It is shown that, in a semimartingale financial market model, there is equivalence between absence of arbitrage of the first kind (a weak viability condition) and the existence of a strictly positive process that acts as a local martingale deflator on nonnegative wealth processes. Copyright...

We review the main results in the theory of quadratic hedging in a general incomplete model of continuous trading with semimartingale price process. The objective is to hedge contingent claims by using portfolio strategies. We describe two types of criteria: the so-called (local)...

This paper provides limit distribution results for power variation, that is sums of powers of absolute increments, for certain types of time-changed Brownian motion and $alpha $-stable processes. Special cases of these processes are stochastic volatility models used extensively in financial...

The publication of a projected path of future policy decisions by central banks is a controversially debated method to improve monetary policy guidance. This paper suggests a new approach to evaluate the impact of the guidance strategy on the predictability of monetary policy. Using the example...