778 research outputs found

    Stochastic components of individual consumption: a time series analysis of grouped data

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    In this paper we propose a method to characterize the time series properties of individual consumption, income and interest rates using micro data, as studies in labour economics have characterized the time series properties of hours and earnings. Our approach, however, does not remove aggregate shocks. Having estimated the parameters of a flexible multivariate MA representation we relate the coefficients of our statistical model to structural parameters of theoretical models of consumption behaviour. Our approach offers a unifying framework that encompasses the Euler equation approach to the study of consumption and the studies that relate innovations to income to innovations to consumption, such as those that have found the so-called excess smoothness of consumption. Using a long time series of cross sections to construct synthetic panel data for the UK, we estimate our model and find that the restriction of Euler equations are typically not rejected, while the data show ‘excess smoothness’

    Image Analysis for Facility Siting: a Comparison of Lowand High-altitude Image Interpretability for Land Use/land Cover Mapping

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    For two test sites in Pennsylvania the interpretability of commercially acquired low-altitude and existing high-altitude aerial photography are documented in terms of time, costs, and accuracy for Anderson Level II land use/land cover mapping. Information extracted from the imagery is to be used in the evaluation process for siting energy facilities. Land use/land cover maps were drawn at 1:24,000 scale using commercially flown color infrared photography obtained from the United States Geological Surveys' EROS Data Center. Detailed accuracy assessment of the maps generated by manual image analysis was accomplished employing a stratified unaligned adequate class representation. Both 'area-weighted' and 'by-class' accuracies were documented and field-verified. A discrepancy map was also drawn to illustrate differences in classifications between the two map scales. Results show that the 1:24,000 scale map set was more accurate (99% to 94% area-weighted) than the 1:62,500 scale set, especially when sampled by class (96% to 66%). The 1:24,000 scale maps were also more time-consuming and costly to produce, due mainly to higher image acquisition costs

    Comparing activity and space patterns of the European pond turtle, Emys orbicularis (L., 1758) in a Venice Lagoon wetland area: implications for conservation planning and management

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    Behavioural and spatial distribution analyses were quantified during a phase of activity and lethargy in a wild population of the European pond turtle inhabiting a protected internal wetland area of the Venice lagoon. The marked individuals (13 males and 16 females) provided informative radiotracking data to study differential patterns of activity, dispersion and habitat use between the two study periods ("October-November both 2019 and 2020" and "June-July 2020"). The differences in the movements behaviours and habitat selection were affected by period. Movements were higher in the period of activity than lethargy, but they were not influenced by sex and size. The presence of the European pond turtle in the transitional woodland/shrubs and brackish water valley habitats was significantly higher in the period of activity than lethargy. During the latter one, pond turtles were observed to brumate gregariously in a small area for brumation, usually in shallow water. In contrast, all individuals have changed water bodies during the activity period. Part of those movements has occurred towards aquatic habitat with higher salinities 1-17%o (mean: 10.64%o). These findings provide a set of information to better understand the behavioural ecology of Emys orbicularis in the lagoon area. This is of relevance for management actions and for the conservation of this threatened species

    A Study of the Pyrolysis Products of Kraft Lignin

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    In order to valorize lignin wastes to produce useful aromatic compounds, the thermal degradation pyrolysis of Kraft lignin in the absence of catalysts has been investigated at 350, 450, and 550 \ub0C. The high content of sulfur in the fresh sample led to the formation of S\u2010containing compounds in products whose evolution in the gas phase was monitored through GC\u2010MS analysis. Py-rolytic gas is rich in CH4, CO, CO2, and H2S with the presence of other sulfur compounds in smaller amounts (i.e., CH3SH, CH3\u2010S\u2010CH3, SO2, COS, and CS2). Biochar morphology and elemental composition have been investigated by means of SEM and EDX. The carbon content reaches ~90% after pyrolysis at 550 \ub0C, while the oxygen content showed a decreasing trend with increasing tempera-ture. From GC\u2010MS analysis, bio\u2010oil resulted rich in alkyl\u2010alkoxy phenols, together with (alkyl)dihy-droxy benzenes and minor amounts of hydrocarbons and sulfur compounds. NaOH/H2O and EtOH/H2O extraction were performed with the aim of extracting phenolic\u2010like compounds. Sodium hydroxide solution allowed a better but still incomplete extraction of phenolic compounds, leaving a bio\u2010oil richer in sulfur

    Nearest transfer effects of working memory training: A comparison of two programs focused on working memory updating

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    This study analyzed the mechanisms involved in possible transfer effects for two different working memory updating (WMU) training programs administered to young adults and based on two updating paradigms: n-back and arithmetical updating. The influence of practice distribution on transfer effects was also explored by including two training regimens: massed and spaced practice. Performance on different WMU tasks more or less structurally similar to the tasks used in the training was assessed to analyze the nearest transfer effects. Near and far transfer effects were tested using complex working memory (WM) and fluid intelligence tasks. The results showed that the WMU training produced gains in only some of the WMU tasks structurally similar to those used in the training, not in those lacking the same structure, or in WM or fluid intelligence tasks. These limited nearest transfer effects suggest that gains could be due to the acquisition of a specific strategy appropriate for the task during the training rather than to any improvement in the updating process per se. Performance did not differ depending on the training regimen

    The aggregate implications of gender and marriage

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    Wages, labor market participation, hours worked, and savings differ by gender and marital status. In addition, women and married people make up a large fraction of the population and of labor market participants, total hours worked, and total earnings. For the most part, macroeconomists have been ignoring women and marriage in setting up structural models and in calibrating them using data on males only. In this paper, we ask whether ignoring gender and marriage in both models and data implies that the resulting calibration matches well the key economic aggregates. We find that it does not and we ask whether there are other calibration strategies or relatively simple models of marriage that can improve the fit of the model to aggregate data
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