The precautionary principle (PP) applied to environmental policy stipulates that, in the presence of physical uncertainty, society must take robust preventive action to guard against worst-case outcomes. It follows that the higher the degree of uncertainty, the more aggressive this preventive...

Models can be wrong and recognising their limitations is important in financial and economic decision making under uncertainty. Robust strategies, which are least sensitive to perturbations of the underlying model, take uncertainty into account. Finding the explicit set of alternative models...

We study a notion of good-deal hedging, that corresponds to good-deal valuation and is described by a uniform supermartingale property for the tracking errors of hedging strategies. For generalized good-deal constraints, defined in terms of correspondences for the Girsanov kernels of pricing...

The paper offers a non-probabilistic framework for representation of uncertainty in the context of a simple linear-quadratic model of fiscal adjustment. Instead of treating model disturbances as random variables with known probability distributions, it is only assumed that they belong to some...

In a Ramsey policy regime, heterogeneity in beliefs about the potential costs of climate change is shown to produce policy ambiguities that alter carbon prices and taxation. Three sources of ambiguity are considered: (i) the private sector is skeptical, with beliefs that are unknown to the...

The prior paper in this sequel, Pope (2009) introduced the concept of a nominalist heuristic, defined as a focus on prominent numbers, indices or ratios. In this paper the concept is used to show three things in how scientists and practitioners analyse and evaluate to decide (conclude). First,...

Economic uncertainty has to do with the consequences of actions under different circumstances. This raises two questions: First, how sensitive are the outcomes of actions to variations in the environment? Second, how clearly can we distinguish between environments? Robustness comes at the price...

We axiomatize a new class of recursive dynamic models that capture subjective constraints on the amount of information a decision maker can obtain, pay attention to, or absorb, via a Markov Decision Process for Information Choice (MIC). An MIC is a subjective decision process that specifies what...

Uncertainty in economics is generated by “nature” but also by the model we use to “produce the future”. The production of the future comprises besides the allocation of resources on different instruments (technologies, financial products) also the design of the instruments....

One apparent reason for deferring a decision – abstaining from choosing, leaving the decision open to be taken by someone else, one’s later self, or nature – is for lack of sufficient confidence in the relevant beliefs. This paper develops an axiomatic theory of decision in situations...