Decision Making Under Deep Uncertainty often uses prohibitively large scenario ensembles to calculate robustness and rank policies’ performance. This paper contributes a framework using subsampling ...algorithms and space-filling metrics to determine how smaller ensemble sizes impact the accuracy of robustness rankings. Subsampling methods create smaller scenario ensembles of varying sizes. We evaluate ranking sensitivity to the ensemble size and calculate accuracy relative to a baseline ranking. Then, metrics of scenario set quality predict ranking accuracy. Notably, the metrics and subsampling methods do not require additional model simulations. We demonstrate the framework with a case study of shortage policies for Lake Mead in the Colorado River Basin (CRB). Results suggest that fewer scenarios than previous studies can accurately rank Lake Mead policies, and results depend on the type of objective and robustness metric. Smaller ensembles could reduce the computational burden of robustness analyses in the ongoing CRB policy renegotiation.
•Framework tests sensitivity of policy robustness rankings to scenario ensemble size.•Subsampling methods reevaluate policy rankings without additional simulations.•Model-free metrics of scenario ensemble quality predict rank accuracy.•Case study: shortage operation policies of Lake Mead in the Colorado River Basin.•Fewer scenarios than previous studies can accurately rank Lake Mead policies.
A natural problem in the methodology of Economics is how to model interactions in which the decisions made by agents depend on the beliefs held about both objective aspects of the relevant situation ...and the beliefs ascribed to other agents. There are two ways of representing such contexts. One is by means of a hierarchy of beliefs, the other as a state of the world. These two can be seen, from a Systems-theoretical perspective, as representing streams generated by a process and its fixed points, respectively. These two representations are in fact equivalent. The finer question we address here is whether they are identical. Resorting to a type-theoretical syntax, we obtain a unified interpretation in which both entities give rise to
-groupoids. Voevodsky's univalent axiom then ensures their identity in small types universes.
Coarse contingencies and ambiguity Epstein, Larry G; Marinacci, Massimo; Seo, Kyoungwon
Theoretical economics,
12/2007, Volume:
2, Issue:
4
Journal Article
Peer reviewed
Open access
The paper considers an agent who must choose an action today under uncertainty about the consequence of any chosen action but without having in mind a complete list of all the contingencies that ...could in‡fluence outcomes. She conceives of some relevant (subjective) contingencies but she is aware that these contingencies are coarse---they leave out some details that may affect outcomes. Though she may not be able to describe these finer details, she is aware that they exist and this may affect her behavior.
This paper develops an axiomatic theory of decision-making under uncertainty that dispenses with the state-space. The results are subjective expected utility models with unique, action-dependent, ...subjective probabilities, and a utility function defined over wealth-effect pairs that is unique up to a positive linear transformation.
We present here a notion of state of the world general enough to embrace most circular phenomena in economics and game theory. We prove that it obtains by unfolding beliefs only if the process of ...belief generation has a fixed point. Otherwise, we are led to an unending transfinite hierarchy. This result indicates that Zermelo–Frenkel's set theory cannot provide the modeling tools for the representation of states of the world. We apply, instead, a theory of non-well-founded sets. In that framework, states of the world are legitimate objects which can be seen as fixed points of the belief-generation operator.
Not every possible state of the world can be unfolded in a hierarchy of beliefs. It will be shown by means of a simple argument, based in Tarski's indefinability theorem, that there exist states of the world that are not expressible in that way. Moreover, this result implies that there is no way to represent those states of the world in a consistent language. However, if we assume agents do not have negative self-referential beliefs, the unfolding of beliefs suffices.
A new set of metaphysical arguments in favour of fundamental reality is proposed in the article. For this purpose the notion of the state of the world is introduced. The standard concept of grounding ...underlying metaphysical foundationalism is taken into account. The correspondence of the new notion and the initial principles of metaphysical fundamentalism are confirmed. The proof of fundamental reality existence is represented based on formulated principles and empirical data.
Exceptionally not grounded on the rhetorical penetration of the great theoretical schemes of international relations and foreign policy areas of academic knowledge but grounded, instead, on the ...juxtaposition of the new Obama Administration's main electoral promises on foreign policy related matters with a series of empirical data on the current state of the world, the aim of these remarks is that of providing the reader with a down-to-Earth introductory background to the future of US' foreign policy. --- Excepcionalmente no basado en la penetración retórica de los grandes esquemas teóricos de las áreas de conocimiento académico de las relaciones internacionales y la política exterior, sino en la mera yuxtaposición de las principales promesas electorales de la nueva Administración Obama con una serie de datos empíricos sobre el estado del mundo, la intención que anima estos apuntes es la de proporcionar al lector un trasfondo introductorio realista al futuro de la política exterior estadounidense.
A new set of metaphysical arguments in favour of fundamental reality is proposed in the article. For this purpose the notion of the state of the world is introduced. The standard concept of grounding ...underlying metaphysical foundationalism is taken into account. The correspondence of the new notion and the initial principles of metaphysical fundamentalism are confirmed. The proof of fundamental reality existence is represented based on formulated principles and empirical data.
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