The members of an economy—the firms, the consumers, the investors, and the government—make choices. To give a common name to them all, I will refer t… - Kenneth Arrow

The problem I have with utilitarianism is not that it is excessively rational, but that the epistemological foundations are weak. My problem is: What are those objects we are adding up? I have no objection to adding them up if there's something to add. But the one thing I retain from utilitarianism is that, basically, judgements are based on consequences. Certainly that's the sort of thing we do in the theory of the single individual under uncertainty; you make sure utility is defined only over the consequences. I view rights as arrangements which may help you in achieving a higher utility level.

My own interest first centered on the relations between Pareto efficiency and competitive equilibrium. In particular, there was considerable discussion among economists in the late 1940’s about the inefficiencies resulting from rent control and different proposals for arriving at the efficiency benefits of a free market by one or another transition route. Part of the informal efficiency arguments hinged on the idea that under rent control people were buying the wrong kind of housing, say, excessively large apartments. It struck me that an individual bought only one kind of housing, not several. The individual optima were at corners, and therefore one could not equate marginal rates of substitution by going over to a free market. Yet diagrammatic analysis of simple cases suggested to me that the traditional identification of competitive equilibrium and Pareto efficiency was correct but could not be proved by the local techniques of the differential calculus.

The competitive system can be viewed as an information and decision structure. Initially, each agent in the economy has a very limited perspective. The household knows only its initial holdings of goods (including labor power) and the satisfactions it could derive from different combinations of goods acquired and consumed. The firm knows only the technological alternatives for transforming inputs into outputs. The “communication” takes the form of prices. If the correct (equilibrium) prices are announced, then the individual agents can determine their purchases and sales so as to maximize profits or satisfactions. The prices are then, according to the pure theory, the only communication that needs to be made in addition to the information held initially by the agents. This makes the market system appear to be very efficient indeed; not only does it achieve as good an allocation as an omniscient planner could, but it clearly minimizes the amount of communication needed.