How much competition is enough? Many important markets are dominated by a few large companies. The big four accountancy firms undertake the audits of almost all large corporations. Most current accounts are held at a small number of retail banks. You have a choice of perhaps three or four mobile phone networks. The list of similar oligopolies can easily be extended.

In all these industries, established businesses will tell you that they welcome competition. But, these companies will often explain, enough is enough. Users already have a wide choice of products and suppliers. Measures to encourage new entry, or to prevent incumbents from making mergers and acquisitions, or – worst of all – to give others access to the facilities these incumbents have expensively constructed, are certainly inappropriate and probably harmful.

The background is one in which many private and public monopolies have been dismantled. In telecommunications your choice for 100 years was to take what the local telephone provider offered or to leave it. But consumers now have a bewildering variety of choice. They certainly don’t need more. The priorities of public policy should be directed elsewhere – to promoting investment and innovation. Global competitiveness, not domestic competition, is what matters. Government departments and regulators have been more and more ready to accept these arguments.