ABSTRACT We show that cross-border financial linkages are priced in CDS markets. We construct a m... more ABSTRACT We show that cross-border financial linkages are priced in CDS markets. We construct a measure of the foreign exposure risk of a country's banking system based on the composition of its foreign exposures. Our measure helps explain CDS premia of banks. Implicit and explicit guarantees extended to a country's banking system in turn affect the CDS premia of the sovereign. As a consequence, foreign exposures of banks impact the dynamics of sovereign CDS spreads. Another measure including both foreign and domestic assets of the banks is highly signicant in explaining bank CDS spreads even before the onset of the crisis.
ABSTRACT We develop a theory for a general class of discrete-time stochastic control problems tha... more ABSTRACT We develop a theory for a general class of discrete-time stochastic control problems that, in various ways, are time-inconsistent in the sense that they do not admit a Bellman optimality principle. We attack these problems by viewing them within a game theoretic framework, and we look for subgame perfect Nash equilibrium points. For a general controlled Markov process and a fairly general objective functional, we derive an extension of the standard Bellman equation, in the form of a system of nonlinear equations, for the determination of the equilibrium strategy as well as the equilibrium value function. Most known examples of time-inconsistent stochastic control problems in the literature are easily seen to be special cases of the present theory. We also prove that for every time-inconsistent problem, there exists an associated time-consistent problem such that the optimal control and the optimal value function for the consistent problem coincide with the equilibrium control and value function, respectively for the time-inconsistent problem. To exemplify the theory, we study some concrete examples, such as hyperbolic discounting and mean-variance control.
We price vulnerable derivatives – i.e. derivatives where the counterparty may default. These are ... more We price vulnerable derivatives – i.e. derivatives where the counterparty may default. These are basically the derivatives traded on the over-the-counter (OTC) markets. Default is modelled in a structural framework. The technique employed for pricing is good deal bounds (GDBs). The method imposes a new restriction in the arbitrage free model by setting upper bounds on the Sharpe ratios (SRs) of the assets. The potential prices that are eliminated represent unreasonably good deals. The constraint on the SR translates into a constraint on the stochastic discount factor. Thus, tight pricing bounds can be obtained. We provide a link between the objective probability measure and the range of potential risk-neutral measures, which has an intuitive economic meaning. We also provide tight pricing bounds for European calls and show how to extend the call formula to pricing other financial products in a consistent way. Finally, we numerically analyse the behaviour of the good deal pricing bounds.
ABSTRACT We show that cross-border financial linkages are priced in CDS markets. We construct a m... more ABSTRACT We show that cross-border financial linkages are priced in CDS markets. We construct a measure of the foreign exposure risk of a country's banking system based on the composition of its foreign exposures. Our measure helps explain CDS premia of banks. Implicit and explicit guarantees extended to a country's banking system in turn affect the CDS premia of the sovereign. As a consequence, foreign exposures of banks impact the dynamics of sovereign CDS spreads. Another measure including both foreign and domestic assets of the banks is highly signicant in explaining bank CDS spreads even before the onset of the crisis.
ABSTRACT We develop a theory for a general class of discrete-time stochastic control problems tha... more ABSTRACT We develop a theory for a general class of discrete-time stochastic control problems that, in various ways, are time-inconsistent in the sense that they do not admit a Bellman optimality principle. We attack these problems by viewing them within a game theoretic framework, and we look for subgame perfect Nash equilibrium points. For a general controlled Markov process and a fairly general objective functional, we derive an extension of the standard Bellman equation, in the form of a system of nonlinear equations, for the determination of the equilibrium strategy as well as the equilibrium value function. Most known examples of time-inconsistent stochastic control problems in the literature are easily seen to be special cases of the present theory. We also prove that for every time-inconsistent problem, there exists an associated time-consistent problem such that the optimal control and the optimal value function for the consistent problem coincide with the equilibrium control and value function, respectively for the time-inconsistent problem. To exemplify the theory, we study some concrete examples, such as hyperbolic discounting and mean-variance control.
We price vulnerable derivatives – i.e. derivatives where the counterparty may default. These are ... more We price vulnerable derivatives – i.e. derivatives where the counterparty may default. These are basically the derivatives traded on the over-the-counter (OTC) markets. Default is modelled in a structural framework. The technique employed for pricing is good deal bounds (GDBs). The method imposes a new restriction in the arbitrage free model by setting upper bounds on the Sharpe ratios (SRs) of the assets. The potential prices that are eliminated represent unreasonably good deals. The constraint on the SR translates into a constraint on the stochastic discount factor. Thus, tight pricing bounds can be obtained. We provide a link between the objective probability measure and the range of potential risk-neutral measures, which has an intuitive economic meaning. We also provide tight pricing bounds for European calls and show how to extend the call formula to pricing other financial products in a consistent way. Finally, we numerically analyse the behaviour of the good deal pricing bounds.
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Papers by Agatha Murgoci