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Reviews of publications on Info-Gap decision theory

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Last modified: Saturday, 17-Jul-2010 23:50:09 MST

On this page I comment on publications dealing with Info-Gap decision theory. Although this commentary is intended primarily for the benefit of the authors and reviewers of these publications, it clearly lends support to and justifies the rationale behind my Info-Gap Campaign.

Requests for reviews of Info-Gap publications that are not currently on the list will be considered.

Latest News   April 18, 2010 Added a discussion entitled When the Info-Gap Spin Goes Marching in! February 19, 2010 Added a review report on Robust decisions for declaring eradication of invasive species by Tracy M. Rout, Colin J. Thompson, and Michael A. McCarthy. November 26, 2009 Created a new directory called Info-Gap Economics July 12, 2009 Added a review report on Heterogeneous uncertainties in cholesterol management by Yakov Ben-Haim, Clifford C. Dacso, Jonathon Carrasco, and Nithin Rajan. June 30, 2009 Added a discussion on Myth and Facts about Info-Gap Decision Theory June 27, 2009 Added a PDF file of a presentation entitled How do you recognize a Voodoo decision theory? (RMIT June 26, 2009). June 22, 2009 Added a discussion on Reinventing a Square Wheel. June 15, 2009 Added a preliminary review report on the recently published paper An info-gap approach to managing portfolios of assets with uncertain returns by Beresford and Thompson. June 11, 2009 Added a discussion on the Too Good to be True! syndrome. June 6, 2009 Added a tutorial A Guided Tour of Info-Gap's Robustness Model and Some of its Fundamental Flaws June 1, 2009 Added a review report on Do we know how to set decision thresholds for diabetes? by Y. Ben-Haim, M. Zacksenhouse, C. Keren, and C.C. Dacso. May 23, 2009 Added a short discussion entitled A Short Second Opinion on Info-Gap Decision Theory. May 10, 2009 Added a short discussion on Laplace's Principle of Insufficient Reason. May 9, 2009 The PDF file of the seminar entitled Black Swans, Modern Nostradamuses, Voodoo Decision Theories, Info-Gaps, and the Science of Decision-Making in the Face of Severe Uncertainty is now available. May 5, 2009 Added a short discussion on Bayes Rule vs Maximin Rule, indicating that the latter is not an instance of the former. April 28, 2009 Added a review report on a new refereed Info-Gap paper by Lior Davidovitch, Richard Stoklosa, Jonathan Majer, Alex Nietrzeba, Peter Whittle, Kerrie Mengersen, Yakov Ben-Haim. April 24, 2009 Added a page providing some criticism of Bueno de Mesquita's theories. It is linked to the page New Nostradamuses. April 14, 2009 The bug in the "Comments" facility was fixed. You can now post your comments anonymously. April 9, 2009 New "Decision-Making Under Severe Uncertainty" site launched. April 5, 2009 A page dedicated to "reviews of publications on Info-Gap decision theory" is now available. March 31, 2009 An experimental "Your comments, please!" facility is now onboard. Give it a try. March 26, 2009 A very interesting Freudian Info-Gap slip! March 24, 2009 First major sign of progress! See comments on Hall and Harvey's (2009) new intriguing assumption regarding the likelihood of deviations from the estimate. March 24, 2009 A new section on Modern alchemy, Freudian slips, quick-fixes and suchlike was added.

Overview Selection criteria How to read the reviews Reviews Factland Articles, papers, notes Lectures, seminars

Overview

Over the past two years I have been asked, on several occasions, the following intriguing question:

Given that the flaws in Info-Gap decision theory are so obvious and grave, how do you explain the large number of publications on Info-Gap, particularly the significant number of articles published by refereed journals?

My usual answer to this question is as follows:

I'll be happy to discuss this matter with you over a cup of coffee (skinny latte, please!)

I do not plan to deviate from this answer here.

However, I believe that the reviews that I provide here will give you a good idea of what I may tell you over a cup of coffee so, try to read between the lines. And, for a fuller appreciation of one of the central points that I am making in this collection of reviews, read the discussion on fog, spin and rhetoric. Because, as you will see, whatever Info-Gap decision theory lacks in substance and rigor, is made up for, and covered up, by heavy fog, spin, and rhetoric.

I use the acronym TUIGF as shorthand for "The usual Info-Gap flaws". These flaws are discussed in detail in my compilation of FAQs about Info-Gap so there is no need to elaborate on them in these reviews. On the other hand, they will be used as benchmarks.

I also use the acronym SNHNSNDN as shorthand for "see nothing, hear nothing, say nothing, do nothing". This refers to authors who, for various reasons, choose to ignore my criticism of Info-Gap decision theory, particularly my theorems proving that Info-Gap's robustness model is a Maximin model (circa 1940) and Info-Gap's opportuneness model is a Minimin model (circa 1952). For your convenience and enjoyment these beauties are displayed at the bottom of the page.

So, recall that Info-Gap's two main fundamental flaws are:

• It propounds severe misconceptions about its place and role in decision theory:
  Info-Gap decision theory is hailed as new, revolutionary and radically different from all current theories for decisions under uncertainty. But the fact of the matter is that its robustness model is just a simple Maximin model (circa 1940) and its opportuneness model is just a simple Minimin model (circa 1952). The situation is further exacerbated by Ben-Haim's repeated futile attempts to show that Info-Gap's robustness model is not a Maximin model.

  The proof is straightforward: see the Maximin Theorem at the bottom of the page.

• It fails to tackle the severity of the uncertainty that it professes to manage:
  Info-Gap is hailed as a methodology that is designed specifically for decision-making under severe uncertainty. Yet, a superficial examination of its robustness and opportuneness models suffices to immediately reveal that not only do these models fail to tackle the severity of the uncertainty, they ignore the severity of the uncertainty altogether. More specifically, these models are local in that they explore, in the first instance, the immediate neighborhood of a given estimate. Since under conditions of severe uncertainty the estimate is a poor indication of the true value of u and is likely to be substantially wrong, these models are in violation of the Garbage In -- Garbage Out (GIGO) Axiom. This is the reason for my proclaiming Info-Gap decision theory a classic example of voodoo decision-making.

  See the No Man's Land and Invariance Theorems at the bottom of the page.

The question therefore arises: how is it that so many Info-Gap papers have been published in refereed journals? Surely, the flaws are so obvious that any referee with a basic knowledge of decision-making under severe uncertainty should have been able to identify them.

Indeed, even more basic is the point that Info-Gap scholars who should know better continue to publish Info-Gap papers, repeating the same unsubstantiated claims, again and again and again.

The objective of my reviews is to show these publications for what they are.

Selection criteria

I do not have strict criteria for the selection of papers for review. For obvious reasons I prefer the more recent papers that were published in refereed journals. But I shall consider other papers, including working papers -- if they shed new light on on the failings of Info-Gap decision theory and its applications.

So the plan is to start with recently (2009) published papers, especially papers that attempt to deal with my criticism.

If you have come across a publication that you think ought to be reviewed, please send me a copy of it and I shall have a look at it to see if it is suitable for this project.

How to read the reviews

I realize that the potential readership of my reviews may be diverse with various interests and degrees of knowledge of decision theory in general and Info-Gap decision theory in particular.

My aim is to address my reviews, in the first instance, to the authors of the articles, the referees who reviewed them, the editors of the journals who accepted the papers for publication, and the bodies that provided the funds to support the work on which the articles are based. So, please read the reviews with this point in mind.

• My reviews are based on the (unrealistic) assumption that you have read the original publications.


• If you are conversant with classical decision theory you should be able to make sense of my reviews even if you have not read the publications themselves.


• Recall that according to Info-Gap decision theory, the robustness of decision d is defined as follows:

  α(d,û) = max {α≥0: r(d,u) ≥ r*, ∀u∈U(α,û)}

  where:

  • d = decision;
  
  
  • u = parameter of interest whose true value is subject severe uncertainty;
  
  
  • û = estimate of the true value of u;
  
  
  • α = size of the region of uncertainty;
  
  
  • U(α,û) = uncertainty region of size α centered at û
  
  
  • r* = critical level of performance;
  
  
  • r(d,u) = level of performance attained by decision d if the true value of the parameter of interest is u;
  
  
  • The constraint r(d,u) ≥ r* is referred to as the "performance requirement".

  Let U denote the complete region of uncertainty. Roughly, this is a set that contains U(α,û) for all α≥0.

Any assessment of Info-Gap's contribution to the state of the art in decision theory must be made against these claims by Ben-Haim (2001, 2006) — the Father of Info-Gap:

Info-gap decision theory is radically different from all current theories of decision under uncertainty. The difference originates in the modeling of uncertainty as an information gap rather than as a probability. The need for info-gap modeling and management of uncertainty arises in dealing with severe lack of information and highly unstructured uncertainty.

Ben-Haim (2006, p. xii)

and

In this book we concentrate on the fairly new concept of information-gap uncertainty, whose differences from more classical approaches to uncertainty are real and deep. Despite the power of classical decision theories, in many areas such as engineering, economics, management, medicine and public policy, a need has arisen for a different format for decisions based on severely uncertain evidence.

Ben-Haim (2006, p. 11)

So my reviews address primarily the following two questions:

• Is Info-Gap radically different from classical decision theories?


• Does Info-Gap tackles the severity of the uncertainty?

As indicated above, the fact of the matter is that Info-Gap decision theory fails on both counts. So, it should come as no surprise that my criticism of Info-Gap decision theory is very harsh indeed.

The following mini-guide may be useful to some readers.

Reader type	Tips
Author	Please, read the relevant FAQs cited in my reviews before you send me an angry letter. I'd be most happy to discuss your paper with you.
Referee	If you were not vigilant enough, or not sufficiently au fait with the literature on decision-making under severe uncertainty, make sure that next time you are better prepared before you proceed to referee an Info-Gap paper. In any event, take note that Info-Gap's fundamental flaws cannot be smoothed over by fancy rhetoric.
Editor	Make sure that you send Info-Gap papers to qualified referees. Please, do not send me Info-Gap papers for review.
Info-Gap aficionado	Relax! You can ignore my criticism. This is in fact what Info-Gap scholars -- with some exceptions -- have done so far.
Inactive Info-Gap Critic	Wake up! Join my campaign.
PhD Student	Indeed, not everything that gets published in refereed journals is "correct". Also, PhD supervisors are not always well-versed in the subject matter and can fall victim to the adverse effects of spin and rhetoric. Therefore, study carefully the claims that are made in the Info-Gap literature.
Grantor of research funds	Read carefully the research proposals. If a proposal is too good to be true, then rest assured that it is. In the case of decision-making under severe uncertainty, watch out for voodoo decision theories that are in violations of the GIGO Axiom, but are dressed up by spin.
Accidental tourist	It would be a good idea to read the first 20 items in FAQs about Info-Gap decision theory before reading the reviews.

I shall expand the list as required as we continue with this project. If you can't wait, send me a note about your very special Reader-type.

Reviews

1. Ben-Haim (2001, 2006): Info-Gap Decision Theory: decisions under severe uncertainty.


2. Regan et al (2005): Robust decision-making under severe uncertainty for conservation management.


3. Moilanen et al (2006): Planning for robust reserve networks using uncertainty analysis.


4. Burgman (2008): Shakespeare, Wald and decision making under severe uncertainty.


5. Ben-Haim and Demertzis (2008): Confidence in monetary policy.


6. Hall and Harvey (2009): Decision making under severe uncertainty for flood risk management: a case study of info-gap robustness analysis.


7. Ben-Haim (2009): Info-gap forecasting and the advantage of sub-optimal models.


8. Yokomizo et al (2009): Managing the impact of invasive species: the value of knowing the density-impact curve.


9. Davidovitch et al (2009): Info-gap theory and robust design of surveillance for invasive species: The case study of Barrow Island.


10. Ben-Haim et al (2009): Do we know how to set decision thresholds for diabetes?


11. Beresford and Thompson (2009): An info-gap approach to managing portfolios of assets with uncertain returns.


12. Ben-Haim, Dacso, Carrasco, and Rajan (2009): Heterogeneous uncertainties in cholesterol management.


13. Rout, Thompson, and McCarthy (2009): Robust decisions for declaring eradication of invasive species.

Let me know of any articles/books that you think should appear on this list.

In addition to a brief commentary on the Info-Gap content of the publications, I also provide TUIGF, SNHNSNDN and GIGO scores (%).

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This contribution is dedicated to the Info-Gap people at Wikipedia. They were searching for a formal proof that ....

 

Fact 1: Info-Gap is a simple instance of Wald's Maximin model [1945].

Fact 2: Info-Gap does not deal with severe uncertainty: it simply ignores it.

Recent Articles, Working Papers, Notes

Also, see my complete list of articles

• Sniedovich, M., (2010) A classic decision theoretic perspective on worst-case analysis, Applications of Mathematics, in press.


• Sniedovich, M., (2010) Black swans, new Nostradamuses, voodoo decision theories and the science of decision-making in the face of severe uncertainty, International Transactions in Operations Research, in press.


• Sniedovich, M., (2010) A bird's view of Info-Gap decision theory, Journal of Risk Finance, 11(3), 268-283.


• Sniedovich, M. (2010) Dynamic programming: introductory concepts, in Wiley Encyclopedia of Operations Research and Management Science (EORMS), Wiley, in press.


• Sniedovich, M., (2010) Dynamic Programming: Foundations and Principles, Second Edition,, Francis and Taylor, in press.


• Caserta, M., Voss, S., Sniedovich, M. (2010) Applying the corridor method to a blocks relocation problem, OR Spectrum, in press.


• Sniedovich M. (2009) Modeling of robustness against severe uncertainty, pp. 33- 42, Proceedings of the 10th International Symposium on Operational Research, SOR'09, Nova Gorica, Slovenia, September 23-25, 2009.


• Sniedovich M. (2009) A Critique of Info-Gap Robustness Model. In: Martorell et al. (eds), Safety, Reliability and Risk Analysis: Theory, Methods and Applications, pp. 2071-2079, Taylor and Francis Group, London.
.

• Sniedovich M. (2009) A Classical Decision Theoretic Perspective on Worst-Case Analysis, Working Paper No. MS-03-09, Department of Mathematics and Statistics, The University of Melbourne, (PDF File)


• Caserta, M., Voss, S., Sniedovich, M. (2008) The corridor method - A general solution concept with application to the blocks relocation problem. In: A. Bruzzone, F. Longo, Y. Merkuriev, G. Mirabelli and M.A. Piera (eds.), 11th International Workshop on Harbour, Maritime and Multimodal Logistics Modeling and Simulation, DIPTEM, Genova, 89-94.


• Sniedovich, M. (2008) FAQS about Info-Gap Decision Theory, Working Paper No. MS-12-08, Department of Mathematics and Statistics, The University of Melbourne, (PDF File)


• Sniedovich, M. (2008) A Call for the Reassessment of the Use and Promotion of Info-Gap Decision Theory in Australia (PDF File)


• Sniedovich, M. (2008) Info-Gap decision theory and the small applied world of environmental decision-making, Working Paper No. MS-11-08
  This is a response to comments made by Mark Burgman on my criticism of Info-Gap (PDF file )


• Sniedovich, M. (2008) A call for the reassessment of Info-Gap decision theory, Decision Point, 24, 10.


• Sniedovich, M. (2008) From Shakespeare to Wald: modeling wors-case analysis in the face of severe uncertainty, Decision Point, 22, 8-9.


• Sniedovich, M. (2008) Wald's Maximin model: a treasure in disguise!, Journal of Risk Finance, 9(3), 287-291.


• Sniedovich, M. (2008) Anatomy of a Misguided Maximin formulation of Info-Gap's Robustness Model (PDF File)
  In this paper I explain, again, the misconceptions that Info-Gap proponents seem to have regarding the relationship between Info-Gap's robustness model and Wald's Maximin model.


• Sniedovich. M. (2008) The Mighty Maximin! (PDF File)
  This paper is dedicated to the modeling aspects of Maximin and robust optimization.


• Sniedovich, M. (2007) The art and science of modeling decision-making under severe uncertainty, Decision Making in Manufacturing and Services, 1-2, 111-136. (PDF File) .


• Sniedovich, M. (2007) Crystal-Clear Answers to Two FAQs about Info-Gap (PDF File)
  In this paper I examine the two fundamental flaws in Info-Gap decision theory, and the flawed attempts to shrug off my criticism of Info-Gap decision theory.


• My reply (PDF File) to Ben-Haim's response to one of my papers. (April 22, 2007)

  This is an exciting development!

  • Ben-Haim's response confirms my assessment of Info-Gap. It is clear that Info-Gap is fundamentally flawed and therefore unsuitable for decision-making under severe uncertainty.
  
  
  • Ben-Haim is not familiar with the fundamental concept point estimate. He does not realize that a function can be a point estimate of another function.

    So when you read my papers make sure that you do not misinterpret the notion point estimate. The phrase "A is a point estimate of B" simply means that A is an element of the same topological space that B belongs to. Thus, if B is say a probability density function and A is a point estimate of B, then A is a probability density function belonging to the same (assumed) set (family) of probability density functions.

    Ben-Haim mistakenly assumes that a point estimate is a point in a Euclidean space and therefore a point estimate cannot be say a function. This is incredible!



• A formal proof that Info-Gap is Wald's Maximin Principle in disguise. (December 31, 2006)
  This is a very short article entitled Eureka! Info-Gap is Worst Case (maximin) in Disguise! (PDF File)
  It shows that Info-Gap is not a new theory but rather a simple instance of Wald's famous Maximin Principle dating back to 1945, which in turn goes back to von Neumann's work on Maximin problems in the context of Game Theory (1928).


• A proof that Info-Gap's uncertainty model is fundamentally flawed. (December 31, 2006)
  This is a very short article entitled The Fundamental Flaw in Info-Gap's Uncertainty Model (PDF File) .
  It shows that because Info-Gap deploys a single point estimate under severe uncertainty, there is no reason to believe that the solutions it generates are likely to be robust.


• A math-free explanation of the flaw in Info-Gap. ( December 31, 2006)
  This is a very short article entitled The GAP in Info-Gap (PDF File) .
  It is a math-free version of the paper above. Read it if you are allergic to math.


• A long essay entitled What's Wrong with Info-Gap? An Operations Research Perspective (PDF File) (December 31, 2006).
  This is a paper that I presented at the ASOR Recent Advances in Operations Research (PDF File) mini-conference (December 1, 2006, Melbourne, Australia).

Recent Lectures, Seminars, Presentations

If your organization is promoting Info-Gap, I suggest that you invite me for a seminar at your place. I promise to deliver a lively, informative, entertaining and convincing presentation explaining why it is not a good idea to use — let alone promote — Info-Gap as a decision-making tool.

Here is a list of relevant lectures/seminars on this topic that I gave in the last two years.

• Black Swans, Modern Nostradamuses, Voodoo Decision Theories, and the Science of Decision-Making in the Face of Severe Uncertainty (PDF File) .
  (Invited tutorial, ALIO/INFORMS Conference, Buenos Aires, Argentina, July 6-9, 2010).


• A Critique of Info-Gap Decision theory: From Voodoo Decision-Making to Voodoo Economics(PDF File) .
  (Recent Advances in OR, RMIT, Melbourne, Australia, November 25, 2009)


• Robust decision-making in the face of severe uncertainty(PDF File) .
  (GRIPS, Tokyo, Japan, October 16, 2009)


• Decision-making in the face of severe uncertainty(PDF File) .
  (KORDS'09 Conference, Vilnius, Lithuania, September 30 -- OCtober 3, 2009)


• Modeling robustness against severe uncertainty (PDF File) .
  (SOR'09 Conference, Nova Gorica, Slovenia, September 23-25, 2009)


• How do you recognize a Voodoo decision theory?(PDF File) .
  (School of Mathematical and Geospatial Sciences, RMIT, June 26, 2009).


• Black Swans, Modern Nostradamuses, Voodoo Decision Theories, Info-Gaps, and the Science of Decision-Making in the Face of Severe Uncertainty (PDF File) .
  (Department of Econometrics and Business Statistics, Monash University, May 8, 2009).


• The Rise and Rise of Voodoo Decision Theory.
  ASOR Recent Advances, Deakin University, November 26, 2008. This presentation was based on the pages on my website (voodoo.moshe-online.com).


• Responsible Decision-Making in the face of Severe Uncertainty (PDF File) .
  (Singapore Management University, Singapore, September 29, 2008)


• A Critique of Info-Gap's Robustness Model (PDF File) .
  (ESREL/SRA 2008 Conference, Valencia, Spain, September 22-25, 2008)


• Robust Decision-Making in the Face of Severe Uncertainty (PDF File) .
  (Technion, Haifa, Israel, September 15, 2008)


• The Art and Science of Robust Decision-Making (PDF File) .
  (AIRO 2008 Conference, Ischia, Italy, September 8-11, 2008 )


• The Fundamental Flaws in Info-Gap Decision Theory (PDF File) .
  (CSIRO, Canberra, July 9, 2008 )


• Responsible Decision-Making in the Face of Severe Uncertainty (PDF File) .
  (OR Conference, ADFA, Canberra, July 7-8, 2008 )


• Responsible Decision-Making in the Face of Severe Uncertainty (PDF File) .
  (University of Sydney Seminar, May 16, 2008 )


• Decision-Making Under Severe Uncertainty: An Australian, Operational Research Perspective (PDF File) .
  (ASOR National Conference, Melbourne, December 3-5, 2007 )


• A Critique of Info-Gap (PDF File) .
  (SRA 2007 Conference, Hobart, August 20, 2007)


• What exactly is wrong with Info-Gap? A Decision Theoretic Perspective (PDF File) .
  (MS Colloquium, University of Melbourne, August 1, 2007)


• A Formal Look at Info-Gap Theory (PDF File) .
  (ORSUM Seminar , University of Melbourne, May 21, 2007)


• The Art and Science of Decision-Making Under Severe Uncertainty (PDF File) .
  (ACERA seminar, University of Melbourne, May 4, 2007)


• What exactly is Info-Gap? An OR perspective. (PDF File)
  ASOR Recent Advances in Operations Research mini-conference (December 1, 2006, Melbourne, Australia).

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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.

Last modified: Friday, 30-Jul-2010 23:25:29 MST