Time-consistent consumption taxation

We characterise optimal fiscal policies when the government has access to consumption taxation but cannot credibly commit to future policies, in a calibrated Real Business Cycle model of the United States economy. Contrary to the case where only labour and capital income are taxed, the optimal time-consistent policies are remarkably similar to their Ramsey counterparts, as long as the capital income tax causes some distortion within the period. The welfare gains from commitment are negligible, while they are substantial without consumption taxation. Further, the welfare gains from taxing consumption are much higher without commitment. These results suggest that the policy-maker's ability to commit is of secondary importance if consumption is taxed optimally

Analysis of the perturbations in the angular orbital elements for the satellite Relay 2

Perturbation analysis for angular orbital elements of Relay 2 satellit

Pareto-Improving Optimal Capital and Labor Taxes

We study Pareto-optimal scal policy in a model with agents who are heterogeneous in their labor productivity and wealth. We show a natural modi cation of the standard Ramsey problem to guarantee that long-run capital taxes are zero. We focus on Paretoimproving policies and we nd that a gradual reform is crucial in achieving a Pareto improvement: labor taxes should be cut and capital taxes should remain high for a very long time before reaching zero. Therefore, the long-run optimal tax mix is the opposite of the short- and medium-run one. This policy redistributes wealth in favor of workers so that all agents bene t, and it favors quick capital growth after the reform. The labor tax cut is nanced by de cits which lead to a positive level of government debt in the long run, reversing the standard prediction that the government accumulates savings in models with optimal capital taxes. The welfare bene ts from the tax reform are relatively large and they can be shifted entirely to capitalists or workers by varying the length of the transition. We address a number of technical issues such as su ciency of Lagrangian solutions in a Ramsey problem, relation of Pareto-improving allocations with welfare functions, asymptotic behavior, and solution algorithms

MEASUREMENT OF KINEMATIC PARAMETERS OF RUNNING

The contribution gives information about the device for kinematic parameters of running (contact and flight time, stride length and time of measured distance). The principle of measurement is based on time measurement of connected and nonconnected electric circuit and at the same time the length of run distances is measured. The final time of measured distance is gained by measurement of stated number of impulses from the length scanner. The device can be used as the means of speed abilities testing in sport training. It is used for search of talents in athletic sprints and jumps and for measurement of time-and- space parameters of running of population with the aim to determine their developing characteristics

Efficient Risk Sharing with Limited Commitment and Storage

Revised version of the EUI ECO 2014/11We extend the model of risk sharing with limited commitment (Kocherlakota, 1996) by introducing both a public and a private (unobservable and/or non-contractible) storage technology. Positive public storage relaxes future participation constraints, hence it can improve risk sharing, contrary to the case where hidden income or effort is the deep friction. The characteristics of constrained-efficient allocations crucially depend on the storage technology’s return. In the long run, if the return on storage is (i) moderately high, both assets and the consumption distribution may remain time-varying; (ii) sufficiently high, assets converge almost surely to a constant and the consumption distribution is time-invariant; (iii) equal to agents’ discount rate, perfect risk sharing is self-enforcing. Agents never have an incentive to use their private storage technology, i.e., Euler inequalities are always satisfied, at the constrained-efficient allocation of our model, while this is not the case without optimal public asset accumulation. We compare the dynamics of consumption in simulated data and data from Indian villages, and find that past incomes matter in a similar way in our model with storage and the data but not in the basic limited-commitment model

Kinematische und dynamische Charakteristiken der maximalen Geschwindigkeit bei jungen Sprintern

Sprinting speed is a complex ability whose physiological basis is mostly genetically defined. Top competition results are therefore as a rile attainable only for a small, select number of individuals. The purpose of this study was to find the most important kinematic and dynamic parameters, their developmental trend and their influence on the efficiency in maximal sprinting speed for young sprinters of both sexes, from eleven to eighteen years of age. We recorded kinematic and dynamic parameters with locomometer. The vertical pressure on the surface was calculated by biomechanical modelling of running steps. We calculated correlation between maximal sprinting speed and Kinematic and dynamic parameters. The results show, for both sexes, that the structure of the sprint stride changes drastically in connection to the stride length and frequency, the ratio between the contact and the flight phases and the vertical pressure on the surface. The correlation coefficients show that the duration of contact (R=0.71), the relative stride frequency (R=0.52) and the vertical pressure on the surface (R=0.89) are good indicators of the sprinting potential of young runners.Brzina sprinta je kompleksna sposobnost čija se osnova većinom definira genetički. Vrhunske natjecateljske rezultati sloga u pravilu može postići samo mali broj odabranih pojedinaca. Svrha ovog istraživanja bila je naći najvažnije kinematičke i dinamičke parametre, njihov trend razvoja, te njihov utjecaj na efikasnost maksimalne brzine sprinta kod mladih sprintera oba spola, a ad 11 do 18 godina starosti. Kinematički i dinamički parametri snimani su lokomometrom. Okomiti pritisak na površinu izračunat je biomehaničkim modeliranjem trkaćih koraka. Izračunali smo korelaciju između maksimalne brzine sprinta, te kinematičkih j dinamičkih parametara. Rezultati pokazuju, za oba spola, da se struktura sprinterskog koraka drastično mijenja s obzirom na duljinu koraka i frekvenciju, omjer između faze kontakta i faze leta, te okomitog pritiska na površinu. Korelacijski koeficijenti pokazuju da su trajanje kontakta (R=0.71), relativna frekvencija koraka (R=0.52), te okomiti pritisak na površinu dobri (R=0.89) indikatori sprinterskog potencijala mladih sprintera.Die Geschwindigkeit des Sprints ist eine komplexe Fähigkeit, deren physiologische Basis meistens genetisch definiert wird. Spitzenwettkampfresultate sind deswegen in der Regel nur für eine geringe Anzahl von Sportlern erreichbar. Die Absicht dieser Forschung war die wichtigsten kinematischen und dynamischen Parameter zu finden, ihre Entwicklungstendenzen und ihr Einfluss auf die Effizienz bei der maximalen Geschwindigkeit des Sprints bei den jungen Sprintern beider Geschlechter im Alter von 11 bis 18 Jahre festzustellen. Wir haben die kinematischen und dynamischen Parameter mittels des Lokomometers aufgenommen. Der senkrechte Druck auf die Fläche wurde mittels der biomechanischen Modellierung von Laufschritten berechnet. Wir haben auch die Korrelation zwischen der maximalen Geschwindigkeit des Sprints und den kinematischen und dynamischen Parametern berechnet. Die Resultate zeigen, dass, für beide Geschlechter, die Struktur des Sprintschrittes bedeutend geändert wird in Bezug auf die Länge des Schrittes und die Frequenz, in Bezug auf das Verhältnis zwischen den Kontakt- und den Flugphasen als auch in Bezug auf den senkrechten Druck auf die Fläche. Die Korrelationskoeffiziente zeigen, dass die Dauer der Kontakt (R=0.71), die relative Schrittfrequenz (R=0.52) und der senkrechte Druck auf die Flache gute (R=0.89) Indikatoren des Sprintpotentials bei den jungen Läufern sind

Kinematische und dynamische Charakteristiken der maximalen Geschwindigkeit bei jungen Sprintern

Sprinting speed is a complex ability whose physiological basis is mostly genetically defined. Top competition results are therefore as a rile attainable only for a small, select number of individuals. The purpose of this study was to find the most important kinematic and dynamic parameters, their developmental trend and their influence on the efficiency in maximal sprinting speed for young sprinters of both sexes, from eleven to eighteen years of age. We recorded kinematic and dynamic parameters with locomometer. The vertical pressure on the surface was calculated by biomechanical modelling of running steps. We calculated correlation between maximal sprinting speed and Kinematic and dynamic parameters. The results show, for both sexes, that the structure of the sprint stride changes drastically in connection to the stride length and frequency, the ratio between the contact and the flight phases and the vertical pressure on the surface. The correlation coefficients show that the duration of contact (R=0.71), the relative stride frequency (R=0.52) and the vertical pressure on the surface (R=0.89) are good indicators of the sprinting potential of young runners.Brzina sprinta je kompleksna sposobnost čija se osnova većinom definira genetički. Vrhunske natjecateljske rezultati sloga u pravilu može postići samo mali broj odabranih pojedinaca. Svrha ovog istraživanja bila je naći najvažnije kinematičke i dinamičke parametre, njihov trend razvoja, te njihov utjecaj na efikasnost maksimalne brzine sprinta kod mladih sprintera oba spola, a ad 11 do 18 godina starosti. Kinematički i dinamički parametri snimani su lokomometrom. Okomiti pritisak na površinu izračunat je biomehaničkim modeliranjem trkaćih koraka. Izračunali smo korelaciju između maksimalne brzine sprinta, te kinematičkih j dinamičkih parametara. Rezultati pokazuju, za oba spola, da se struktura sprinterskog koraka drastično mijenja s obzirom na duljinu koraka i frekvenciju, omjer između faze kontakta i faze leta, te okomitog pritiska na površinu. Korelacijski koeficijenti pokazuju da su trajanje kontakta (R=0.71), relativna frekvencija koraka (R=0.52), te okomiti pritisak na površinu dobri (R=0.89) indikatori sprinterskog potencijala mladih sprintera.Die Geschwindigkeit des Sprints ist eine komplexe Fähigkeit, deren physiologische Basis meistens genetisch definiert wird. Spitzenwettkampfresultate sind deswegen in der Regel nur für eine geringe Anzahl von Sportlern erreichbar. Die Absicht dieser Forschung war die wichtigsten kinematischen und dynamischen Parameter zu finden, ihre Entwicklungstendenzen und ihr Einfluss auf die Effizienz bei der maximalen Geschwindigkeit des Sprints bei den jungen Sprintern beider Geschlechter im Alter von 11 bis 18 Jahre festzustellen. Wir haben die kinematischen und dynamischen Parameter mittels des Lokomometers aufgenommen. Der senkrechte Druck auf die Fläche wurde mittels der biomechanischen Modellierung von Laufschritten berechnet. Wir haben auch die Korrelation zwischen der maximalen Geschwindigkeit des Sprints und den kinematischen und dynamischen Parametern berechnet. Die Resultate zeigen, dass, für beide Geschlechter, die Struktur des Sprintschrittes bedeutend geändert wird in Bezug auf die Länge des Schrittes und die Frequenz, in Bezug auf das Verhältnis zwischen den Kontakt- und den Flugphasen als auch in Bezug auf den senkrechten Druck auf die Fläche. Die Korrelationskoeffiziente zeigen, dass die Dauer der Kontakt (R=0.71), die relative Schrittfrequenz (R=0.52) und der senkrechte Druck auf die Flache gute (R=0.89) Indikatoren des Sprintpotentials bei den jungen Läufern sind

Egocentric versus Allocentric Spatial Memory in Behavioral Variant Frontotemporal Dementia and Alzheimer's Disease

Background: Diagnosis of behavioural variant frontotemporal dementia (bvFTD) can be challenging, in particular when patients present with significant memory problems, which can increase the chance of a misdiagnosis of Alzheimer’s disease (AD). Growing evidence suggests spatial orientation is a reliable cognitive marker able to differentiate these two clinical syndromes. Objective: Assess the integrity of egocentric and allocentric heading orientation and memory in bvFTD and AD, and their clinical implications. Method: A cohort of 22 patient with dementia (11 bvFTD; 11 AD) and 14 healthy controls were assessed on the virtual supermarket task of spatial orientation and a battery of standardized neuropsychological measures of visual and verbal memory performance. Results: Judgements of egocentric and allocentric heading direction were differentially impaired in bvFTD and AD, with AD performing significantly worse on egocentric heading judgements than bvFTD. Both patient cohorts, however, showed similar degree of impaired allocentric spatial representation, and associated hippocampal pathology. Conclusions: The findings suggest egocentric heading judgements offer a more sensitive discriminant of bvFTD and AD than allocentric map-based measures of spatial memory

Lost in spatial translation - A novel tool to objectively assess spatial disorientation in Alzheimer's disease and frontotemporal dementia

Spatial disorientation is a prominent feature of early Alzheimer's disease (AD) attributed to degeneration of medial temporal and parietal brain regions, including the retrosplenial cortex (RSC). By contrast, frontotemporal dementia (FTD) syndromes show generally intact spatial orientation at presentation. However, currently no clinical tasks are routinely administered to objectively assess spatial orientation in these neurodegenerative conditions. In this study we investigated spatial orientation in 58 dementia patients and 23 healthy controls using a novel virtual supermarket task as well as voxel-based morphometry (VBM). We compared performance on this task with visual and verbal memory function, which has traditionally been used to discriminate between AD and FTD. Participants viewed a series of videos from a first person perspective travelling through a virtual supermarket and were required to maintain orientation to a starting location. Analyses revealed significantly impaired spatial orientation in AD, compared to FTD patient groups. Spatial orientation performance was found to discriminate AD and FTD patient groups to a very high degree at presentation. More importantly, integrity of the RSC was identified as a key neural correlate of orientation performance. These findings confirm the notion that i) it is feasible to assess spatial orientation objectively via our novel Supermarket task; ii) impaired orientation is a prominent feature that can be applied clinically to discriminate between AD and FTD and iii) the RSC emerges as a critical biomarker to assess spatial orientation deficits in these neurodegenerative conditions