Tariff reductions and labor demand elasticities : evidence from Chinese firm-level data

International production fragmentation has been a global trend for decades, becoming especially important in Asia where the manufacturing process is fragmented into stages and dispersed around the region. This paper examines the effects of input and output tariff reductions on labor demand elasticities at the firm level. For this purpose, we consider a simple heterogenous firm model in which firms are allowed to export their products and to use imported intermediate inputs. The model predicts that only productive firms can use imported intermediate inputs (outsourcing) and tend to have larger constant-output labor demand elasticities. Input tariff reductions would lower the factor shares of labor for these productive firms and raise conditional labor demand elasticities further. We test these empirical predictions, constructing Chinese firm-level panel data over the 2000--2006 period. Controlling for potential tariff endogeneity by instruments, our empirical studies generally support these predictions.

Quasi-experimental evidence on the drivers of index-based livestock insurance demand in Southern Ethiopia

Microinsurance is widely considered an important tool for sustainable poverty reduction, especially in the face of increasing climate risk. Although index-based microinsurance, which should be free from the classical incentive problems, has attracted considerable attention, uptake rates have generally been weak in low-income rural communities. We explore the purchase patterns of index-based livestock insurance in southern Ethiopia, focusing in particular on the role of accurate product comprehension and price, including the prospective impact of temporary discount coupons on subsequent period demand due to price anchoring effects. We find that randomly distributed learning kits contribute to improving subjects' knowledge of the products; however, we do not find strong evidence that the improved knowledge per se induces greater uptake. We also find that reduced price due to randomly distributed discount coupons has an immediate, positive impact on uptake, without dampening subsequent period demand due to reference-dependence associated with price anchoring effects.

Production sharing, demand spillovers and CO2 emissions : the case of Chinese regions in GVCs

This study adopts the perspective of demand spillovers to provide new insights regarding Chinese domestic-regions' production position in global value chains and their associated CO2 emissions. To this end, we constructed a new type of World Input-Output Database in which China's domestic interregional input-output table for 2007 is endogenously embedded. Then, the pattern of China's regional demand spillovers across both domestic regions and countries are revealed by employing this new database. These results were further connected to endowments theory, which help to make sense of the empirical results. It is found that China's regions locate relatively upstream in GVCs, and had CO2 emissions in net exports, which were entirely predicted by the environmental extended HOV model. Our study points to micro policy instruments to combat climate change, for example, the tax reform for energy inputs that helps to change the production pattern thus has impact on trade pattern and so forth.

Forecasting inbound tourists in Cambodia

Forecasting tourism demand is crucial for management decisions in the tourism sector. Estimating a vector autoregressive (VAR) model for monthly visitor arrivals disaggregated by three entry points in Cambodia for the years 2006–2015, I forecast the number of arrivals for years 2016 and 2017. The results show that the VAR model fits well with the data on visitor arrivals for each entry point. Ex post forecasting shows that the forecasts closely match the observed data for visitor arrivals, thereby supporting the forecasting accuracy of the VAR model. Visitor arrivals to Siem Reap and Phnom Penh airports are forecast to increase steadily in future periods, with varying fluctuations across months and origin countries of foreign tourists.

Cooperation in the knowledge transfer process: evidence from the demand side in Mexico

This paper presents the results of the analysis focused on scientific-technological KT in four Mexican firms and carried out by the case study approach. The analysis highlights the use of KT mechanisms as a means to obtain scientific-technological knowledge, learning, building S&T capabilities, and achieve the results of the R&D and innovation by firms.

Ubiquitous green computing techniques for high demand applications in smart environments

Ubiquitous sensor network deployments, such as the ones found in Smart cities and Ambient intelligence applications, require constantly increasing high computational demands in order to process data and offer services to users. The nature of these applications imply the usage of data centers. Research has paid much attention to the energy consumption of the sensor nodes in WSNs infrastructures. However, supercomputing facilities are the ones presenting a higher economic and environmental impact due to their very high power consumption. The latter problem, however, has been disregarded in the field of smart environment services. This paper proposes an energy-minimization workload assignment technique, based on heterogeneity and application-awareness, that redistributes low-demand computational tasks from high-performance facilities to idle nodes with low and medium resources in the WSN infrastructure. These non-optimal allocation policies reduce the energy consumed by the whole infrastructure and the total execution time.

Neural network controller for active demand side management with PV energy in the residential sector

In this paper, we describe the development of a control system for Demand-Side Management in the residential sector with Distributed Generation. The electrical system under study incorporates local PV energy generation, an electricity storage system, connection to the grid and a home automation system. The distributed control system is composed of two modules: a scheduler and a coordinator, both implemented with neural networks. The control system enhances the local energy performance, scheduling the tasks demanded by the user and maximizing the use of local generation.

The history of technology in education. A comparative study and forecast

Area, launched in 1999 with the Bologna Declaration, has bestowed such a magnitude and unprecedented agility to the transformation process undertaken by European universities. However, the change has been more profound and drastic with regards to the use of new technologies both inside and outside the classroom. This article focuses on the study and analysis of the technology’s history within the university education and its impact on teachers, students and teaching methods. All the elements that have been significant and innovative throughout the history inside the teaching process have been analyzed, from the use of blackboard and chalk during lectures, the use of slide projectors and transparent slides, to the use of electronic whiteboards and Internet nowadays. The study is complemented with two types of surveys that have been performed among teachers and students during the school years 1999 - 2011 in the School of Civil Engineering at the Polytechnic University of Madrid. The pros and cons of each of the techniques and methodologies used in the learning process over the last decades are described, unfolding how they have affected the teacher, who has evolved from writing on a whiteboard to project onto a screen, the student, who has evolved from taking handwritten notes to download information or search the Internet, and the educational process, that has evolved from the lecture to acollaborative learning and project-based learning. It is unknown how the process of learning will evolve in the future, but we do know the consequences that some of the multimedia technologies are having on teachers, students and the learning process. It is our goal as teachers to keep ourselves up to date, in order to offer the student adequate technical content, while providing proper motivation through the use of new technologies. The study provides a forecast in the evolution of multimedia within the classroom and the renewal of the education process, which in our view, will set the basis for future learning process within the context of this new interactive era.

Applying foresight tools to determine future demand requirements on tourist destinations

Applying foresight tools to determine future demand requirements on tourist destinations

Economics and forecast of energy consumption in NGN networks: the case of Spain

Reducing energy consumption is one of the main goals of sustainability planning in most countries. For instance in Europe, the EC established the objectives in the Communication “20 20 by 2020 Europe's climate change opportunity”.

Energy Consumption Forecast in 4G Networks: The Case of Spain

Reducing energy consumption is one of the main goals of sustainability planning in most countries. For instance in Europe, the EC established the objectives in the Communication “20 20 by 2020 Europe's climate change opportunity”. • Next Generation Networks (NGN)  One of the most relevant upcoming ICT development • The role of energy consumption seems mostly absent from the main analysis and the debate on NGN deployment.

Architectures for Video-on-Demand content distribution in managed networks

La demanda de contenidos de vídeo ha aumentado rápidamente en los últimos años como resultado del gran despliegue de la TV sobre IP (IPTV) y la variedad de servicios ofrecidos por los operadores de red. Uno de los servicios que se ha vuelto especialmente atractivo para los clientes es el vídeo bajo demanda (VoD) en tiempo real, ya que ofrece una transmisión (streaming) inmediata de gran variedad de contenidos de vídeo. El precio que los operadores tienen que pagar por este servicio es el aumento del tráfico en las redes, que están cada vez más congestionadas debido a la mayor demanda de contenidos de VoD y al aumento de la calidad de los propios contenidos de vídeo. Así, uno de los principales objetivos de esta tesis es encontrar soluciones que reduzcan el tráfico en el núcleo de la red, manteniendo la calidad del servicio en el nivel adecuado y reduciendo el coste del tráfico. La tesis propone un sistema jerárquico de servidores de streaming en el que se ejecuta un algoritmo para la ubicación óptima de los contenidos de acuerdo con el comportamiento de los usuarios y el estado de la red. Debido a que cualquier algoritmo óptimo de distribución de contenidos alcanza un límite en el que no se puede llegar a nuevas mejoras, la inclusión de los propios clientes del servicio (los peers) en el proceso de streaming puede reducir aún más el tráfico de red. Este proceso se logra aprovechando el control que el operador tiene en las redes de gestión privada sobre los equipos receptores (Set-Top Box) ubicados en las instalaciones de los clientes. El operador se reserva cierta capacidad de almacenamiento y streaming de los peers para almacenar los contenidos de vídeo y para transmitirlos a otros clientes con el fin de aliviar a los servidores de streaming. Debido a la incapacidad de los peers para sustituir completamente a los servidores de streaming, la tesis propone un sistema de streaming asistido por peers. Algunas de las cuestiones importantes que se abordan en la tesis son saber cómo los parámetros del sistema y las distintas distribuciones de los contenidos de vídeo en los peers afectan al rendimiento general del sistema. Para dar respuesta a estas preguntas, la tesis propone un modelo estocástico preciso y flexible que tiene en cuenta parámetros como las capacidades de enlace de subida y de almacenamiento de los peers, el número de peers, el tamaño de la biblioteca de contenidos de vídeo, el tamaño de los contenidos y el esquema de distribución de contenidos para estimar los beneficios del streaming asistido por los peers. El trabajo también propone una versión extendida del modelo matemático mediante la inclusión de la probabilidad de fallo de los peers y su tiempo de recuperación en el conjunto de parámetros del modelo. Estos modelos se utilizan como una herramienta para la realización de exhaustivos análisis del sistema de streaming de VoD asistido por los peers para la amplia gama de parámetros definidos en los modelos. Abstract The demand of video contents has rapidly increased in the past years as a result of the wide deployment of IPTV and the variety of services offered by the network operators. One of the services that has especially become attractive to the customers is real-time Video on Demand (VoD) because it offers an immediate streaming of a large variety of video contents. The price that the operators have to pay for this convenience is the increased traffic in the networks, which are becoming more congested due to the higher demand for VoD contents and the increased quality of the videos. Therefore, one of the main objectives of this thesis is finding solutions that would reduce the traffic in the core of the network, keeping the quality of service on satisfactory level and reducing the traffic cost. The thesis proposes a system of hierarchical structure of streaming servers that runs an algorithm for optimal placement of the contents according to the users’ behavior and the state of the network. Since any algorithm for optimal content distribution reaches a limit upon which no further improvements can be made, including service customers themselves (the peers) in the streaming process can further reduce the network traffic. This process is achieved by taking advantage of the control that the operator has in the privately managed networks over the Set-Top Boxes placed at the clients’ premises. The operator reserves certain storage and streaming capacity on the peers to store the video contents and to stream them to the other clients in order to alleviate the streaming servers. Because of the inability of the peers to completely substitute the streaming servers, the thesis proposes a system for peer-assisted streaming. Some of the important questions addressed in the thesis are how the system parameters and the various distributions of the video contents on the peers would impact the overall system performance. In order to give answers to these questions, the thesis proposes a precise and flexible stochastic model that takes into consideration parameters like uplink and storage capacity of the peers, number of peers, size of the video content library, size of contents and content distribution scheme to estimate the benefits of the peer-assisted streaming. The work also proposes an extended version of the mathematical model by including the failure probability of the peers and their recovery time in the set of parameters. These models are used as tools for conducting thorough analyses of the peer-assisted system for VoD streaming for the wide range of defined parameters.

Caracterización de usuario y tráfico en la evolución de la banda ancha en España

El mundo de las telecomunicaciones evoluciona a gran velocidad, acorde con las necesidades de los usuarios. El crecimiento del número de servicios a través de las conexiones que actualmente utilizamos para conectarnos a Internet (Ej. IPTV) con elevados requerimientos de ancho de banda, que junto a los servicios de nuevo nacimiento (ej. OTT), contribuyen tanto al aumento de la necesidad de mayores velocidades de conexión de los usuarios como a la implantación de nuevos modelos de calidad de servicio. Las redes de datos de banda ancha (fija y móvil) actuales deben, por lo tanto, experimentar una profunda transformación para conseguir solventar de una forma eficiente los problemas y las necesidades de tráfico, pudiendo así absorber el progresivo incremento del ancho de banda, dejando las puertas abiertas a futuras mejoras. Y para ello las operadoras se nutrirán con la valiosa información de tráfico y usuario que les lleven a tomar las mejores decisiones de cara a que las transformaciones llevadas a cabo cubran exactamente lo que el usuario demanda de la forma más eficiente posible. Con estas premisas, surgieron las ideas que se plasmaron como objetivos del PFC : La idea de narrar el despliegue de la banda ancha en España desde sus orígenes hasta la actualidad, enfocando su crecimiento desde un punto de vista sociotecnológico. Dando continuidad al punto anterior, se persiguió la idea de conocer las herramientas sociales y tecnológicas a raíz de las cuales se pueda realizar una previsión del tráfico en las redes de las operadoras en un futuro cercano. La pretensión de mostrar las características de los usuarios de banda ancha y del tráfico de datos que generan, que son de carácter crítico para las operadoras en la elaboración de forma adecuada de la planificación de sus redes. La intención de revelar los procedimientos de las operadoras para que, una vez conocidas las características de sus usuarios, se puedan cumplir los requisitos demandados por los mismos: QoS y los indicadores clave de rendimiento (KPIs) Por otro lado, el nivel de detalle dado pretende adecuarse a un público que no tenga profundos conocimientos sobre la materia, y salvo partes bastante concretas, se puede catalogar este trabajo como de abierto al público en general. ABSTRACT. The world of telecommunications is evolving at high speed, according to the needs of users. The growing of services number through the connections that currently have been used to connect to the Internet (eg IPTV ) with high bandwidth requirements, which together with the new birth services (eg OTT ) contribute both to increased the need for higher connection speeds users and the implementation of new models of service quality. Data networks broadband (fixed and mobile ) today must , therefore, undergo a deep transformation to achieve an efficient solving problems and traffic needs, thus being able to absorb the gradual increase of bandwidth, leaving the door open to future improvements. And for that the operators will be nurtured with valuable information and user traffic that lead them to make better decisions in the face of the transformations carried out exactly meet the user demand for the most efficient possible way. With these assumptions, the ideas that emerged were expressed as PFC objectives : The idea of narrating the broadband deployment in Spain from its origins to the present, focusing its growth from a socio-technological approach. Continuing the previous point, it pursued the idea of knowing the social tools and technology as a result of which it can perform a traffic forecast operators networks in the near future. The attempt to show the characteristics of broadband users and data traffic they generate, which are mission critical for operators in developing adequately planning their networks. The intention to disclose procedures for operators, once known the characteristics of their users, it can meet the requirements demanded by them: QoS and key performance indicators (KPI). On the other hand, the level of detail given suit seeks an audience that does not have deep knowledge on the subject, unless quite specific parts, this work can be classified as open to the general public.

Contribution to energy consumption modelling and forecast in next generation access networks

La contribución del sector de las tecnologías de la información y las comunicaciones (TICs) al consumo de energía a nivel global se ha visto incrementada considerablemente en la última década al mismo tiempo que su relevancia dentro de la economía global. Se prevé que esta tendencia continúe debido al uso cada vez más intensivo de estas tecnologías. Una de las principales causas es el tráfico de datos de banda ancha generado por el uso de las redes de telecomunicaciones. De hecho como respuesta a esta demanda de recursos por parte de los usuarios, de la industria de las telecomunicaciones está iniciando el despliegue de las redes de nueva generación. En cualquier caso, el consumo de energía es un factor generalmente ausente del debate sobre el despliegue de estas tecnologías, a pesar de la posible repercusión que pueda llegar a tener en los costes y la sostenibilidad de estos proyectos. A lo largo de este trabajo se desarrollan modelos para evaluar el consumo energético de las redes de acceso de nueva generación (NGAN). Estos servirán tanto para llevar a cabo cálculos en un escenario global estático, como en cualquiera otro que determine la potencial evolución de la red de acceso a lo largo de su despliegue. Estos modelos combinan tres factores: la penetración prospectiva de cada una de las tecnologías de banda ancha analizadas, el tráfico generado por usuario y su futura evolución, y el perfil de consumo de energía de cada uno de los dispositivos de red desplegados. Tras evaluar los resultados derivados de la aplicación de los modelos en el caso demográfico específico de España, se obtienen conclusiones acerca de las diferencias tecnológicas en cuanto al consumo energético, sus implicaciones económicas, y la sensibilidad de los cálculos atendiendo a posibles modificaciones en los valores de referencia de diferentes parámetros de diseño. Se destaca por tanto el efecto en el consumo energético de los desarrollos tecnológicos, tecno-económicos, y de las decisiones en el ámbito regulatorio. Aunque como se ha dicho, se ha ejemplificado el cálculo para un caso particular, tanto los modelos como las conclusiones extraídas se pueden extrapolar a otros países similares.

Optimizing PV use through active demand side management

With recent technological developments within the field of power conditioning and the progressive decrease of incentives for PV electricity in grid-connected markets, new operation modes for PV systems should be explored beyond the traditional maximization of PV electri city feed-in. An example can be found in the domestic sector, where the use of modern PV hybrid systems combin ed with efficient electrical appliances and demand side management strategies can significantly enhance the PV value for the user. This paper presents an active demand side management system able to displace the consumer’s load curve in response to local (PV hybrid system, user) and external conditions (external grid). In this way, th e consumer becomes an “active consumer” that can also cooperate with others and the grid, increasing even more the PV value for the electrical system.