The idea behind this, roughly similar to the Carney argument for a nominal GDP target, is that the only way to stimulate activity, in a deeply deflationary environment is to convince people and businesses that you really will spend whatever it takes to ensure that prices and nominal demand will be higher next year than they are today.

BBC: New Year messages from Japan

On that basis Mr White thinks the Fed was right to pursue the first round of quantitative easing, since nominal GDP was falling, but wrong to pursue a second round with activity recovering.

ECONOMIST: Buttonwood

Second, individuals are given a nominal boost based on their Klout scores, which is a third-party measure of social-media activity.

WSJ: Methodology for NYIndex