What is the difference between “robust-optimal” and “robust-satisficing” decisions in the framework of Info-Gap decision theory?
Answer-34: Insignificant! The difference is basically in the jargon. Thus, in the first edition of the book (Ben-Haim 2001) the term “robust optimal” designates the optimal decision selected by Info-Gap’s decision-making model. For example, on p. 76 the optimal investment generated by Info-Gap’s decision-making model for the portfolio investment problem studied there is dubbed “Robust-Optimal Investment”. The same investment is dubbed “Robust-satisficing Investment” in the second edition (Ben-Haim 2006, p. 71). Interestingly, though, despite this deliberate shift in the jargon, some remnants of “Robust-Optimal” from the first edition can still be found in the second edition of the book, eg. Bem-Haim (2006, p. 182). Before I proceed to explain whence this shift in jargon, I need to point out that the term “Robust-satisficing” indicates robustness that is sought with respect to a “constraint” rather than an “objective function”. The shift from “Robust-Optimal” to “Robust-satisficing” is
