Measurement Error, Legalized Abortion, and the Decline in Crime: A Response to Foote and Goetz (2005)

Donohue and Levitt (2001) argue that the legalization of abortion in the United States in the 1970s played an important role in explaining the observed decline in crime approximately two decades later. Foote and Goetz (2005) challenge the results presented in one of the tables in that original paper. In this reply, we regretfully acknowledge the omission of state-year interactions in the published version of that table, but show that their inclusion does not alter the qualitative results (or their statistical significance), although it does reduce the magnitude of the estimates. When one uses a more carefully constructed measure of abortion (e.g. one that takes into account cross-state mobility, or doing a better job of matching dates of birth to abortion exposure), however, the evidence in support of the abortion-crime hypothesis is as strong or stronger than suggested in our original work.

Further Evidence that Legalized Abortion Lowered Crime: A Reply to Joyce

Donohue and Levitt (2001) present a number of analyses that suggest a causal link between legalized abortion and reductions in crime almost two decades later when the cohorts exposed to legalized abortion reach their peak crime years. Joyce (2003) challenges that finding. In this paper, we demonstrate that Joyce's failure to uncover a negative relationship between abortion and crime is a direct consequence of his decision to focus exclusively on the six-year period 1985-90 without including adequate controls for the crack epidemic. We provide empirical evidence that crack hit the high-abortion early legalizing states harder and earlier. We then demonstrate that using precisely the same treatment and control groups as Joyce, but extending the data analysis to encompass the lifetime criminal experiences (as opposed to an arbitrary six-year window), the evidence strongly supports the hypothesis that legalized abortion reduces crime. We also show that our original results are robust to focusing on only the cohorts born immediately before or after Roe v. Wade. The data suggest that ease of access to abortion, rather than simply de jure legalization, is a critical determinant of the extent of the crime reduction.

Method and System for Creating Three-Dimensional Spatial Audio

A system and method for rendering a virtual sound source using a plurality of speakers in an arbitrary arrangement includes expanding a wave field of the virtual sound source and a composite wave field generated by the plurality of speakers into multi-pole expansions, and equating the multi-pole expansions to each other to form a continuous equation. A set of constraints is applied to the continuous equation that minimize an error in a sweet spot region resulting in a linear system of equations. The linear system of equations is solved using singular-value decomposition to arrive at a pseudo-inverse representing a multi-dimensional transfer function between the virtual sound source and the plurality of speakers. The multi-dimensional transfer function is then applied to a signal of the virtual sound source to render the virtual sound source in the sweet spot region using the plurality of speakers in the arbitrary arrangement

Axial anomaly and magnetism of nuclear and quark matter

We consider the response of the QCD ground state at finite baryon density to a strong magnetic field B. We point out the dominant role played by the coupling of neutral Goldstone bosons, such as pi^0, to the magnetic field via the axial triangle anomaly. We show that, in vacuum, above a value of B ~ m_pi^2/e, a metastable object appears - the pi^0 domain wall. Because of the axial anomaly, the wall carries a baryon number surface density proportional to B. As a result, for B ~ 10^{19} G a stack of parallel pi^0 domain walls is energetically more favorable than nuclear matter at the same density. Similarly, at higher densities, somewhat weaker magnetic fields of order B ~ 10^{17}-10^{18} G transform the color-superconducting ground state of QCD into new phases containing stacks of axial isoscalar (eta or eta') domain walls. We also show that a quark-matter state known as ``Goldstone current state,'' in which a gradient of a Goldstone field is spontaneously generated, is ferromagnetic due to the axial anomaly. We estimate the size of the fields created by such a state in a typical neutron star to be of order 10^{14}-10^{15} G.Comment: 18 pages, v2: added a discussion of the energy cost of neutralizing the domain wall charg

A Two-Dimensional, Self-Consistent Model of Galactic Cosmic Rays in the Heliosphere

We present initial results from our new two-dimensional (radius and latitude), self-consistent model of galactic cosmic rays in the heliosphere. We focus on the latitudinal variations in the solar wind flow caused by the energetic particles. Among other things our results show that the cosmic rays significantly modify the latitudinal structure of the solar wind flow downstream of the termination shock. Specifically, for A>0 (corresponding to the present solar minimum) the wind beyond the shock is driven towards the equator, resulting in a faster wind flow near the current sheet, while for A<0 the effect is reversed and the wind turns towards the pole, with a faster flow at high latitudes. We attribute this effect to the latitudinal gradients in the cosmic ray pressure, caused by drifts, that squeeze the flow towards the ecliptic plane or the pole, respectively.Comment: 10 pages, 4 Postscript figures, uses AAS LaTeX v4.0, to be published in The Astrophysical Journal Letter

High-pressure study on the superconducting pyrochlore oxide Cd2Re2O7

Superconducting and structural phase transitions in a pyrochlore oxide Cd2Re2O7 are studied under high pressure by x-ray diffraction and electrical resistivity measurements. A rich P-T phase diagram is obtained, which contains at least two phases with the ideal and slightly distorted pyrochlore structures. It is found that the transition between them is suppressed with increasing pressure and finally disappears at a critical pressure Pc = 3.5 GPa. Remarkable enhancements in the residual resistivity as well as the coefficient A of the AT 2 term in the resistivity are found around the critical pressure. Superconductivity is detected only for the phase with the structural distortion. It is suggested that the charge fluctuations of Re ions play a crucial role in determining the electronic properties of Cd2Re2O7.Comment: 5 pages, 5 figures, submitted to J. Phys. Soc. Jp

Health system constraints to optimal coverage of the prevention of mother-to-child HIV transmission programme in South Africa: lessons from the implementation of the national pilot programme

Background: It is three years since the government of South Africa began implementing a PMTCT programme. Over this period of time attempts have been made to scale up this programme across all provinces under routine health service conditions. Objectives: To report on the uptake and performance of South Africa\'s national pilot programme for preventing mother to child HIV transmission (PMTCT) and to identify health system constraints to optimal coverage. Methods: Routine programme data were collected from antenatal records and delivery registers at the pilot sites and interviews were conducted with health workers on site and with provincial programme managers. Results: Routine PMTCT programme data were collected from all 18 pilot sites for the period January to December 2002. During this period, of 84406 women attending the sites for first antenatal visits, 47267 (56%) agreed to an HIV test. 14340 (30%) of the women tested were HIV positive and of these 7853 (55%) were dispensed nevirapine. 7950 (99%) of infants born to women identified as being HIV positive received nevirapine syrup. 58% (4196/7237) of HIV positive women expressed an intention to exclusively formula feed, and 42% (3041/7237) intended to exclusively breastfeed. 1907 infants were due for 12 month HIV testing between January and December 2002, of these 949 (50%) infants were tested. Conclusions: Programme effectiveness was limited by the low rate of HIV test acceptance, poor delivery of nevirapine to mothers and inability to track mother-infant pairs postnatally for 12-month HIV testing of infants. Infant feeding intentions of mothers suggest inadequate counselling and possible negative effects of the provision of free formula milk. The poor perfor- mance of the main components of this programme will seriously reduce its operational effectiveness. There is a need for greater integration of VCT within antenatal care, a review of the current policy of providing free formula milk and an alternative model for mother-infant follow up. African Health Sciences Vol. 5 (3) 2005: pp. 213-21

Aerothermodynamic radiation studies

We have built and made operational a 6 in. electric arc driven shock tube which alloys us to study the non-equilibrium radiation and kinetics of low pressure (0.1 to 1 torr) gases processed by 6 to 12 km/s shock waves. The diagnostic system allows simultaneous monitoring of shock radiation temporal histories by a bank of up to six radiometers, and spectral histories with two optical multi-channel analyzers. A data set of eight shots was assembled, comprising shocks in N2 and air at pressures between 0.1 and 1 torr and velocities of 6 to 12 km/s. Spectrally resolved data was taken in both the non-equilibrium and equilibrium shock regions on all shots. The present data appear to be the first spectrally resolved shock radiation measurements in N2 performed at 12 km/s. The data base was partially analyzed with salient features identified