I am the published author of "A Modern Approach to Graham and Dodd Investing" (Wiley, 2004). The backdrop of the book was the agricultural and industrial "overfarming" of America in the 1920s, that brought about the "Dust Bowl" of the 1930s in the first instance, and the stock market crash of 1929 in the second. The book also warned of a modern version of the same thing, caused by the "disruptive" technologies of around "Y2K."