Maori/Non-Maori Income Gaps: Do Differences in Worker Mobility Play a Role?

We estimate a model of net migration between Regional Councils for three age cohorts to test whether or not there are significant Maori/non-Maori differences. We find little evidence of a statistically significant link between worker mobility and labor market conditions. Only in the case of the youngest individuals (20-24 years of age) do we find a significant wage response, and this wage response does not differ significantly between Maori and non-Maori. Unemployment is no case found to be significantly related to migration. We conclude from this that differences in worker mobility and attendant differences in the propensity to take advantage of spatially dispersed economic opportunities has limited potential for explaining Maori/non-Maori income differentials.Labor and Human Capital, J61, R11,

RURAL INFRASTRUCTURE, TRANSACTIONS COSTS, AND MARKETED SURPLUS IN KENYA

We develop a conceptual framework for quantifying fixed transactions costs facing semisubsistence households. Using household survey data from a sample of 324 Kenyan maize farmers, we generate estimates of household supply and demand schedules, as well as the price bands that they face. Our econometric results indicate that on average the ad valorem tax equivalent of the fixed transactions costs facing the households in our sample is 28%. Additional analysis indicates that both remoteness and infrastructure quality have significant impacts on the size of the transactions costs facing farm households. To the best of our knowledge, ours are the first empirical estimates of the magnitude of transactions costs.Marketing,

Phonon spectral function for an interacting electron-phonon system

Using exact diagonalzation techniques, we study a model of interacting electrons and phonons. The spectral width of the phonons is found to be reduced as the Coulomb interaction U is increased. For a system with two modes per site, we find a transfer of coupling strength from the upper to the lower mode. This transfer is reduced as U is increased. These results give a qualitative explanation of differences between Raman and photoemission estimates of the electron-phonon coupling constants for A3C60 (A= K, Rb).Comment: 4 pages, RevTeX, 2 eps figur

Frog in the Pan: Continuous Information and Momentum

We test a frog-in-the-pan (FIP) hypothesis that predicts investors are inattentive to information arriving continuously in small amounts. Intuitively, we hypothesize that a series of frequent gradual changes attracts less attention than infrequent dramatic changes. Consistent with the FIP hypothesis, we find that continuous information induces strong persistent return continuation that does not reverse in the long run. Momentum decreases monotonically from 5.94% for stocks with continuous information during their formation period to –2.07% for stocks with discrete information but similar cumulative formation-period returns. Higher media coverage coincides with discrete information and mitigates the stronger momentum following continuous information

BuFF: Burst Feature Finder for Light-Constrained 3D Reconstruction

Robots operating at night using conventional vision cameras face significant challenges in reconstruction due to noise-limited images. Previous work has demonstrated that burst-imaging techniques can be used to partially overcome this issue. In this paper, we develop a novel feature detector that operates directly on image bursts that enhances vision-based reconstruction under extremely low-light conditions. Our approach finds keypoints with well-defined scale and apparent motion within each burst by jointly searching in a multi-scale and multi-motion space. Because we describe these features at a stage where the images have higher signal-to-noise ratio, the detected features are more accurate than the state-of-the-art on conventional noisy images and burst-merged images and exhibit high precision, recall, and matching performance. We show improved feature performance and camera pose estimates and demonstrate improved structure-from-motion performance using our feature detector in challenging light-constrained scenes. Our feature finder provides a significant step towards robots operating in low-light scenarios and applications including night-time operations.Comment: 7 pages, 9 figures, 2 tables, for associated project page, see https://roboticimaging.org/Projects/BuFF

Investment in a Smaller World: The Implications of Air Travel for Investors and Firms

A large literature reports that proximity influences investment. We extend the measurement of proximity beyond distance and report that air travel reduces local investment bias. This result is confirmed using the initiation of connecting flights through recently opened air hubs because investment at destinations served by these connecting flights increases after, not before, their initiation. Air travel also broadens the investor base of firms and lowers their cost of equity by approximately 1%. Overall, air travel improves the diversification of investor portfolios and lowers the cost of equity for firms

Factory Flow Benchmarking Report

The Lean Aircraft Initiative benchmarked representative part fabrications and some assembly operations within its member companies of the defense aircraft industry. This paper reports the results of this benchmarking effort. Comparisons are made using an efficiency metric called flow efficiency. Flow efficiency is defined as the ratio of the fabrication time to the cycle time. In addition, this report explores the major components of the cycle time: fabrication time, lot process delay, storage delay, and transportation delay. The report concludes that the major portion of the cycle time in this industry is storage delay and points out the opportunity to improve cycle time drastically by reducing the amount of storage delay being experienced in the fabrication of products

Effect of tibolone on breast cancer cell proliferation in postmenopausal ER+ patients: Results from STEM trial

Purpose: Tibolone is a selective tissue estrogenic activity regulator, approved for the treatment of vasomotor symptoms in postmenopausal women. We have done an exploratory, double-blind, randomized, placebo-controlled pilot trial to investigate the tissue-specific effects of 2.5 mg tibolone on breast cancer in postmenopausal women, in particular on tissue proliferation (STEM, Study of Tibolone Effects on Mamma carcinoma tissue). Experimental Design: Postmenopausal women with initially stage I/II, estrogen receptor-positive (ER+) primary breast cancer, were randomly assigned to 14 days of placebo or 2.5 mg/d tibolone. Core biopsies of the primary tumor were obtained before and after treatment. Ki-67 and apoptosis index were analyzed in baseline and corresponding posttreatment specimen. Results: Of 102 enrolled patients, 95 had evaluable data. Baseline characteristics were comparable between both treatment groups. Breast cancer cases are mainly invasive (99%), stage I or II (42% and 50% respectively), and ER+ (99%). Median intratumoral Ki-67 expression at baseline was 13.0%, in the tibolone group and 17.8% in the placebo group, and decreased to 12.0% after 14 days of tibolone while increasing to 19.0% in the placebo group. This change from baseline was not significantly different between tibolone and placebo (Wilcoxon test; P = 0.17). A significant difference was observed between the treatment groups when the median change from baseline apoptosis index was compared between the treatment groups (tibolone, 0.0%; placebo, +0.3%; Wilcoxon test; P = 0.031). The incidence of adverse effects was comparable. Conclusions: In ER+ breast tumors, 2.5 mg/d tibolone given for 14 days has no significant effect on tumor cell proliferation

Manipulation of the Spatial Grazing Behaviour of Livestock in Extensive Grassland Systems

Spatial behaviour of livestock is a critical factor in grassland management. Recent and ongoing research suggests that new approaches can be used to manipulate where cattle graze. The combination of strategic supplement placement and low-stress herding can be used to target cattle grazing and potentially may be useful for managing fine fuels. A phenotype to genotype association study of cattle spatial behavior suggests that use of rugged terrain and areas far from water is inherited. Although more research is needed, selection for animals specifically adapted for mountainous terrain or extensive paddocks may be an alternative for managing grasslands in the near future