"Access to Markets and Farm Efficiency: A Study of Rice Farms in the Bicol Region, Philippines"

This paper presents an empirical investigation of the relationship between the spread, spatially and temporally, of market institutions and improvements in the productivity and efficiency of farmers. The data used in this study were collected over two decades in a sample of rice farms in the Bicol Region of the Philippines. Our estimates reveal a significant inverse relationship between distance from the market and farm productivity and efficiency in 1983. While there are substantial improvements in yields, unit costs, and efficiency in the two decades that followed, the gains are larger in the more remote and sparsely populated villages. This finding suggests that the relationship between remoteness and farm outcomes has weakened over time. We also find that the development of markets in the peripheral villages and the improved connectivity between the peripheral villages and market centers are facilitated by population growth, infrastructural investments (specifically, irrigation and roads), and the availability of agricultural extension programs.Farm Efficiency; Agricultural Markets; Institutional Conditions; Philippines

Assessment of research needs for sustainability of unconventional machining processes

AbstractThe use of unconventional machining (UCM) practices is increasing for product manufacture particularly when machining difficult to cut materials and when high precision is required. There is plenty of research conducted on improving sustainability of traditional machining. However, sustainability studies on unconventional/non-traditional machining practices are few. This review aims to determine the current state of the art in sustainability assessment of unconventional machining practices and identify gaps in research. An extensive review was carried out and analysed using a qualitative data analysing software. The analysis shows that only 25 publications directly and indirectly discuss the matter of sustainability of UCM. Out of this almost 70% of publications were recorded after year 2006 showing a clear evidence of uncovered research gap in the field with a growing interest. Despite this trend, evidence on studies which are explicitly dedicated to analyse the sustainability of UCM are rare

"Housing Inequality in the United States: A Decomposition Analysis of Racial and Ethnic Disparities in Homeownership"

In recent years, as the homeownership rate in the United States reached its highest level in history, homeownership itself remained unevenly distributed, particularly along racial and ethnic lines. By using data from the 2000 Integrated Public Use Microdata Series (IPUMS) and 2006 American Community Survey (ACS) to study the trajectory into homeownership of black, Asian, white, and Latino households, this paper explores the various socioeconomic and demographic characteristics, as well as the distinct immigration experiences and spatial patterns that shape racial and ethnic inequality in homeownership. The unique (merged) dataset enables the authors to distinguish assimilation (length of residence) from immigration cohort effects, and to control for various spatial characteristics at the PUMA (Public Use Microdata Area) level. The paper employs a decomposition technique that delineates the distinct effects that composition differentials have on the visible white-minority disparity in homeownership. The findings reveal substantial differences along racial-ethnic lines, highlight the importance of immigration and spatial context in determining Asian and Mexican homeownership rates, and emphasize the unique role that family structure and unobserved factors (e.g. prejudice and discrimination) continue to play in shaping the black-white homeownership gap.

Explosive volcanism, shock metamorphism and the K-T boundary

The issue of whether shocked quartz can be produced by explosive volcanic events is important in understanding the origin of the K-T boundary constituents. Proponents of a volcanic origin for the shocked quartz at the K-T boundary cite the suggestion of Rice, that peak overpressures of 1000 kbars can be generated during explosive volcanic eruptions, and may have occurred during the May, 1980 eruption of Mt. St. Helens. Attention was previously drawn to the fact that peak overpressures during explosive eruptions are limited by the strength of the rock confining the magma chamber to less than 8 kbars even under ideal conditions. The proposed volcanic mechanisms for generating pressures sufficient to shock quartz are further examined. Theoretical arguments, field evidence and petrographic data are presented showing that explosive volcanic eruptions cannot generate shock metamorphic features of the kind seen in minerals at the K-T boundary

"Racial Preferences in a Small Urban Housing Market: A Spatial Econometric Analysis of Microneighborhoods in Kingston, New York"

This paper use spatial econometric models to test for racial preferences in a small urban housing market. Identifying racial preferences is difficult when unobserved neighborhood amenities vary systematically with racial composition. We adopt three strategies to redress this problem: (1) we focus on housing price differences across microneighborhoods in the small and relatively homogenous city of Kingston, New York; (2) we introduce GIS-based spatial amenity variables as controls in the hedonic regressions; and (3) we use spatial error and lag models to explicitly account for the spatial dependence of unobserved neighborhood amenities. Our simple OLS estimates agree with the consensus in the literature that black neighborhoods have lower housing prices. However, racial price discounts are no longer significant when we account for the spatial dependence of errors. Our results suggest that price discounts in black neighborhoods are caused not by racial preferences but by the demand for amenities that are typically not found in black neighborhoods.Housing; Race; Neighborhood Amenities; Spatial Econometrics Commonwealth of Independent States

Vortex Effects for Canard-wing Configurations at High Angles of Attack in Subsonic Flow

A fully three-dimensional subsonic panel method that can handle arbitrary shed vortex wakes is used to compute the nonlinear forces and moments on simple canard-wing configurations. The lifting surfaces and wakes are represented by doublet panels. The Mangler-Smith theory is used to provide an initial estimate for the vortex sheet shed from the leading edge. The trailing-edge wake and the leading-edge wake downstream of the trailing edge are assumed to be straight and leave the trailing edge at an angle of alpha/2. Results indicate good agreement with experimental data up to 40 degs angle of attack