On Pareto Optimality
Part of a post from Roger Farmer (it is in today's links, but it is getting a surprising number of retweets, etc., so thought I'd highlight it further):
Why a Bottle of Beaujolais is not the same as a Collateralized Debt Obligation: ... Imagine that we dump all of the goods that exist in a big pile in the middle of a very large imaginary room. Now let the social planner allocate them to people. For example, she might give everyone equal amounts of every good. That might sound like a good idea, but some people might not drink wine. They would prefer an extra loaf of bread to a bottle of Beaujolais. That idea suggests that some ways of allocating goods are better than others. If the social planner finds a way of allocating goods among people that can’t be improved on, without making someone in society worse off, we say that that allocation is Pareto Optimal.
There is not just one Pareto Optimal way of allocating goods. There are many. And some of them are very bad from a moral perspective. For example, if the social planner gives everything to one selfish person: that allocation is Pareto Optimal. Why? Because, in order to give food to starving children we need to take it away from the selfish person. And that, by assumption, makes him worse off. Pareto Optimality is a very weak concept.
although Pareto Optimality a very weak concept it is an interesting concept because, if an allocation of goods is not Pareto Optimal, it is very bad indeed. Everybody in society, from the very richest to the very poorest person, could agree upon an intervention that would change things for the better.
Graduate students of economics learn, early in their careers, that markets allocations are Pareto Optimal. Markets may not produce outcomes that you or I judge to be morally acceptable. But they do not leave room for any obvious improvements that we could all agree upon. That idea, with a little reflection, seems to me to be obviously wrong. The ‘Global sunspots…’ paper provides one reason why.
Ok. That's the background. To understand my ‘Global sunspots paper…’ I need to go a little further by elaborating on the idea of a ‘good’. ...
Posted by Mark Thoma on Wednesday, December 30, 2015 at 08:48 AM in Economics |
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