When is a price not a price? When it is only there to shape expectations. Nobody, one would hope, actually pays full whack for a sofa in the summer. The furniture simply sits there looking expensive until the sales arrive. Consumers consciously wait for the “special offers” and retailer plans are profitably built round, and reinforce, that psychology.

The danger now haunting policymakers is that a more corrosive form of deflationary expectations takes hold. Facing falling demand from customers, retailers have begun to discount aggressively. Consumer price data released on Wednesday show price falls in almost all categories of discretionary spending. When further price declines are anticipated, it becomes foolish to make any large, non-essential purchases.