Global economic recovery 'has started': IMF chief economist

"The recovery has started. Sustaining it will require delicate rebalancing acts, both within and across countries," Blanchard said in an IMF article, released in advance of publication on Wednesday.

Blanchard cautioned that predictable models based on past recoveries from recessions would not apply to the worst global slump in seven decades.

"The world is not in a run-of-the mill recession. The turnaround will not be simple. The crisis has left deep scars, which will affect both supply and demand for many years to come," he said.