Democratic reform and health : interpreting causal estimates

In The Lancet Global Health, Hannah Pieters and colleagues (September, 2016)1 analyse the effect of democratic reforms on child mortality across the world. We wish to highlight, however, that even with sophisticated causal inference techniques, such results cannot necessarily be interpreted as causal effects. First, the results are compatible with a number of different theories including that democratic reforms have no effect on health ceteris paribus (ie, holding everything else fixed). Consider the cases of South Africa, Zambia, Mozambique, and Zimbabwe, all notably missing from the analyses but experiencing substantial democratic changes, analysed here using a similar synthetic control analysis (figure).1, 2 No change is observed in South Africa after the end of apartheid in 1994. In Zambia, after reform in 1991, a reduction is observed but not until the price of copper tripled and GDP per capita doubled. In Mozambique, the large fall is likely attributable to the cessation of the civil war in 1993. And in Zimbabwe, democratic restrictions in 1987 did not precipitate an increase in child mortality

Yield differentials in treasury bills, 1959-64

Balance of payments ; Treasury bills ; Interest rates

Manufacturing flexible light-emitting polymer displays with conductive lithographic film technology

We report on a new low-cost manufacturing process for flexible displays that has the potential to rapidly expand the market into areas that have traditionally been outside the scope of such technology. In this paper we consider the feasibility of using offset-lithography to deposit contacts for polymer light-emitting displays. We compare and contrast manufacturing criteria and present a case study detailing our initial results. It is expected that these developments will stimulate further progress in multilayer device fabrication. Cheap, flexible conductive interconnects have the potential to find applications in a wide variety of device structures. For the more challenging exploitation areas in multilayer devices, such as displays, it was found that the properties of conductive lithographic films were not optimal in their current form. Three parameters (conductivity, surface roughness and surface work function) were identified as critical to device fabrication. Calendering and electroless plating were investigated as methods to improve these properties. Both methods aimed to modify the surface roughness and conductivity, with the plating study also modifying the work function

Ferroelectrically induced weak-ferromagnetism in a single-phase multiferroic by design

We present a strategy to design structures for which a polar lattice distortion induces weak ferromagnetism. We identify a large class of multiferroic oxides as potential realizations and use density-functional theory to screen several promising candidates. By elucidating the interplay between the polarization and the Dzyaloshinskii-Moriya vector, we show how the direction of the magnetization can be switched between 180$^{\circ}$ symmetry equivalent states with an applied electric field.Comment: Significantly revised for clarit