The gigantic offer for AstraZeneca by Pfizer is, or should be, a bellwether event. It has nothing obvious to recommend it, except that the US pharmaceuticals group should save on its tax liabilities. That the UK government – allegedly opposed to unfair tax competition – should have made this possible is bad enough. That it should have done so at the expense of one of the UK’s most important companies is worse.

Yet, because the bid seems quite so dire, it has value. It forces us to ask a big question about who ought to control the fate of companies. Should this be up to shareholders alone or do other interests matter? To answer, we must address other questions. What are companies for? Is their aim to make shareholders rich? Or is their purpose to provide valuable goods and services as cheaply and efficiently as possible?

The reason this is an excellent test case is that the bid is in an industry whose social purpose is self-evident. It is also one of the few activities in which the UK is a world leader.