Minimum Guaranteed Payments and Costly Cancellation Rights: A Stopping Game Perspective

We consider the valuation and optimal exercise policy of a δ- penalty minimum guaranteed payment option in the case where the value of the underlying dividend-paying asset follows a linear diffusion. We characterize both the value and optimal exercise policy of the considered game option explicitly and demonstrate that increased volatility increases the value of the option and postpones exercise by expanding the continuation region where exercising is suboptimal. An interesting and natural implication of this finding is that the value of the embedded cancellation rights of the issuer increase as volatility increases.minimum guaranteed payment, δ-penalty options, Dynkin games, linear diffusions

Gamow-Teller strength distributions in Fe and Ni stable isotopes

We study Gamow-Teller strength distributions in some selected nuclei of particular Astrophysical interest within the iron mass region. The theoretical framework is based on a proton-neutron Quasiparticle Random Phase Approximation built on a deformed selfconsistent mean field basis obtained from two-body density-dependent Skyrme forces. We compare our results to available experimental information obtained from (n,p) and (p,n) charge exchange reactions.Comment: 11 pages, 3 figure

Isospin mixing and Fermi transitions: Selfconsistent deformed mean field calculations and beyond

We study Fermi transitions and isospin mixing in an isotopic chain 70-78 Kr considering various approximations that use the same Skyrme-Hartree-Fock single particle basis. We study Coulomb effects as well as the effect of BCS and quasiparticle random phase approximation (QRPA) correlations. A measure of isospin mixing in the approximate ground state is defined by means of the expectation value of the isospin operator squared in N=Z nuclei (which is generalized to N different from Z nuclei). Starting from strict Hartree-Fock approach without Coulomb, it is shown that the isospin breaking is negligible, on the order of a few per thousand for (N-Z)=6, increasing to a few percent with Coulomb. Pairing correlations induce rather large isospin mixing and Fermi transitions of the forbidden type (beta- for NZ). The enhancement produced by BCS correlations is compensated to a large extent by QRPA correlations induced by isospin conserving residual interactions that tend to restore isospin symmetry.Comment: 14 pages, 5 figures, to be published in Phys. Rev.

Whose absentee votes are returned and counted: The variety and use of absentee ballots in California

Absentee voting is becoming more prevalent throughout the United States. Although there has been some research focused on who votes by absentee ballot, little research has considered another important question about absentee voting: which absentee ballots are counted and which are not? Research in the wake of the 2000 presidential election has studied the problem of uncounted ballots for precinct voters but not for absentee voters. Using data from Los Angeles County – nation's largest and most diverse voting jurisdiction – for the November 2002 general election, we test a series of hypotheses that certain types of voters have a higher likelihood that their ballots will be counted. We find that uniform service personnel, overseas civilians, voters who request non-English ballots and permanent absentee voters have a much lower likelihood of returning their ballot, and once returned, a lower likelihood that their ballots will be counted compared with the general absentee voting population. We also find that there is little partisan effect as to which voters are more likely to return their ballots or have their ballots counted. We conclude our paper with a discussion of the implications of our research for the current debates about absentee voting