<P> Good harvests had built up a mass of 250 million bushels of wheat to be "carried over" when 1929 opened . By May there was also a winter - wheat crop of 560 million bushels ready for harvest in the Mississippi Valley . This oversupply caused a drop in wheat prices so heavy that the net incomes of the farming population from wheat were threatened with extinction . Stock markets are always sensitive to the future state of commodity markets, and the slump in Wall Street predicted for May by Sir George Paish arrived on time . In June 1929, the position was saved by a severe drought in the Dakotas and the Canadian West, plus unfavorable seed times in Argentina and eastern Australia . The oversupply would now be wanted to fill the big gaps in the 1929 world wheat production . From 97 ¢ per bushel in May, the price of wheat rose to $1.49 in July . When it was seen that at this figure the American farmers would get rather more for their smaller crop than for that of 1928, up went stocks again and from far and wide orders came to buy shares for the profits to come . </P> <P> In August, the wheat price fell when France and Italy were bragging of a magnificent harvest, and the situation in Australia improved . This sent a shiver through Wall Street and stock prices quickly dropped, but word of cheap stocks brought a fresh rush of "stags", amateur speculators and investors . Congress had also voted for a 100 million dollar relief package for the farmers, hoping to stabilize wheat prices . By October though, the price had fallen to $1.31 per bushel . </P> <P> Other important economic barometers were also slowing or even falling by mid-1929, including car sales, house sales, and steel production . The falling commodity and industrial production may have dented even American self - confidence, and the stock market peaked on September 3 at 381.17 just after Labor Day, then started to falter after Roger Babson issued his prescient "market crash" forecast . By the end of September, the market was down 10% from the peak (the "Babson Break"). Selling intensified in early and mid October, with sharp down days punctuated by a few up days . Panic selling on huge volume started the week of October 21 and intensified and culminated on October 24, the 28th, and especially the 29th ("Black Tuesday"). </P> <P> The president of the Chase National Bank said at the time: </P>

Who was an economist who warned in september 1929