The Moving Middle: Migration, Place Premiums and Human Development in Bolivia

Over half of Bolivian heads of household are lifetime migrants. This paper looks at the long term impact of internal migration over human development in Bolivia. Three issues frame these effects. First, twenty five years of rural to urban migration have transformed the demographic profile of Bolivian society. The new middle third is younger, more bilingual and better educated, with more access to social services than in the past. The poorest of the poor, however, did not migrate to the extent of the non-poor. Second, urban workers make approximately four times as much wages as identical workers in rural areas, controlling for age, ethnicity, and years of schooling. Two caveats dampen this place premium effect: schooling quality and informal insurance mechanisms that make migration more costly. Third, increases in human development can be associated to an “urbanization dividend” that made social services more accessible to first and second generation migrants over a twenty-five year period. Future increases in human development, however, are likely to depend on providing quality services and expanding socials services to the rural poor, rather on gains from urbanization. The key policy challenges of the future include both an expansion of services to the poorest of the poor in rural areas and breaking down discrimination barriers against women and indigenous people in urban labor markets.Migration, human development, poverty, employment, schooling

The Moving Middle: Migration, Place Premiums and Human Development in Bolivia

Over half of Bolivian heads of household are lifetime migrants. This paper looks at the long term impact of internal migration over human development in Bolivia. Three issues frame these effects. First, twenty five years of rural to urban migration have transformed the demographic profile of Bolivian society. The new middle third is younger, more bilingual and better educated, with more access to social services than in the past. The poorest of the poor, however, did not migrate to the extent of the non-poor. Second, urban workers make approximately four times as much wages as identical workers in rural areas, controlling for age, ethnicity, and years of schooling. Two caveats dampen this place premium effect: schooling quality and informal insurance mechanisms that make migration more costly. Third, increases in human development can be associated to an “urbanization dividend” that made social services more accessible to first and second generation migrants over a twenty-five year period. Future increases in human development, however, are likely to depend on providing quality services and expanding socials services to the rural poor, rather on gains from urbanization. The key policy challenges of the future include both an expansion of services to the poorest of the poor in rural areas and breaking down discrimination barriers against women and indigenous people in urban labor markets.Migration, human development, poverty, employment, schooling

Determinación de costos de producción en granjas productoras de lechón

El objetivo de este trabajo fue determinar los costos de producción de 1249 camadas de lechones destetadas (cubrición-destete) en granjas productoras de lechón de pequeña escala, en diferentes regiones del altiplano en México, durante un año (julio 2010 a junio 2011). Se definieron tres estratos de acuerdo al número de cerdas reproductoras: Estrato I de 5-10 (n=8); Estrato II de 1 1-49 (n=10); Estrato III de 50-100 (n=4). La ganancia neta fue positiva para todos los estratos: Estrato I de $206 pesos por lechón vendido, sin considerar el pago por concepto de mano de obra y$12 con pago de mano de obra; Estrato II de $152; y Estrato III de$165 (14.49, 0.84, 10.69 y 1 1.60 dólares estadounidenses, con una tasa peso-dólar de 1:0.0703). La relación B/C fue, para el Estrato I = 1.53 % (sin pago de mano de obra) y 1.04 % (con pago de mano de obra); Estrato II de 1.35 %; y Estrato III 1.39 %

The Moving Middle: Migration, Place Premiums and Human Development in Bolivia

Over half of Bolivian heads of household are lifetime migrants. This paper looks at the long term impact of internal migration over human development in Bolivia. Three issues frame these effects. First, twenty five years of rural to urban migration have transformed the demographic profile of Bolivian society. The new middle third is younger, more bilingual and better educated, with more access to social services than in the past. The poorest of the poor, however, did not migrate to the extent of the non-poor. Second, urban workers make approximately four times as much wages as identical workers in rural areas, controlling for age, ethnicity, and years of schooling. Two caveats dampen this place premium effect: schooling quality and informal insurance mechanisms that make migration more costly. Third, increases in human development can be associated to an “urbanization dividend” that made social services more accessible to first and second generation migrants over a twenty-five year period. Future increases in human development, however, are likely to depend on providing quality services and expanding socials services to the rural poor, rather on gains from urbanization. The key policy challenges of the future include both an expansion of services to the poorest of the poor in rural areas and breaking down discrimination barriers against women and indigenous people in urban labor markets

Diseño de un sistema de gestión de mantenimiento preventivo mecánico con la metodología RCM2, para la aplicación en una chancadora cónica MP1000; de una empresa minera cuprífera del sur del Perú

El objetivo de la presente investigación, fue diseñar un sistema de gestión de mantenimiento preventivo mecánico, para la aplicación en una chancadora cónica MP1000. Por ello, la Investigación utilizó un diseño no experimental, de tipo básico, de nivel descriptivo con propuesta y de corte transversal. Las unidades de observación fueron diez chancadoras cónicas MP1000/HP700 de una empresa minera cuprífera del sur del Perú, operativas hasta junio del año 2020. El muestreo fue de tipo no probabilístico e intencionado. Se utilizó la técnica de observación documental de datos provenientes de las operaciones de mantenimiento PETS, manuales e historiales de falla de la chancadora y como instrumentos: fichas de recolección de datos de las fuentes mencionadas. Los resultados de la auditoría manifestaron que el área de mayor puntaje fue planificación y programación; mientras que las de menor puntaje y que requieren mayor atención son: el área de mantenimiento preventivo y tecnología del equipo, y el área de soporte del equipo. El análisis de criticidad de los sistemas de chancado mostró que el 30% de los sistemas evaluados tienen una criticidad de tipo “A” (Críticos), el 21% poseen una criticidad de tipo “B” (Semicríticos) y el 49% tienen una criticidad de tipo “C” (No críticos). Las chancadoras cónicas MP1000 son equipos críticos; y requieren un mantenimiento enfocado en la metodología del RCM2 y AMEF. El análisis de criticidad de los sistemas de la Chancadora MP1000 mostró que: dos sistemas son de criticidad A (Críticos), tres sistemas son de criticidad B (Semicríticos), y tres sistemas son de criticidad C (No críticos). Se tiene mayor criticidad en los sistemas de la unidad de chancado y sistema de poder. Los subsistemas de la unidad de chancado con mayor criticidad son: los forros y el main shaft. Se diseñó un sistema de gestión de mantenimiento con la metodología RCM2 para la aplicación en la Chancadora Cónica MP1000 apoyados en la elaboración de planes con disciplinas de mantenimiento preventivo, lubricación, inspección y predictivo. Cada plan está subdividido por sistemas y cada sistema contiene tareas con especialidades diferentes. Finalmente, la investigación concluyó que, se diseñó un sistema de gestión de mantenimiento inicial con aplicación de: una auditoría, que identificó los puntos a mejorar en el área de mantenimiento de chancado; el análisis de criticidad, que clasificó a los equipos; y el desarrollo de la propuesta de nuevas estrategias y tareas de mantenimiento mediante la aplicación de la metodología RCM2 y desarrollo del AMEF y el análisis de confiabilidad y disponibilidad por la distribución de Weibull

Ileal apparent and standardized amino acid digestibility of soybean and colza meal in diets for finishing pigs

Agri-food chains generate by-products such as soybean and colza meal for animal feed. Their nutritional value is variable and should be analysed for better quality control before their inclusion in balanced diets. The objective was to determine the content and ileal apparent and standardized digestibility of protein and amino acids (AA) of soybean (PS) and colza meal (PC) as a source of protein in diets for finishing pigs. The experimental units were arranged in a 3×3 Latin square design repeated. The treatments (T) were T1: PS+corn starch, T2: PC+corn starch, and T3: corn starch (Control), which were randomly assigned to six pigs cannulated in distal ileum (PV 75±1.2 kg). The variables were contents and apparent ileal and standardized ileal digestibility of amino acids in soybean and colza meal. To determine digestibility, chromic oxide was added to the diets. The protein and fat contents were higher in the soybean meal. Ash, crude fibre, neutral detergent fibre, acid detergent fibre, phosphorus and calcium contents were higher in the colza meal. Essential amino acid content was higher in soybean meal, but methionine was higher in colza meal. Apparent ileal digestibility (DIA) of total amino acids was similar (p > 0.05) among protein ingredients; but for lysine and threonine it was higher (p ≤ 0.05) in soybean meal, except methionine. Methionine DIA was 89.78 %, 3.88 % higher (p ≤ 0.05) in colza meal. Standardized ileal digestibility (DIE) of total amino acids was similar (p > 0.05) among ingredients, but lysine and threonine were higher (p ≤ 0.05) in soybean meal. DIE was different (p ≤ 0.05) among ingredients for all amino acids except methionine. Ileal and standardized digestibility of all amino acids were higher in soybean meal, except methionine, which was higher in colza meal. The DIA of total amino acids was similar in both protein ingredients, except lysine and threonine in soybean meal and methionine in colza meal