I once asked a free-market economist how he would analyse the Irish famine, which is sometimes seen as an example of too much free trade: while people starved, ship-loads of food were leaving Ireland weekly.
“The lesson of the Irish famine is,” quoth he, “never be over-dependent on one crop, or one source.” The single crop on which so many were dependent was, of course, the potato.
I do not know whether this advice always works in practice. There may be situations in which people have no alternative but to depend on one crop. But translated into non-agricultural terms, it’s surely sensible always to have a Plan B, or back-up, to any system.
