Cardinality-based equality of opportunities

We study possible rankings of opportunity profiles. An opportunity profile is a list of opportunity sets, one for each agent in the society. We compare profiles on the basis of the notion of “equality of opportunities”. Our main results show the necessary and sufficient conditions for this comparison to be made using exclusively the information provided by two cardinal measures: the number of common alternatives in all sets of a given profile and the difference between the number of alternatives in the individual sets. We also show that, under additional axioms, we can combine these criteria only in a weighted procedure or in some lexicographic refinements of a weighted procedure.      

Employment shifts, economic reform and the changes in public/private sector wages in Mexico: 1987–1997

Over the last decade, the public sector in Mexico experienced substantial fiscal reform, divestiture of public enterprises, and the elimination of many regulations affecting pay and employment. This study analyzes the changes in the public/private sector differences in wages during the 1987–1997 period. The results from analyzing microdata from the Encuesta Nacional de Empleo Urbano show that relative public sector wages increased from 1987 to 1997. Most of the relative wage increase in the public sector can be explained by increases in the price of skills and by changes in sorting across sectors. The results have important public policy implications since they suggest that public sector workers earn more and their wages have grown faster than those of their private sector counterparts. As such, policies contemplating public sector reform should take into account the effect of these measures on the inter-sectoral income distribution and the overall economic growth. First version received: April 2000/Final version received: December 2000     

Design and construction of an experimental pervious paved parking area to harvest reusable rainwater

Pervious pavements are sustainable urban drainage systems already known as rainwater infiltration techniques which reduce runoff formation and diffuse pollution in cities. The present research is focused on the design and construction of an experimental parking area, composed of 45 pervious pavement parking bays. Every pervious pavement was experimentally designed to store rainwater and measure the levels of the stored water and its quality over time. Six different pervious surfaces are combined with four different geotextiles in order to test which materials respond better to the good quality of rainwater storage over time and under the specific weather conditions of the north of Spain. The aim of this research was to obtain a good performance of pervious pavements that offered simultaneously a positive urban service and helped to harvest rainwater with a good quality to be used for non potable demands.     

Using Similarity Analyses to Scale Out Research Findings Across Andean Watershed Basins

Abstract

Strategic research in agriculture and natural resources carried out by international research centers is deemed a public good and should, sooner or later, be put into the hands of development, governmental and non-governmental organizations. However, this research is usually done at specific pilot sites; there is a greater need to know how representative those sites are in relation to the diversity of contexts in other locations. Such is the case with the Challenge Program on Water and Food (CPWF), a global initiative in water research promoted by the Consultative Group on International Agricultural Research (CGIAR), which is developing and implementing strategic research in nine basins located in the tropics of Africa, Asia and South America. Given that resources are not available to collect data from the whole of the region, pilot sites are needed. It is hoped that research outputs obtained in the selected pilot sites can be the basis for scaling out solutions to similar situations in neighbouring or adjacent areas in same or different basins.

In order to contribute to the scaling-out process, different classification methodologies were applied to determine how specific watershed basins are representative of larger areas. The Andean eco-region served as a case study but the methods can easily be applied in other regions. The spatial diversity of biophysical and social conditions across the Andes requires careful site selection. Two methods, a combination of Weight of Evidence (WofE) and Logistic Regression (LR) methods and Fast Cluster analysis, were used to determine the similarity of selected sites with those excluded. A 1-km study resolution covering most of the Andes eco-region included annual rainfall, elevation, length of growing period, land cover, roads and population density as the key variables. Results showed complementarities between the two methods in presenting a probability surface of similarity across the Andes and a clustering of similar sites inside and outside the pilot basins. The output information forms a strong basis for devising plans to scale out research findings from the pilot basins to the whole region.     

A novel combined electrochemical-magnetic method for water treatment

Electrocoagulation (EC) is a wastewater treatment process in which aqueous pollutants can be removed by adsorption, entrapment, precipitation or coalescence during a coagulation step produced by electrochemically generated metallic species. When using Fe as the sacrificial electrode, Fe(2+) and Fe(3+) ions are formed. As Fe(3+) species are paramagnetic, this property can in principle be used to facilitate their removal through the application of a magnetic field. In the present work we present a proof-of-concept for a combined electrochemical-magnetic method for pollutant removal. For this approach, the amounts of Fe(2+) and Fe(3+) produced in an EC cell at various voltages were measured by spectroscopic methods to confirm that Fe(3+) species predominate (up to 84%). The effectiveness of the presence of a magnetic field in the precipitation of coagulants from a suspension was confirmed by monitoring the turbidity change versus time with and without exposure to a magnetic field, up to a 30% improvement.     

Replacing dichromate with hydrogen peroxide in the chemical oxygen demand (COD) test

The widely used standard method for chemical oxygen demand (COD) involves hazardous chromium species, and its two-hour heating protocol entails a substantial amount of energy expenditure. In the present work we report a proof of concept for a major modification of this method in the range 10-800 mgCOD/L, whereby H2O2 is proposed as a replacement oxidizer. This modification not only reduces the use of unsafe chromium species but also allows for the use of milder conditions that decrease the total energy outlay. The results are comparable with those obtained either with the standard method or with a commercial Hach? kit.     

The Weekend and 'Reverse' Weekend Effects: An Analysis by Month of the Year, Week of the Month, and Industry

In this paper, we examine whether the 'reverse' weekend effect recently documented by Brusa, Liu and Schulman (2000) is concentrated in a few industries or widely spread across all the industries. The findings in this paper indicate that the 'reverse' weekend effect exists not only in broad indices, but also in most industries . The results suggest that the 'reverse' weekend effect may be driven by economic events that affect all industries, rather than industry‐specific factors . Although the patterns of Monday returns are similar between broad indices and industry indices, they are different between the pre ‐ and the post ‐1988 periods. Monday returns tend to be negative in the pre ‐1988 period, but tend to be positive in the post ‐1988 period, for both broad market indices and industry indices. These conclusions are valid even after considering the influence of the month‐of‐the‐year and the week‐of‐the‐month effects.     

Using partial identification methods to estimate the effect of violence against women on their children’s health outcomes

A growing literature in economics seeks to estimate the costs of violence against women by examining, for example, its impact on the health outcomes of their children. However, it is difficult to assign a causal interpretation to these nonexperimental studies due to the presence of unobservable characteristics affecting violence and health outcomes simultaneously. The lack of credible instrumental variables applicable in several countries further limits our knowledge. I address this gap by using new partial identification methods to estimate the relative size of the unobservables needed to eliminate the estimated effects in nonexperimental studies. I also expand the external validity of the analysis by using data from five standardized nationally representative household surveys in Latin America. Consistent with previous studies, cross-sectional estimates show large negative associations between violence against women and an array of child health outcomes. However, when accounting for omitted variable bias, at best, two-thirds of the estimates remain robust and they are concentrated on the outcomes with the largest cross-sectional estimated impacts.     

Monday returns and asset pricing

The seasonal patterns observed on Monday stock returns are still unexplained by different asset pricing models. We attempt to fill this gap in the finance literature by using the Fama-French (Journal of Financial Economics 33:3–56, 1993) risk factors to explain the Monday seasonal. The results in the study show that Monday returns are explained by risk factors such as the market return, the size of the firms, and the book-to-market ratios of firms.     

Model for evaluating the environmental sustainability of energy projects

This article focuses on the problem of assessing the environmental sustainability of energy projects. For this purpose an original model, which is based on various indicators that measure the environmental sustainability of energy projects, has been developed. This model, so called index of environmental sustainability of energy projects (IESEP), can be used in scenario comparison, while measuring the effectiveness of the proposed alternatives. Finally, an example of how to use this model is provided by analyzing alternatives to ameliorate the environmental sustainability of a hydroelectric project. In doing so, it is possible to show the usefulness of this model when used as a decision making tool for energy planners.