The nature of unemployment today is totally different from what it was a year ago. It is no longer caused by a deficiency of demand. There is no longer a potential surplus supply of the things we want. The transition to full employment is hindered by two obstacles. The first is due to the difficulty of shifting labour to the points where it is wanted. The second— and, for the time being, the chief—-obstacle is caused by the difficulties, other than the shortage of labour, in the way of existing demand becoming effective.

Ch. 3 : Our Output Capacity and the National Income - How to Pay for the War (1940)