Monday, September 03, 2007

An epitaph to the RBCT

We have been alerted to a recently published comment piece in the broad sheets, which describes the folly of leaving one's brains behind while acccepting exactly what any computer programme extrudes, regardless of input.

As an epitaph to the hallowed computer modelling which fuels so much of the politically 'in the difficult file' decisions which have taken over veterinary and epidemiological policy in recent years, we reproduce it below, with thanks.

It is taken from an article by Tom Stevenson in the Daily Telegraph last week on this summer’s upheavals in the stock markets. He takes issue with the claim that “highly remunerated rocket science can be a short cut to above-average returns with below-average risk”, and continues:

“The two are as incompatible as they always have been and no spurious cocktail of calculus and Greek letters can change that fact…The admission by the biggest and most powerful investment banks that their ‘quantitative’ rocket scientists got their sums wrong undermines the claim…that ‘number crunching is leading decision makers to make different and, by-and-large, better choices’… Garbage in garbage out. If you lend money to people who cannot afford to borrow it, no statistical model or clever repackaging of the debt will make the resultant waste any less toxic. There are no short cuts…[This] kicks away support from the false idea that human experience and judgment are less important than a terabyte-crunching, mechanistic view of the world.”

The ISG final report is full of 'assumptions' and 'hypotheses', but its conclusions, built via a 'simple' mathematical model, on the back of these are now described as 'hard scientific data'. Yet the consequences explored in the report, of various policies are apparently based on the assumption of "equal risk" given to "roughly the same importance" of:

" all sources of infection for cattle, local infection for example across farm boundaries, infection from animals bought in, particularly but not only, from high incidence areas, .... and infection from wildlife, especially badgers."[ 7.24]

In the case of almost every farm, on onsite veterinary officer from local AHO could, in a couple of minutes discount two of those "rough, equal risk 'hypotheses'" and for any badger cull to proceed, should have to do so.

We liked the final paragraph of Tom Stevenson's piece, and particularly his conclusion, describing statisticians modelling of unsustainable debt which, after it had made passage through a mathematical abacas, indicated above-average returns with below-average risk. The fallout from this, its consequential share value switchback ride has finally kicked away "support for the false idea that human experience and judgment are less important than a terabyte-crunching, mechanistic view of the world.”

Not at Defra it hasn't. And if you change the stuff about the consequences of lending to people who can’t afford to borrow, to killing cattle without dealing with all sources of infection, this would make a perfect epitaph to the RBCT Badger Dispersal Trial.

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