How did we mislay half a trillion pounds? Revised data from the Office for National Statistics has just reduced the UK’s ‘net international investment position’ from a surplus of £469 billion to a deficit of £22 billion. Downing Street dismissed this as ‘a technical revision’ — and in truth it’s not as bad it sounds, since what it tells us is that we own fewer foreign assets, and foreigners own more British assets, than had previously been recorded.