With unemployment on the up, the name Arthur Okun - the man who invented the misery index - is being bandied about among a range of economists for the first time in years, including individuals working at the International Monetary Fund and asset manager M&G.

Okun, not exactly a cheerful soul, devoted much of his life to the study of recessions between World War II and 1960. He argued in favour of higher taxes to better distribute the wealth of nations. But he is best known for inventing the misery index by combining the rates of unemployment and inflation.