2,773 research outputs found
CAPM, rewards, and empirical asset pricing with coherent risk
The paper has 2 main goals: 1. We propose a variant of the CAPM based on
coherent risk. 2. In addition to the real-world measure and the risk-neutral
measure, we propose the third one: the extreme measure. The introduction of
this measure provides a powerful tool for investigating the relation between
the first two measures. In particular, this gives us - a new way of measuring
reward; - a new approach to the empirical asset pricing
Dilute Bose gas: short-range particle correlations and ultraviolet divergence
The modified Bogoliubov model where the primordial interaction is replaced by
the t matrix is reinvestigated. It is shown to provide a negative value of the
kinetic energy for a strongly interacting dilute Bose gas, contrary to the
original Bogoliubov model. To clear up the origin of this failure, the correct
values of the kinetic and interaction energies of a dilute Bose gas are
calculated. It is demonstrated that both the problem of the negative kinetic
energy and the ultraviolet divergence, dating back to the well-known paper of
Lee, Yang and Huang, is connected with an inadequate picture of the short-range
boson correlations. These correlations are reconsidered within the
thermodynamically consistent model proposed earlier by the present authors.
Found results are in absolute agreement with the data of the Monte-Carlo
calculations for the hard-sphere Bose gas.Comment: 11 pages, REVTeX, 2 figures inserte
Coherent measurement of factor risks
We propose a new procedure for the risk measurement of large portfolios. It
employs the following objects as the building blocks: - coherent risk measures
introduced by Artzner, Delbaen, Eber, and Heath; - factor risk measures
introduced in this paper, which assess the risks driven by particular factors
like the price of oil, S&P500 index, or the credit spread; - risk contributions
and factor risk contributions, which provide a coherent alternative to the
sensitivity coefficients.
We also propose two particular classes of coherent risk measures called Alpha
V@R and Beta V@R, for which all the objects described above admit an extremely
simple empirical estimation procedure. This procedure uses no model assumptions
on the structure of the price evolution.
Moreover, we consider the problem of the risk management on a firm's level.
It is shown that if the risk limits are imposed on the risk contributions of
the desks to the overall risk of the firm (rather than on their outstanding
risks) and the desks are allowed to trade these limits within a firm, then the
desks automatically find the globally optimal portfolio
Reforming the over-the-counter derivatives market: what’s to be gained?
While derivative financial instruments have made the hedging and exchange of risk more efficient, the recent crisis showed that they also pose a substantial threat to financial stability in times of systemic turmoil. Underlying much of this threat is the lack of transparent reporting in the over-the-counter market for these instruments. This Commentary discusses the advantages of one solution to the transparency proble: moving the settlement or trading of derivatives to exchanges or clearinghouses.Derivative securities ; Financial market regulatory reform ; Over-the-counter markets
- …