Double Counting

In the distant past I worked in accounts and was often involved in organising stocktakes. One thing that I always had to consider was how to avoid double counting, the act of counting something twice because it appeared under two different but not mutually exclusive categories. It appears that double counting is rife in the Government and the media just don't query it. There are loads of examples and some day I might even try and do a long list, but for now just the one example - Gordon Brown proudly announced the go ahead for two new aircraft carriers, the same two aircraft carriers that Tony Blair announced last year.