In VoxEU this week (excerpt):
Commodity prices: Over a hundred years of booms and busts
Andrew Powell 28 April 2015
Commodity prices are very persistent. A boom is always followed by a bust, and after a slump, a boom comes along. This column reviews some basic aspects of commodity theory and their role in the last boom. Finally, it presents arguments stating that lower commodity prices are here to stay for a while. We may have to wait many years for the next boom to come along.
Commodity prices are very persistent. During booms we seem to forget that they have always (yes, always) been followed by busts (see Figure 1). And during a slump we forget that a boom is surely going to come along— we just have to wait long enough. What determines such booms and busts? Was the last boom exceptional? Where are prices today relative to long-run trends? And the big question – where are prices likely to go from here?
Great article on the history of commodity prices from the 1900s to the present. If Mr Powell is correct, we're in for a loooooong wait. And this is even without accounting for the relative prices of commodities against manufactured goods.