44,900 research outputs found
Trading-Off Reproductive Technology and Adoption: Does Subsidizing in Vitro Fertilization Decrease Adoption Rates and Should It Matter?
For those facing infertility, using assisted reproductive technology to have genetically related children is a very expensive proposition. In particular, to produce a live birth through in vitro fertilization (IVF) will cost an individual (on average) between 114,286 in the U.S. If forced to pay these prices out of pocket, many would be unable to afford this technology. Given this reality, a number of states have attempted to improve access to reproductive technology through state-level insurance mandates that cover IVF. Several scholars, however, have worried that increasing access in this way will cause a diminution in adoptions and have argued against enactment of state mandates for that reason. In this paper, which was selected for presentation at the 2010 Stanford-Yale Junior Faculty Forum, we push against that conclusion on two fronts. First, we interrogate the normative premises of the argument and expose its contestable implicit assumptions about how the state should balance the interests of existing children waiting for adoption and those seeking access to reproductive technology in order to have genetically related children. Second, we investigate the unexamined empirical question behind the conclusion: does state subsidization of reproductive technologies through insurance mandates actually reduce adoption; that is, is there a trade-off between helping individuals conceive and helping children waiting to be adopted? We call the claim that there is such an effect the “substitution theory.” Using the differential timing of introduction of state-level insurance mandates relating to IVF in some states and differences in the forms these mandates take, we employ several different econometric techniques (differences-in-differences, ordinary least squares, two-stage least squares) to examine the effect of these mandates on IVF utilization and adoption. Contrary to the assumption of the substitution theory, we find no strong evidence that state support of IVF through these mandates crowds out either domestic or international adoption.
Appendix A re-analyses our results using the insurance mandate categorization of other studies in the literature
First-principles thermoelasticity of bcc iron under pressure
We investigate the elastic and isotropic aggregate properties of
ferromagnetic bcc iron as a function of temperature and pressure by computing
the Helmholtz free energies for the volume-conserving strained structures using
the first-principles linear response linear-muffin-tin-orbital method and the
generalized-gradient approximation. We include the electronic excitation
contributions to the free energy from the band structures, and phonon
contributions from quasi-harmonic lattice dynamics. We make detailed
comparisons between our calculated elastic moduli and their temperature and
pressure dependences with available experimental and theoretical data.Comment: 5 figures, 2 table
Level Splitting in Association with the Multiphoton Bloch-Siegert Shift
We present a unitary equivalent spin-boson Hamiltonian in which terms can be
identified which contribute to the Bloch-Siegert shift, and to the level
splittings at the anticrossings associated with the Bloch-Siegert resonances.
First-order degenerate perturbation theory is used to develop approximate
results in the case of moderate coupling for the level splitting.Comment: 8 pages, 2 figure
Front Propagation up a Reaction Rate Gradient
We expand on a previous study of fronts in finite particle number
reaction-diffusion systems in the presence of a reaction rate gradient in the
direction of the front motion. We study the system via reaction-diffusion
equations, using the expedient of a cutoff in the reaction rate below some
critical density to capture the essential role of fl uctuations in the system.
For large density, the velocity is large, which allows for an approximate
analytic treatment. We derive an analytic approximation for the front velocity
depe ndence on bulk particle density, showing that the velocity indeed diverge
s in the infinite density limit. The form in which diffusion is impleme nted,
namely nearest-neighbor hopping on a lattice, is seen to have an essential
impact on the nature of the divergence
Time-dependent single electron tunneling through a shuttling nano-island
We offer a general approach to calculation of single-electron tunneling
spectra and conductance of a shuttle oscillating between two half-metallic
leads with fully spin polarized carriers. In this case the spin-flip processes
are completely suppressed and the problem may be solved by means of canonical
transformation, where the adiabatic component of the tunnel transparency is
found exactly, whereas the non-adiabatic corrections can be taken into account
perturbatively. Time-dependent corrections to the tunnel conductance of moving
shuttle become noticeable at finite bias in the vicinity of the even/odd
occupation boundary at the Coulomb diamond diagram.Comment: 12 pages, 4 figure
Multiphoton Bloch-Siegert shifts and level-splittings in spin-one systems
We consider a spin-boson model in which a spin 1 system is coupled to an
oscillator. A unitary transformation is applied which allows a separation of
terms responsible for the Bloch-Siegert shift, and terms responsible for the
level splittings at anticrossings associated with Bloch-Siegert resonances.
When the oscillator is highly excited, the system can maintain resonance for
sequential multiphoton transitions. At lower levels of excitation, resonance
cannot be maintained because energy exchange with the oscillator changes the
level shift. An estimate for the critical excitation level of the oscillator is
developed.Comment: 14 pages, 3 figure
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