I would argue that all of the G.O.P. candidates are calling for policies that would be deeply destructive at home, abroad, or both. But even if you like the broad thrust of modern Republican policies, it should worry you that the men and woman on that stage are clearly living in a world of fantasies and fictions.

My Book – the one that has stayed with me for four-and-a-half decades – is Isaac Asimov’s Foundation Trilogy, written when Asimov was barely out of his teens himself. I didn’t grow up wanting to be a square-jawed individualist or join a heroic quest; I grew up wanting to be Hari Seldon, using my understanding of the mathematics of human behaviour to save civilisation.

OK, economics is a pretty poor substitute; I don't expect to be making recorded appearances in the Time Vault a century or two from now. But I tried.

On the contrary, this familiarity, the way Asimov's invented societies recapitulate historical models, goes right along with his underlying conceit: the possibility of a rigorous, mathematical social science that understands society, can predict how it changes, and can be used to shape those changes...

That conceit underlies the whole story arc. In Foundation, we learn that a small group of mathematicians have developed "psychohistory", the aforementioned rigorous science of society...

The first half of the Foundation series manages, however, to have the structure of prophecy and destiny without the mysticism; it's all about the laws of psychohistory, you see, and Hari Seldon's prescience comes from his mathematics...

Foundation isn't about the triumph of the middle class, either. We never get to see the promised Second Empire, which may be just as well, because it probably wouldn't be very likeable. Clearly, it's not going to be a democracy – it's going to be a mathematicized version of Plato's Republic, in which the Guardians derive their virtue from the axioms of psychohistory...

Now that I'm a social scientist myself, or at least as close to being one as we manage to get in these early days of human civilisation, what do I think of Asimov's belief that we can, indeed, conquer that final frontier – that we can develop a social science that gives its acolytes a unique ability to understand and perhaps shape human destiny?

Well, on good days I do feel as if we're making progress in that direction. And as an economist I've been having a fair number of such good days lately.

I know that sounds like a strange claim to make when the actual management of the economy has been a total disaster. But hey, Hari Seldon didn't do his work by convincing the emperor to change his policies – he had to conceal his project under a false front and wait a thousand years for results. Now, there isn't, to my knowledge, a secret cabal of economists with a thousand-year plan to save our current civilisation (but then I wouldn't tell you if there was, would I?). But I've been struck these past several years by just how much power good economics has to make correct predictions that are very much at odds with popular prejudices and "common sense"...