We establish a class of fully nonlinear conditional expectations. Similarly to the usage of linear expectations when a probabilistic description of uncertainty is present, we observe analogue quantitative and qualitative properties. The type of nonlinearity captures the agents sentiments of...

Following the real option literature, whether or not uncertainty shocks drive business cycles depends on the degree of adjustment frictions. The more plants freeze and remain inactive in response to increased uncertainty, the stronger the adverse effects on the economic activity. Using quarterly...

We investigate experimentally whether collective choice matters for individual attitudes to ambiguity. We consider a two-urn Ellsberg experiment: one urn offers a 45% chance of winning a fixed monetary prize, the other an ambiguous chance. Participants choose either individually or in groups of...

We study higher-order risk preferences, i.e. prudence and temperance, next to risk aversion in social settings. Previous experimental studies have shown that higher-order risk preferences affect the choices of individuals deciding privately on lotteries that only affect their own pay-off. Yet,...

Epstein and Schneider (2007) develop a framework of learning under ambiguity, generalizing maxmin preferences of Gilboa and Schmeidler (1989) to intertemporal settings. The specific belief dynamics in Epstein and Schneider (2007) rely on the rejection of initial priors that have become...

Most decisions concerning (self-)insurance and self-protection have to be taken in situations in which a) the effort exerted precedes the moment uncertainty realises, and b) the probabilities of future states of the world are not perfectly known. By integrating these two characteristics in a...

This paper provides a systematic analysis of individual attitudes towards ambiguity, based on laboratory experiments. The design of the analysis allows to capture individual behavior across various levels of ambiguity, ranging from low to high. Attitudes towards risk and attitudes towards...

We propose and axiomatically characterize a representation of ambiguity sensitive preferences. The distinguishing feature of our axiomatization is that we do not require preferences to be event-wise separable over any domain of acts. Even without any such separability restrictions, we are able...

The objective of our paper is to study R&D investments and pricing behavior in an environment with fundamental uncertainty. We designed a multi-period experiment in which each period consisted of two stages, an R&D phase and a pricing stage. Participants in the experiment had almost no...

Under risk, Arrow-Debreu equilibria can be implemented as Radner equilibria by continuous trading of few long-lived securities. We show that this result generically fails if there is Knightian uncertainty in the volatility. Implementation is only possible if all discounted net trades of the...