There exist several characterizations of concavity for univariate functions. One of them states that a function is concave if and only if it has nonincreasing differences. This definition provides a natural generalization of concavity for multivariate functions called inframodularity....

This paper focuses on information acquisition and individual decision making in ambiguous situations and presents a novel experimental design which may help to tackle open questions from a fresh perspective. Instead of giving subjects the choice between risky and ambiguous Ellsberg urns, we let...

There are two phenomena in behavioral finance and economics which are seemingly unrelated and have been studied separately; overconfidence and ambiguity aversion. In this paper we are trying to link these two phenomena providing a theoretical foundation supported by evidence from an experimental...

This paper reports experiments conducted to test whether ambiguity affects individual behaviour in games of strategic complements and strategic substitutes. We study subject behaviour in the presence of ambiguity in order to ascertain whether subjects' perception of ambiguity differs between a...

Observed individual behavior in the presence of ambiguity is characterized by insufficient responsiveness to changes in subjective likelihoods. Such likelihood insensitivity under ambiguity is integral to theoretical models and predictive of behavior in many important domains such as financial...

The classic choice-theoretic construction of subjective probability (Savage, 1954) does not apply to preferences, like those in the Ellsberg Paradox, that reflect a distinction between risk and ambiguity. We formulate two representation results – one for expected utility, the other for...

Recent research on real options does not only consider optimal investment decisions under risk, but also under ambiguity. However, most models that allow for ambiguity are generally not dynamically consistent. Examples are, among others, the $\alpha$-MEU model, the imprecision aversion model, or...

This paper studies the relation between concavity, stochastic or state dependent utility functions, and risk aversion. Using the common definition of risk aversion, but modified for state dependent preferences, we show that concavity does not imply risk aversion. Instead, it implies a weaker...