Infestation, the delightfully descriptive collective noun for a gang of cockroaches, is already being used, just as a flock of crows has a wonderful collective description - a murder.

Optimists, a rare and endangered species until recently, may be worthy of the noun used to describe a flock of owls, a parliament, if only because some people believe a parliament is full of wise people – though everyone in mining has their doubts about that!

Whatever the correct description, it was a pleasure to read last week’s column from Dryblower’ esteemed colleague, Lord Outcrop (alias Robin Bromby), who spotted the latest column from James W. Paulsen, chief investment strategist at Wells Capital Management, a division of the big US bank Wells Fargo.

What the banker saw was a turn in the global commodity sector, summed up in a snappy headline: “The only way is up for commodities”

Well-reasoned and logical, Paulsen’s thesis sits comfortably with other optimistic recent reports from rival banks, including BNP Paribas and Deutsche Bank.

What the man from Wells Fargo sees is a recovery based on seven factors that can be reduced to the irrefutable fact that commodities, as an investment class, have underperformed all other investment classes for some time, that the world is growing faster, we are continuing to consume commodities, and investors are commodity-light, which means they will want to rebalance their portfolios.

Interesting stuff no doubt, and pleasing to read if you’re in the commodities business – but wrong, according to a group of rival optimists.

Researchers at Citigroup, a US bank that is even bigger than Wells Fargo, reckon that commodity prices will not be the driver of a recovery in the mining sector – though a recovery is on the way.

If that sounds somewhat cockeyed, and a direct contradiction of Paulsen’s proposition, then you had best sit down and reach for a glass of something strong, because while Citi’s resources team does not agree with Paulsen’s case for a commodity-price rise it does agree with a mining sector recovery.

Before clicking off this page and moving to something a little easier to understand, the Citi argument is based on an assessment of financial fundamentals rather than commodity prices – and that essentially means the cost structure of the big miners.

Amusingly, Paulsen’s proposal was first published in London’s Financial Times newspaper on the same day that Citi published its counter-argument on commodities – and deeply significant advice for clients that they should start buying shares in the major diversified miners such as BHP Billiton, Rio Tinto and Glencore Xstrata.

Citigroup reckons that after spending three years as a mining-sector bear, it is has turned bullish. This is a sentiment best expressed in the heading of its latest report, Mining Fight-Back, a view it says is based on individual companies rather than a strong view on commodity prices.

While it seems to tie its argument in knots with comments such as commodity markets “moving into surplus”, but countering that with a cop out comment that “we do not expect surpluses to be a long-term feature”, the overall thrust of the Citigroup case is unquestionably optimistic, albeit for a reason similar to Paulson: it can’t get much worse.

“Our move to bullish reflects better bottom-up fundamentals, particularly for the major miners,” Citigroup said. “We would rather be too early than too late in making this call.”

On the Citigroup list of positives is a “market sentiment” assessment that is based loosely on the grieving process and a view that investors have been through the denial, bargaining, and depression phases to have now reached acceptance.

“Against this backdrop the mining companies are cutting costs, improving balance sheets and aligning with shareholders, resulting in an inflection point in the secular trend of EVA (enterprise value) creation” – long-winded banker-speak for “higher share prices ahead, prepare to open your wallets!”

There is, however, a proviso in Citi’s new-found bullish view of mining and that is the extremely selective list of recommendations.

In fact, after giving BHP Billiton, Rio Tinto and Glencore Xstrata a tick, Citi proceeds to put a cross against a much longer list of big miners, telling clients it still has sell recommendations against: Antofagasta, First Quantum, Nyrstar, New World Resources, African Barrick, Assore, Fresnilo, Hochschild, Petropavlovsk and Randgold.

Topping off the sell list is Anglo American, which Citi says is: “our least favoured large-cap miner” – a view shared by Dryblower as he watches more trouble brewing in South Africa’s mining industry, especially the platinum sector.