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Third and Final Call for The Reassessment of the Use and Promotion of Info-Gap Decision Theory in Australia

At the end of 2006 I launched a campaign to contain the spread of info-gap decision theory (IGDT) in Australia. This campaign, which laid out a rigorously argued analysis showing that this theory is fundamentally flawed, was by and large prompted by the concerted effort of a number of Australian research centres to promote this theory in Australia.

In 2008 I issued a call for the reassessment of the use and promotion of this theory in Australia, and in 2011 I renewed this call.

I now issue a third and final call for such a reassessment. The reason for my making this a final call is that there are clear indications that my campaign is beginning to bear fruit.

For instance, consider the following extract from the recently published article: Severe Uncertainty and info-gap decision theory by Hayes, Barry, Hosack, and Peters (2013) in the journal Methods in Ecology and Evolution:

"... Ecologists and managers contemplating the use of IGDT should carefully consider its strengths and weaknesses, reviewed here, and not turn to it as a default approach in situations of severe uncertainty, irrespective of how this term is defined. We identify four areas of concern for IGDT in practice: sensitivity to initial estimates, localised nature of the analysis, arbitrary error model parameterisation and the ad hoc introduction of notions of plausibility. ..."

"... The literature and discussion presented in this paper demonstrate that the results of Ben-Haim (2006) are not uncontested. Mathematical work by Sniedovich (2008, 2010a) identifies significant limitations to the analysis. Our analysis highlights a number of other important practical problems that can arise. It is important that future applications of the technique do not simply claim that it deals with severe and unbounded uncertainty but provide logical arguments addressing why the technique would be expected to provide insightful solutions in their particular situation. ..."

See full paper at

Similarly, there are clear signs that other info-gap scholars begin to realize that info-gap decision theory is unsuitable for the treatment of a severe uncertainty of the type that this theory claims to address. And there are also signs that info-gap scholars begin to realize that info-gap's robustness model is a reinvention of a staple model of local robustness, known universally as "radius of stability" (circa 1960).

In short, info-gap scholars begin to realize that the theory is a reinvented wheel, and a square one at that.

Risk analysts who continue to stick to their guns that a reinvented model of local robustness that deals with small perturbations in a nominal value of a parameter can properly handle a severe, non-probabilistic uncertainty, would do well to read Hayes et al.'s (2013) analysis of info-gap decision theory, as well as the articles posted at

And scholars looking for examples illustrating that the revered peer-review process is not foolproof, should examine the long list of publications on info-gap decision theory for fascinating and intriguing examples of this type. For instance, this peer-reviewed literature would have us believe that a model of local robustness is a reliable tool for the treatment of "black swans" and even "unknown unknowns"!!! See

Diehard info-gap adherents will no doubt continue to propagate the misleading/erroneous rhetoric that has become part and parcel of this theory, and some peer-reviewed journals will continue to publish this rhetoric. See

Indications therefore are that the literature on info-gap decision theory will continue to supply vivid illustrations of Bob Bedow's (1977) 7th Natural Law of Operations Analysis: It is better to extend an error than to admit to a mistake.

Moshe Sniedovich
The Land of the Black Swan
May 14, 2013

Disclaimer: This page, its contents and style, are the responsibility of the author (Moshe Sniedovich) and do not represent the views, policies or opinions of the organizations he is associated/affiliated with.

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