Economies of scale in the water sector: A survey of the empirical literature

The issue of the most favorable size and optimal industry structure in the water sector is a relevant topic in many countries, due to fragmentation of the water sector and the key role played by municipalities. Important debates are taking place worldwide about how to provide universal access to the water supply and offer an efficient service. Regarding efficiency, the possibility of exploiting economies of scale would imply better resource allocation, the potential for lower water charges, and greater geographical coverage. By surveying the empirical research from different parts of the world, we aim to shed some light on the topic of economies of scale, and to provide a synthesis of the literature. We also aim to determine whether there is a tradeoff between centralization and decentralization. Our survey shows that, for several countries, variations in efficiency of water provision due to economies of scale do exist. Increases in efficiency related to economies of scale are found for populations in the range of 100,000 to 1 million people served. For larger populations, volume-or density-constant returns to scale are observed, followed by decreasing returns to scale; the reverse occurs for smaller values, suggesting that cost savings are derived from consolidation of providers. Returns to scale refer to changes in output resulting where all inputs increase by a constant factor. If output increases by that same proportional change, then there are constant returns to scale. If output increases by less than that proportional change, there are decreasing returns to scale. If output increases by more than that proportional change, there are increasing returns to scale. Returns to scale is a technological phenomenon, due to the relationship between inputs and outputs in the production function. Economies of scale refer to reductions in unit cost as the scale of production increases. Diseconomies of scale are the opposite: increasing in unit costs as the scale of production increases. Scale changes mean a proportional increase in all factors of production. Economies of scale are a economical phenomenon, due to the relationship between unit costs and the level of production.Fil: Ferro, Gustavo Adolfo. Universidad Argentina de la Empresa; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lentini, Emilio J.. Universidad de Buenos Aires; ArgentinaFil: Mercadier, Augusto C.. Universidad Nacional de La Plata; Argentin

Economías de escala en agua y saneamiento: examen de la literatura

Este estudio se ocupa de relevar la literatura internacional sobre economías de escala en el sector de agua y saneamiento, reseñarla y extraer hilos conductores. En todo el mundo está en discusión cómo lograr un acceso más equitativo y una prestación más eficiente. Un tema vinculado con la eficiencia es la posibilidad de aprovechar economías de escala al dimensionar la prestación de agua potable y alcantarillado. La discusión teórica y los resultados empíricos sobre economías de escala en agua y saneamiento sirven para detectar si hay o no un quid-pro-quo entre concentrar y desconcentrar servicios como medida de política. Los estudios relevados en un conjunto grande de países, arrojan economías de escala (en diversos países con diferentes situaciones) en poblaciones cubiertas por entre 100 mil, hasta cerca de 1 millón de habitantes (en algunos casos se extiende a varios millones), o con densidades poblacionales de hasta 250 habitantes por kilómetro de red, o con volúmenes entregados a la red de 70 millones de m3 al año. Con poblaciones, volúmenes o densidades mayores, empiezan primero los rendimientos constantes a escala y posteriormente las deseconomías de escala; con valores menores, hay ahorros de costos por aglomerar.water; sanitation; scale economies

Magmatic and hydrothermal behavior of uranium in syntectonic leucogranites: The uranium mineralization associated with the Hercynian Guérande granite (Armorican Massif, France)

Most of the hydrothermal uranium (U) deposits from the European Hercynian belt (EHB) are spatially associated with Carboniferous peraluminous leucogranites. In the southern part of the Armorican Massif (French part of the EHB), the Guérande peraluminous leucogranite was emplaced in an extensional deformation zone at ca. 310 Ma and is spatially associated with several U deposits and occurrences. The apical zone of the intrusion is structurally located below the Pen Ar Ran U deposit, a perigranitic vein-type deposit where mineralization occurs at the contact between black shales and Ordovician acid metavolcanics. In the Métairie-Neuve intragranitic deposit, uranium oxide-quartz veins crosscut the granite and a metasedimentary enclave. Airborne radiometric data and published trace element analyses on the Guérande leucogranite suggest significant uranium leaching at the apical zone of the intrusion. The primary U enrichment in the apical zone of the granite likely occurred during both fractional crystallization and the interaction with magmatic fluids. The low Th/U values (18Owhole rock = 9.7–11.6‰ for deformed samples and δ18Owhole rock = 12.2–13.6‰ for other samples) indicate that the deformed facies of the apical zone underwent sub-solidus alteration at depth with oxidizing meteoric fluids. Fluid inclusion analyses on a quartz comb from a uranium oxide-quartz vein of the Pen Ar Ran deposit show evidence of low-salinity fluids (1–6 wt.% NaCl eq.), in good agreement with the contribution of meteoric fluids. Fluid trapping temperatures in the range of 250–350 °C suggest an elevated geothermal gradient, probably related to regional extension and the occurrence of magmatic activity in the environment close to the deposit at the time of its formation. U-Pb dating on uranium oxides from the Pen Ar Ran and Métairie-Neuve deposits reveals three different mineralizing events. The first event at 296.6 ± 2.6 Ma (Pen Ar Ran) is sub-synchronous with hydrothermal circulations and the emplacement of late leucogranitic dykes in the Guérande leucogranite. The two last mineralizing events occur at 286.6 ± 1.0 Ma (Métairie-Neuve) and 274.6 ± 0.9 Ma (Pen Ar Ran), respectively. Backscattered uranium oxide imaging combined with major elements and REE geochemistry suggest similar conditions of mineralization during the two Pen Ar Ran mineralizing events at ca. 300 Ma and ca. 275 Ma, arguing for different hydrothermal circulation phases in the granite and deposits. Apatite fission track dating reveals that the Guérande granite was still at depth and above 120 °C when these mineralizing events occurred, in agreement with the results obtained on fluid inclusions at Pen Ar Ran. Based on this comprehensive data set, we propose that the Guérande leucogranite is the main source for uranium in the Pen Ar Ran and Métairie-Neuve deposits. Sub-solidus alteration via surface-derived low-salinity oxidizing fluids likely promoted uranium leaching from magmatic uranium oxides within the leucogranite. The leached out uranium may then have been precipitated in the reducing environment represented by the surrounding black shales or graphitic quartzites. As similar mineralizing events occurred subsequently until ca. 275 Ma, meteoric oxidizing fluids likely percolated during the time when the Guérande leucogranite was still at depth. The age of the U mineralizing events in the Guérande region (300–275 Ma) is consistent with that obtained on other U deposits in the EHB and could suggest a similar mineralization condition, with long-term upper to middle crustal infiltration of meteoric fluids likely to have mobilized U from fertile peraluminous leucogranites during the Late Carboniferous to Permian crustal extension events

Returns to scale in water and sanitation: estimates for Latin America

Most countries around the world are strongly debating ways to yield more equitable access and a more efficient provision. One issue linked to efficiency is the achievement of scale economies in the industry and the optimal dimension of water and sanitation providers. Changes in the industrial structure of the sector, through mergers in highly atomized services, the breakup of very concentrated services, or the property discussion (private versus public) are major issues. These decisions have often become politicized because of the social complexity of the sector. Empirical findings of the different models reveal the existence of increasing returns to scale in Latin American water provision based on an ADERASA database (a 2005 cross section of 90 providers in 14 countries). The study of returns to scale incorporates a technical argument into the discussion because–as our study suggests–the prescription could be to agglomerate small providers.Fil: Ferro, Gustavo Adolfo. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lentini, Emilio J.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Estudios Transdisciplinarios del Agua; ArgentinaFil: Mercadier, Augusto C.. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; ArgentinaFil: Romero, Carlos A.. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; Argentin

Returns to scale in water and sanitation: estimates for Latin America

Most countries around the world are strongly debating ways to yield more equitable access and a more efficient provision. One issue linked to efficiency is the achievement of scale economies in the industry and the optimal dimension of water and sanitation providers. Changes in the industrial structure of the sector, through mergers in highly atomized services, the breakup of very concentrated services, or the property discussion (private versus public) are major issues. These decisions have often become politicized because of the social complexity of the sector. Empirical findings of the different models reveal the existence of increasing returns to scale in Latin American water provision based on an ADERASA database (a 2005 cross section of 90 providers in 14 countries). The study of returns to scale incorporates a technical argument into the discussion because–as our study suggests–the prescription could be to agglomerate small providers.Fil: Ferro, Gustavo Adolfo. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lentini, Emilio J.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Estudios Transdisciplinarios del Agua; ArgentinaFil: Mercadier, Augusto C.. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; ArgentinaFil: Romero, Carlos A.. Universidad Argentina de la Empresa. Facultad de Ciencias Económicas. Instituto de Economía; Argentin

Los servicios urbanos de agua potable y saneamiento en Argentina: Estado actual y desafíos.

Capítulo de libroEste artículo tiene por objeto describir el estado actual de los servicios urbanos de agua y cloaca por red en la Argentina y plantear cuáles son los desafíos futuros. Para lo cual también se analiza la situación actual y desafíos de los países de la región para el cumplimiento del Objetivo de Desarrollo Sostenible 6, “Garantizar la disponibilidad y la gestión sostenible del agua y el saneamiento para todos”. En América Latina y el Caribe, la población urbana representa el 81,1%, y para el 2030 esa proporción alcanzaría el 84,1%. Este crecimiento demográfico, combinado con la concentración poblacional en áreas urbanas, requiere que la infraestructura urbana crezca a una tasa superior para atender esta demanda creciente e incorporar a quienes a la fecha no cuentan con los servicios de agua y cloacas. Al analizar la situación actual del sector en la Argentina sobresalen los déficits de cobertura: 13% de la población no tiene acceso a agua por red pública y el 42% a cloacas. Por otro lado, respecto a la organización sectorial, se destacan la pluralidad de prestadores, la falta de información sistematizada y la disparidad respecto de los niveles de desempeño alcanzados por los distintos operadores. En este contexto, se analiza el Plan Nacional de Agua Potable y Saneamiento formulado por el Gobierno nacional en 2016, que marca los lineamientos futuros y establece como objetivo principal alcanzar la cobertura de agua al 100% y lograr un 75% de cobertura de cloaca en las áreas urbanas del país.Fil: Lentini, Emilio J. Centro de Estudios Transdisciplinarios del Agua (Instituto UBA)/Gestión Ambiental Metropolitana (FADU/UBA), Argentina. Email: [email protected]: Brenner, Federica. Centro de Estudios Transdisciplinarios del Agua (CETA-UBA), Argentina. Email: [email protected]: Mercadier, Augusto. Universidad Nacional de La Plata/Ente Regulador de Agua y Saneamiento (ERAS), Argentina. Email: [email protected]

Eficiencia energética en el sector de agua y saneamiento: estimaciones utilizando una función de requerimientos de insumo

We analyze by means of frontier methods (input requirement function) the relative energy efficiency of urban water and sanitation providers in Brazil. We estimate energy savings through measures the sector could implement on variables which control. We find a 63 percent efficiency average, with respect to best practices in the sample (the frontier). We estimate that a 10 percent reduction in unaccounted-for water can reduce 4.2 percent the electricity consumption for the whole sample; also, a reduction in 10 percent of the breach of coverage between sanitation and water can achieve reductions of 1.45 percent in the input under study

EXPERIMENTAL STUDIES OF SOLUBILITY OF ELEMENTAL SULPHUR IN SUPERCRITICAL CARBON DIOXIDE BETWEEN 10 AND 40 MPA

International audienc

Eficiencia energética en el sector de agua y saneamiento: estimaciones utilizando una función de requerimientos de insumo

We analyze by means of frontier methods (input requirement function) the relative energy efficiency of urban water and sanitation providers in Brazil. We estimate energy savings through measures the sector could implement on variables which control. We find a 63 percent efficiency average, with respect to best practices in the sample (the frontier). We estimate that a 10 percent reduction in unaccounted-for water can reduce 4.2 percent the electricity consumption for the whole sample; also, a reduction in 10 percent of the breach of coverage between sanitation and water can achieve reductions of 1.45 percent in the input under study