The unbiased expectations hypothesis states that forward rates are unbiased estimates for future short rates. Cox, Ingersoll and Ross [1] conjectured that this hypothesis should be inconsistent with the absence of arbitrage possibilities. Using the framework of Heath, Jarrow and Morton [4] we...

The effect of incomplete information on the term structure of interest rates is examined in the framework of a pure exchange economy under uncertainty. When the growth rate of the aggregate endowment is known, the term structure is flat and deterministic. When agents do not observe the...

We develop the fundamental theorem of asset pricing in a probability-free infinite-dimensional setup. We replace the usual assumption of a prior probability by a certain continuity property in the state variable. Probabilities enter then endogenously as full support martingale measures (instead...

Europäische Banken sind gesetzlich verpflichtet, bei ihren Geschäften strenge Regeln zur Risikoabwägung zu befolgen. Doch tatsächlich haben genau diese Regeln erst dazu geführt, dass die Finanzmärkte heiß liefen. Frank Riedel, Professor für Finanzmathematik, erklärt, wie es passieren...

We consider optimal stopping problems for ambiguity averse decision makers with multiple priors. In general, backward induction fails. If, however, the class of priors is time-consistent, we establish a generalization of the classical theory of optimal stopping. To this end, we develop first...

In infinite horizon economies only local equivalence of beliefs is needed to ensure the existence of an Arrow-Debreu equilibrium. In fact, agents can even disagree completely in the long run in the sense that asymptotically, their beliefs are singular. -- Heterogeneous expectations ;...