feasible then point A is Pareto-inefficient – more goods can be consumed
• A move from A to D makes David better off and Susie worse off. However we need to make a judgment about the relative value of David’s and Susie’s utility before we can comprehensively state that David is better off. Therefore the Pareto principle is limited in comparing allocations on efficiency – it only allows us to evaluate moves to the north-east and south-west

Therefore, we need look at the economy as whole and how many goods it can produce. In the Figure above the frontier AB shows the maximum quantity of goods which the economy can produce for one person given the quantity of goods being produced for the other person. All points on the frontier are pareto-efficient. David can only be made better off by making Susie worse off and vice versa. The distribution of goods between David and Susie is much more equal at point C than at points A or B. Note that:

Anywhere inside the frontier is Pareto-inefficient – some can be made better off without making the other worse off.

The economy should never choose an inefficient allocation inside the frontier. Which of the efficient points on the frontier (A, B, C) is the most desirable will depend on the value judgment about the relative value of David and Susie utility.

Source: Economics by Begg