Britain’s new Prime Minister Andy Burnham has signalled his support for a written constitution for the UK, which unlike most countries, does not have one authoritative document. Since entering office just two weeks ago, the former mayor of Greater Manchester has made devolution of power to regional authorities a focus of his administration. “In the end, I think it does start to point towards a new constitutional settlement,” Burnham said of his devolution plans. Calling for a “new clear set of...