Consider a world with no choice - with a monopoly supplier of an essential consumer product such as shoes. How can the consumer respond if the shoes are of poor quality, not available in the desired size or style, or if the price jumps dramatically, or if the quality of service is poor? With a monopoly supplier, any power to influence the goods or service is severely undermined. The consumer has nowhere else to go, and the supplier knows it and can abuse this position.
With choice, everything changes. If I buy my shoes from supplier A and I am not satisfied, I can go to supplier B next time. It is in supplier A's interest, then, to ensure that I do not go to B: hence there are pressures on him or her to ensure that my shoes are satisfactory.
In consumer goods, choice is desirable to protect the customer from complacent and corrupt monopoly suppliers. But it is even more important when we come to the realm of ideas and values where consumer choice becomes an important defence against indoctrination and propaganda.
Consider the dangers of having no choice of, say, newspaper. Suppose you were only allowed to read the Daily Telegraph. Day after day, you'd have to endure a Euro-sceptic, anti-welfare, pro-Major line.
Is this discussion applicable to education? If we come to education free of preconceptions about the ways schooling is organised, then I suggest that the desirability of having choice should be abundantly clear. Of course we would want to avoid a monopoly supplier who could be complacent and corrupt; insensitive to individual differences in needs, abilities and aspirations; unresponsive to community pressures; and disregarding of appropriate technological innovation.
Absolutely the last thing we should want is a monopoly supplier of educational opportunities, able to indoctrinate and inflict us with its own world-view and values, particularly one, like the state, with monopoly coercive power.
Wilby worries that choice leads to more "sink" schools, and gives an implausible example of how a good school taking over a failing one will lead to another generation of "split-site monsters". But that's not the way business "take-overs" happen elsewhere in the market. Several branches of the same company can exist in the same town without leading to split-site shops.
Subjecting producers and suppliers of consumer goods and services to the rigours of genuine competition does not lead to failing enterprises limping along, perpetuating disadvantage for those who have to patronise them.
The market is too unkind to let that happen. Even in disadvantaged areas, competing supplies of goods and services are available. Should a supplier start to go into decline, it is either quickly replaced by another or other businesses quickly expand to take demand away from it.
It is not that there are no failing restaurants, say; simply that they cannot exist as failing restaurants for very long. There is no reason why exactly the same consideration would not pertain in the education market.
But notice where this argument is leading. It is precisely that we should follow the "market to its logical conclusion" - which is much further than current reforms have taken us. Away with the state regulation of the curriculum and teaching force, away with state provision of schooling.
But even if no one is willing yet to embrace those possibilities, let's definitely not think of going back to the bad old days of catchment areas. I grew up in one of those and remember it well. We had to go to the local comprehensive whether it suited us or not. And knowing it had a captive market, the school was able to remain indifferent to us, avoiding innovation and acquiescent in low standards.
We might not like choice, but without it we are at the whim of the producer. That is the last thing we need to return to in education.
Dr James Tooley is Director of the Education and Training Unit, Institute of Economic Affairs, and University Research Fellow, School of Education, University of Manchester.