'From an age of shortage to an age of enough?" as Barclays put it in a report, just released. They believe the commodities super cycle, which began in 1999, has reached its end. At almost the same time, Citigroup's veteran oil watcher Ed Morse declared the cycle was breathing its last.
The super cycle was driven by rapid Asian industrialisation, above all in China, requiring meat for more affluent consumers; petrol, steel and aluminium for new cars; copper and concrete for the apartments of megacities from Dubai to Mumbai to Shanghai.
China used 12 per cent of all industrial metals in 2000; by 2011, it devoured 40 per cent.
Soaring demand collided with a long period of under-investment in new fields, farms and mines, and oil prices went from US$10 to $145 per barrel, rice from $162 per tonne to $1,015, nickel from $5,000 per tonne to $50,000.
The boom in different commodities interacted: scarce steel drove up the cost of oil platforms and pipelines; expensive petroleum encouraged biofuels to take away farmland from food, and made mechanised agriculture and fertilizers costly. Nationalising governments from Venezuela and Argentina to Russia and Kazakhstan, South African platinum to Kyrgyz gold, were eager to reap their share of the rewards.
These booms inevitably bring with them concerns about resource exhaustion.
In the 1970s, we had Malthusian prophets of overpopulation, and the bestselling study "Limits to Growth". The 2000s brought much obsessing over "peak oil", followed by books on Peak Everything and The End of Food.
But the long history of commodity booms seems to show a distinct pattern: a decade of rising prices, following by two decades of declines, as technology and investment in new supply catch up. The last great boom, of the 1960s and early 1970s, was led by affluence in North America and Western Europe. Now China may be slowing from the past decade's torrid pace, and Citi expects a shift from heavy capital investment towards more services and consumption.
Even continuing robust Chinese growth will now meet countervailing factors - ageing populations in Europe, Japan and increasingly China itself; high debt and slow growth in developed countries; and action against climate change, emphasising resource efficiency.
Some caution is necessary when calling the end of the boom. When oil and metals prices fell in May 2011, when Chinese demand slowed in May last year, and again when BHP Billiton cancelled US$40 billion (Dh146.91bn) of Australian mining projects in August, analysts trumpeted the end of the boom.
Chinese demand still has a long way to expand, even at a slower rate. Its urbanisation may not run its course until 2030. India, with 1.2 billion people, has not begun really resource-intensive growth. Africa, with another billion inhabitants, is yet farther behind.
The key theme, then, is not so much a crash - but increasing differentiation, by product and geography. Copper and nickel may be needed less, while other metals, such as platinum and aluminium, feature heavily in consumer goods. Coal may lose ground to cleaner fuels; gas is cheap in North America but still costly in Asia.
Droughts triggered by climate change, sprawling cities and desertification, and overfishing will contend with more meat-heavy diets. Geopolitical upsets can still strike major producing countries.
For investors, this puts a premium on choosing the right commodities and companies, not simply surfing the super cycle. Companies have to continue to invest, but more selectively, while cutting boom-era costs. Resource-rich countries - Canada, Australia, Russia, Brazil, Saudi Arabia - are about to learn just how much of the past decade's growth was because of the genius of their economic management.
And if consumers don't get a windfall, they may at least enjoy some respite from soaring prices.
We are not moving from an age of anxiety to one of abundance - but of simple sufficiency.
Robin Mills is the head of consulting at Manaar Energy, and the author of The Myth of the Oil Crisis and Capturing Carbon
