The choice among these alternatives in any given case depends on the degree of difficulty consumers have in making the choice unaided, and on the con… - Kenneth Arrow

For the voucher system to work, it would be necessary to have informed parents. One cannot be dogmatic without empirical evidence, but I would be surprised if the average parent has the time or patience or competence to digest the relevant information. Indeed, one wonders where the information is to come from and in what form it should exist. Do we use test scores, themselves affected by the selection processes of the students? Impressions of individual teachers or of the physical appearance of the school will tend to dominate.

What can be concluded? We cannot be sure that the principles of democracy and socialism are compatible until we can observe a viable society following both principles. But there is no convincing evidence or reasoning which would argue that a democratic-socialist movement is inherently self-contradictory. Nor need we fear that gradual moves in the direction of increasing government intervention will lead to an irreversible move to “serfdom.”

If the total number of alternatives is two, the method of majority decision is a social welfare function which satisfies Conditions 2–5 and yields a social ordering of the two alternatives for every set of individual orderings.