Aggregate and welfare effects of long run inflation risk under inflation and price-level targeting

This paper presents a DSGE model in which long run inflation risk matters for social welfare. Aggregate and welfare effects of long run inflation risk are assessed under two monetary regimes: inflation targeting (IT) and price-level targeting (PT). These effects differ because IT implies base-level drift in the price level, while PT makes the price level stationary around a target price path. Under IT, the welfare cost of long run inflation risk is equal to 0.35 percent of aggregate consumption. Under PT, where long run inflation risk is largely eliminated, it is lowered to only 0.01 per cent. There are welfare gains from PT because it raises average consumption for the young and lowers consumption risk substantially for the old. These results are strongly robust to changes in the PT target horizon and fairly robust to imperfect credibility, fiscal policy, and model calibration. While the distributional effects of an unexpected transition to PT are sizeable, they are short-lived and not welfare-reducing.

Empirical testing of genuine savings as an indicator of weak sustainability: a three-country analysis of long run trends

Genuine Savings has emerged as a widely-used indicator of sustainable development. In this paper, we use long-term data stretching back to 1870 to undertake empirical tests of the relationship between Genuine Savings (GS) and future well-being for three countries: Britain, the USA and Germany. Our tests are based on an underlying theoretical relationship between GS and changes in the present value of future consumption. Based on both single country and panel results, we find evidence supporting the existence of a cointegrating (long run equilibrium) relationship between GS and future well-being, and fail to reject the basic theoretical result on the relationship between these two macroeconomic variables. This provides some support for the GS measure of weak sustainability. We also show the effects of modelling shocks, such as World War Two and the Great Depression.

Long-term effect of a school-based physical activity program (KISS) on fitness and adiposity in children: a cluster-randomized controlled trial.

BACKGROUND: School-based intervention studies promoting a healthy lifestyle have shown favorable immediate health effects. However, there is a striking paucity on long-term follow-ups. The aim of this study was therefore to assess the 3 yr-follow-up of a cluster-randomized controlled school-based physical activity program over nine month with beneficial immediate effects on body fat, aerobic fitness and physical activity. METHODS AND FINDINGS: Initially, 28 classes from 15 elementary schools in Switzerland were grouped into an intervention (16 classes from 9 schools, n = 297 children) and a control arm (12 classes from 6 schools, n = 205 children) after stratification for grade (1st and 5th graders). Three years after the end of the multi-component physical activity program of nine months including daily physical education (i.e. two additional lessons per week on top of three regular lessons), short physical activity breaks during academic lessons, and daily physical activity homework, 289 (58%) participated in the follow-up. Primary outcome measures included body fat (sum of four skinfolds), aerobic fitness (shuttle run test), physical activity (accelerometry), and quality of life (questionnaires). After adjustment for grade, gender, baseline value and clustering within classes, children in the intervention arm compared with controls had a significantly higher average level of aerobic fitness at follow-up (0.373 z-score units [95%-CI: 0.157 to 0.59, p = 0.001] corresponding to a shift from the 50th to the 65th percentile between baseline and follow-up), while the immediate beneficial effects on the other primary outcomes were not sustained. CONCLUSIONS: Apart from aerobic fitness, beneficial effects seen after one year were not maintained when the intervention was stopped. A continuous intervention seems necessary to maintain overall beneficial health effects as reached at the end of the intervention. TRIAL REGISTRATION: ControlledTrials.com ISRCTN15360785.

Bertrand and the long run

We propose a new model of simultaneous price competition, based on firms offering personalized prices to consumers. In a market for a homogeneous good and decreasing returns, the unique equilibrium leads to a uniform price equal to the marginal cost of each firm, at their share of the market clearing quantity. Using this result for the short-run competition, we then investigate the long-run investment decisions of the firms. While there is underinvestment, the overall outcome is more competitive than the Cournot model competition. Moreover, as the number of firms grows we approach the competitive long-run outcome.

Tracking cost savings from competitive tendering in the short and long run

A major initiative of the Thatcher and Major Conservative administrations was that public sector ancillary and professional services provided by incumbent direct service organisations [DSOs] be put out to tender. Analyses of this initiative, in the UK and elsewhere, found costs were often reduced in the short run. However, few if any studies went beyond the first round of tendering. We analyze data collected over successive rounds of tendering for cleaning and catering services of Scottish hospitals in order to assess the long term consequences of this initiative. The experience of the two services was very different. Cost savings for cleaning services tended to increase with each additional round of tendering and became increasingly stable. In accordance with previous results in the literature, DSOs produced smaller cost reductions than private contractors: probably an inevitable consequence of the tendering process at the time. Cost savings from DSOs tended to disappear during the first round of tendering, but they appear to have been more permanent in successive rounds. Cost savings for catering, on the other hand, tended to be much smaller, and these were not sustained.

A multi-purpose grammar generating a multi-scale integrated analysis of Laos

In this study we propose an application of the MuSIASEM approach which is used to provide an integrated analysis of Laos across different scales. With the term “integrated analysis across scales” we mean the generation of a series of packages of quantitative indicators, characterizing the performance of the socioeconomic activities performed in Laos when considering: (i) different hierarchical levels of organization (farming systems described at the level of household, rural villages, regions of Laos, the whole country level); and (ii) different dimensions of analysis (economic dimension, social dimension, ecological dimension, technical dimension). What is relevant in this application is that the information carried out by these different packages of indicators is integrated in a system of accounting which establishes interlinkages across these indicators. This is a essential feature to study sustainability trade-offs and to build more robust scenarios of possible changes. The multi-scale integrated representation presented in this study is based on secondary data (gathered in a three year EU project – SEAtrans and integrated by other available statistical sources) and it is integrated in GIS, when dealing with the spatial representation of Laos. However, even if we use data referring to Laos, the goal of this study is not that of providing useful information about a practical policy issue of Laos, but rather, to illustrate the possibility of using a multipurpose grammar to produce an integrated set of sustainability indicators at three different levels: (i) local; (ii) meso; (iii) macro level. The technical issue addressed is the simultaneous adoption of two multi-level matrices – one referring to a characterization of human activity over a set of different categories, and another referring to a characterization of land uses over the same set of categories. In this way, it becomes possible to explain the characteristics of Laos (an integrated set of indicators defining the performance of the whole country) in relation to the characteristics of the rural Laos and urban Laos. The characteristics of rural Laos, can be explained using the characteristics of three regions defined within Laos (Northern Laos, Central Laos and Southern Laos), which in turn can be defined (using an analogous package of indicators), starting from the characteristics of three main typologies of farming systems found in the regions.

A first attempt of geographically-distributed Multi-scale integrated analysis of societal and ecosystem metabolism (MuSIASEM): mapping human time and energy throughput in metropolitan Barcelona

This study presents a first attempt to extend the “Multi-scale integrated analysis of societal and ecosystem metabolism (MuSIASEM)” approach to a spatial dimension using GIS techniques in the Metropolitan area of Barcelona. We use a combination of census and commercial databases along with a detailed land cover map to create a layer of Common Geographic Units that we populate with the local values of human time spent in different activities according to MuSIASEM hierarchical typology. In this way, we mapped the hours of available human time, in regards to the working hours spent in different locations, putting in evidence the gradients in spatial density between the residential location of workers (generating the work supply) and the places where the working hours are actually taking place. We found a strong three-modal pattern of clumps of areas with different combinations of values of time spent on household activities and on paid work. We also measured and mapped spatial segregation between these two activities and put forward the conjecture that this segregation increases with higher energy throughput, as the size of the functional units must be able to cope with the flow of exosomatic energy. Finally, we discuss the effectiveness of the approach by comparing our geographic representation of exosomatic throughput to the one issued from conventional methods.

Anàlisi, disseny i implementació d'una eina de simulació per a l'estudi de la interoperabilitat mitjançant conversió d'atributs en entorns multi-domini

El present projecte part d’un estudi sobre el tractament de situacions d’emergència, on es considera que una infraestructura de comunicació, sobre aquest tipus d’escenaris, ha d’implementar la interoperabilitat i el control d’accés, entre els diferents elements que hi participen, utilitzant la conversió d’atributs. Per tal de materialitzar aquest estudi s’ha realitzat un anàlisi de les necessitats de l’aplicació i un disseny detallat dels mòduls que el formen. S’ha implementat d’aquesta manera una eina de simulació per entorns multi-domini. Finalment s’han realitzat un conjunt de proves per comprovar la seva fiabilitat respecte l’estudi original.

Gains from switching and evolutionary stability in multi-player matrix games.

In this paper we unify, simplify, and extend previous work on the evolutionary dynamics of symmetric N-player matrix games with two pure strategies. In such games, gains from switching strategies depend, in general, on how many other individuals in the group play a given strategy. As a consequence, the gain function determining the gradient of selection can be a polynomial of degree N-1. In order to deal with the intricacy of the resulting evolutionary dynamics, we make use of the theory of polynomials in Bernstein form. This theory implies a tight link between the sign pattern of the gains from switching on the one hand and the number and stability of the rest points of the replicator dynamics on the other hand. While this relationship is a general one, it is most informative if gains from switching have at most two sign changes, as is the case for most multi-player matrix games considered in the literature. We demonstrate that previous results for public goods games are easily recovered and extended using this observation. Further examples illustrate how focusing on the sign pattern of the gains from switching obviates the need for a more involved analysis.

Interfaz de usuario de un sistema multi-robot de reconocimiento de superficies con Google Earth

Els sistemes multi-robot de reconeixement de superfícies es poden utilitzar tant per a l'exploració de llocs remots, de difícil accés o perillosos. Normalment, els robots no són autònoms, depenen d'operadors humans per dirigir-los. La informació que capten ha de ser processada i mostrada a l'usuari o usuària del sistema de forma intel·ligible. Un exemple d'aplicació seria el d'un sistema multirobot format per diversos helicòpters no tripulats que proporciona informació d'una àrea que ha patit algun desastre. El sistema informàtic recolliria la informació i la transmetria al coordinador de l'operatiu d'assistència de l'emergència. La idea del projecte és la de combinar la informació proporcionada pel sistema multi-robot amb la de la zona disponible a Google Earth i fer d'aquesta eina l'interfície d'usuari de l'aplicació.

Análisis de prestaciones de procesadores multi-core y multi-thread

Los procesadores multi-core y el multi-threading por hardware permiten aumentar el rendimiento de las aplicaciones. Por un lado, los procesadores multi-core combinan 2 o más procesadores en un mismo chip. Por otro lado, el multi-threading por hardware es una técnica que incrementa la utilización de los recursos del procesador. Este trabajo presenta un análisis de rendimiento de los resultados obtenidos en dos aplicaciones, multiplicación de matrices densas y transformada rápida de Fourier. Ambas aplicaciones se han ejecutado en arquitecturas multi-core que explotan el paralelismo a nivel de thread pero con un modelo de multi-threading diferente. Los resultados obtenidos muestran la importancia de entender y saber analizar el efecto del multi-core y multi-threading en el rendimiento.

La prévention du suicide en milieu scolaire est-elle possible [Is it possible to run suicide prevention interventions within the school setting?]

Suicide represent the second cause of death in Switzerland and, between 15 and 20 years of age, 8% of girls and 4% of boys have attempted suicide at least once in their life. "Universal" primary prevention in schools is usually run through courses dealing with the issue of suicide and which are systematically provided to all pupils. There is no evidence that they have any positive effect and even they may be in some instances harmful. The training of professionals working in the school setting to better identify and refer adolescents facing risky situation is probably effective. Another promising approach is the one which aims at improving the school climate in increasing social connectedness and the pupils' life skills. Finally, the school which faces a suicide should set up debriefing activities, thus deterring vulnerable pupils to engage in violent acting as a result of a contamination process.