Strategic patents and asymmetric litigation costs as entry deterrence instruments

To spur innovation, the patent protection system grants the patentee limited monopoly power to recoup his R&D investment, although, in general, allowing the use of the public good "innovation" is socially efficient. But patents and patent threats can also be used strategically, e.g. to deter entry from competitors. This note shows that, besides incumbency, the present patent protection system constitutes an additional strategic instrument that favors the incumbent, because asymmetric litigation costs may deter entry from potential rivals.Entry deterrence

Microscopic description of fission in neutron-rich plutonium isotopes with the Gogny-D1M energy density functional

The most recent parametrization D1M of the Gogny energy density functional is used to describe fission in the isotopes $^{232-280}$ Pu. We resort to the methodology introduced in our previous studies [Phys. Rev. C \textbf{88}, 054325 (2013) and Phys. Rev. C \textbf {89}, 054310 (2014)] to compute the fission paths, collective masses and zero point quantum corrections within the Hartree-Fock-Bogoliubov framework. The systematics of the spontaneous fission half-lives t$_{SF}$, masses and charges of the fragments in Plutonium isotopes is analyzed and compared with available experimental data. We also pay attention to isomeric states, the deformation properties of the fragments as well as to the competition between the spontaneous fission and $\alpha$-decay modes. The impact of pairing correlations on the predicted t$_{SF}$ values is demonstrated with the help of calculations for $^{232-280}$Pu in which the pairing strengths of the Gogny-D1M energy density functional are modified by 5 $\%$ and 10 $\%$, respectively. We further validate the use of the D1M parametrization through the discussion of the half-lives in $^{242-262}$Fm. Our calculations corroborate that, though the uncertainties in the absolute values of physical observables are large, the Gogny-D1M Hartree-Fock-Bogoliubov framework still reproduces the trends with mass and/or neutron numbers and therefore represents a reasonable starting point to describe fission in heavy nuclear systems from a microscopic point of view.Comment: 14 pages, 11 figures. arXiv admin note: text overlap with arXiv:1312.722

Microscopic description of fission in nobelium isotopes with the Gogny-D1M energy density functional

Constrained mean-field calculations, based on the Gogny-D1M energy density functional, have been carried out to describe fission in the isotopes $^{250-260}$No. The even-even isotopes have been considered within the standard Hartree-Fock-Bogoliobov (HFB) framework while for the odd-mass ones the Equal Filling Approximation (HFB-EFA) has been employed. Ground state quantum numbers and deformations, pairing energies, one-neutron separation energies, inner and outer barrier heights as well as fission isomer excitation energies are given. Fission paths, collective masses and zero-point quantum vibrational and rotational corrections are used to compute the systematic of the spontaneous fission half-lives t$_\mathrm{SF}$ both for even-even and odd-mass nuclei. Though there exists a strong variance of the predicted fission rates with respect to the details involved in their computation, it is shown that both the specialization energy and the pairing quenching effects, taken into account within the self-consistent HFB-EFA blocking procedure, lead to larger t$_\mathrm{SF}$ values in odd-mass nuclei as compared with their even-even neighbors. Alpha decay lifetimes have also been computed using a parametrization of the Viola-Seaborg formula. The high quality of the Gogny-D1M functional regarding nuclear masses leads to a very good reproduction of $Q_{\alpha}$ values and consequently of lifetimes.Comment: 13 pages, 9 figure

Microscopic description of fission in Uranium isotopes with the Gogny energy density functional

The most recent parametrizations D1S, D1N and D1M of the Gogny energy density functional are used to describe fission in the isotopes $^{232-280}$ U. Fission paths, collective masses and zero point quantum corrections, obtained within the constrained Hartree-Fock-Bogoliubov approximation, are used to compute the systematics of the spontaneous fission half-lives $t_\mathrm{SF}$, the masses and charges of the fission fragments as well as their intrinsic shapes. The Gogny-D1M parametrization has been benchmarked against available experimental data on inner and second barrier heights, excitation energies of the fission isomers and half-lives in a selected set of Pu, Cm, Cf, Fm, No, Rf, Sg, Hs and Fl nuclei. It is concluded that D1M represents a reasonable starting point to describe fission in heavy and superheavy nuclei. Special attention is also paid to understand the uncertainties in the predicted $t_\mathrm{SF}$ values arising from the different building blocks entering the standard semi-classical Wentzel-Kramers-Brillouin formula. Although the uncertainties are large, the trend with mass or neutron numbers are well reproduced and therefore the theory still has predictive power. In this respect, it is also shown that modifications of a few per cent in the pairing strength can have a significant impact on the collective masses leading to uncertainties in the $t_\mathrm{SF}$ values of several orders of magnitude.Comment: 22 pages, 17 figures; Minor modifications to previous versio

Specialization in the bargaining family

We develop a two period family decision making model in which spouses bargain over their contributions to a family public good and the distribution of private consumption. In contrast to most models in the literature, specialization within the couple emerges endogenously from the production of the public good, and is not caused by exogenous differences between the spouses. Increasing marginal benefits of labour market experience make specialization efficient, even if both spouses have equal market and household productivities on the outset. If spouses are not able to enter into a binding contract governing the distribution of private consumption in the second period, the spouse specialized in market labour cannot commit to compensate the other spouse for foregone investments in earnings power. As a consequence, this spouse may withdraw part of his/her contribution and the provision level of the household good is likely to be inefficiently low.Family bargaining, specialization, private provision of public goods

The wage gap and the leisure gap for double earner couples

Empirical research has consistently shown that, on average, men are paid higher wages than women. At the same time, men enjoy more leisure time than women. We develop a model of private provision of family public goods to analyze whether the wage gap and the leisure gap are related. Within a nonco- operative framework, different bargaining power situations within a couple are considered which lead to different empirical hypotheses. With data from the German Socio-Economic Panel we focus on the leisure gap and the wage gap within double earner couples and in this way are able to discriminate among the theoretical models. Our random effects estimates show that husbands have a stronger bargaining position and this advantage results in them enjoying, other things equal, more leisure time that their wives.

Shape evolution and the role of intruder configurations in Hg isotopes within the interacting boson model based on a Gogny energy density functional

The interacting boson model with configuration mixing, with parameters derived from the self-consistent mean-field calculation employing the microscopic Gogny energy density functional, is applied to the systematic analysis of the low-lying structure in Hg isotopes. Excitation energies, electromagnetic transition rates, deformation properties, and ground-state properties of the $^{172-204}$Hg nuclei are obtained by mapping the microscopic deformation energy surface onto the equivalent IBM Hamiltonian in the boson condensate. These results point to the overall systematic trend of the transition from the near spherical vibrational state in lower-mass Hg nuclei close to $^{172}$Hg, onset of intruder prolate configuration as well as the manifest prolate-oblate shape coexistence around the mid-shell nucleus $^{184}$Hg, weakly oblate deformed structure beyond $^{190}$Hg up to the spherical vibrational structure toward the near semi-magic nucleus $^{204}$Hg, as observed experimentally. The quality of the present method in the description of the complex shape dynamics in Hg isotopes is examined.Comment: 19 pages, 14 figures, revised version including new results and discussions, title changed, accepted for publication in Phys. Rev.