John Maynard Keynes 
The Great Slump of 1930 [EPUB ebook] 

John Maynard Keynes, in 'The Great Slump of 1930′, wrote about the period of deflation which was the great depression at a time when it had really just started and there were more questions than answers about what was happening.
At the time of his writing, Keynes could not have known how events would have turned out and finally overcome. However, he very accurately made an assessment on the seriousness and length of the economic and political problems, being very prescient, even in 1930. He understood that 'the fundamental cause of the trouble is the lack of new enterprise due to an unsatisfactory market for capital investment.’