He became head of the Government Economic Service in 1973, and gave advice to Denis Healey. It was a hard time for Healey because the unions were asking for big pay increases and inflation was rising. Hopkin helped Healey to persuade people to stick to the pay policy he had made. Then Hopkins returned to work at the university, from where he criticized Margaret Thatcher's policies. The economy was not going well, and Mrs Thatcher wanted to make cuts in government spending. Hopkin and many other economists disagreed. They thought the government should spend money instead to help the economy.