Look carefully at depressed assets, as opposed to overvalued assets, in any investment arena. However, they are usually several years ahead of the end user of the product and as a result are often well into their own form of recession well before it occurs elsewhere. As demand decreases, production slows down and a period of entrenchment occurs. Plants are closed, workers laid off and production decreases. The supply of raw materials begins to shrink, often to a degree that creates a shortage.
Cyclical trends are well documented, with data going back in some cases, several hundred years.
Whether it be grains, oil and gas, base metals or cotton, years of excess supply followed by more years of dwindling production will have assisted in creating shortages. This may be good for precious metals. It is worth remembering that today most commodity markets are at all time lows and that precious metals are also well below their previous highs. It is worth noting that usually one type of market advances at the expense of the other. An example of this is the current bull market in stocks which began in 1982, after the commodities boom began to decline in early 1980.