There is no cast-iron guarantee that the centre can direct spending much better than the localities do.

ECONOMIST: China

Rupert Todd a designer based at the centre prints designs in wax, which are then cast in precious metal.

BBC: How tech is transforming jewellery

Mr Clinton's big idea for the Democrats was to move from the left into the centre of politics, concentrate on the aspirations of the middle class, and cast off ties to special interests, especially trade unions.

ECONOMIST: Bagehot

Having wavered ahead of a presidential election on July 2nd, they shot up when the centre-right's candidate looked likely to win but fell when a recount cast doubt on the result (see article).

ECONOMIST: Emerging markets