The EU has adopted the ratchet principle in which it is virtually impossible to reverse the centralisation of power.

Mr Cameron also talks about undoing the acquis communautaire — the ratchet principle confirmed in the Maastricht Treaty — which commits EU nations to all previous and future centralising measures, thus ruling out the repatriation of national powers he says he seeks.

The use of current performance as a partial basis for setting future targets is an almost universal feature of economic planning. This "ratchet principle," as it is sometimes called, creates a dynamic incentive problem for the enterprise.