33 research outputs found

    Equity and Efficiency Measures of Tax-Transfer Systems: Some Evidence for New Zealand

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    The redistributive and efficiency aspects of personal taxes are of particular interest to both economists and governments designing tax reforms. Traditionally however, the numerous analytical tools available to calculate distributional and efficiency effects of taxes and transfers are not widely used in tax policy advice. This partly reflects the computational complexities involved in calculating some of those measures and the need for simplicity, and transparency of underlying assumptions, when presenting policy advice. This paper makes two contributions to the analysis of the equity and efficiency effects of tax policy. Firstly, it applies the methodologies proposed by economists to measure equity and efficiency outcomes of taxes to provide some evidence for the New Zealand income tax and transfer system. This makes use of Treasury’s microsimulation model, TaxWell. Secondly, the paper examines a database of low-income New Zealand taxpayers. A decomposition by individual and household characteristics shows that different groups of low income taxpayers can be affected quite differently by various aspects of the tax/transfer system. In particular, tax-free zones do not appear well targeted to help those most in need.Personal Income Taxes; Equity; Redistribution; Transfers; Tax Efficiency

    Grasses as Biofactories: Scoping out the Opportunities

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    Key points 1. Plant biopharming is set to dominate commercial recombinant protein expression for specific proteins. 2. The choice of plant species depends on a multitude of factors and is determined on a caseby- case basis. 3. As a leaf based expression system grasses would have to compete predominantly with tobacco and alfalfa. 4. The grass-endophyte symbiosis offers a number of unique possibilities for biopharming

    Grasses as Biofactories: Scoping out the Opportunities

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    Plant biopharming is set to dominate commercial recombinant protein expression for specific proteins. The choice of plant species depends on a multitude of factors and is determined on a case- by-case basis. As a leaf based expression system grasses would have to compete predominantly with tobacco and alfalfa. The grass-endophyte symbiosis offers a number of unique possibilities for biopharming

    Effect of topography on subglacial discharge and submarine melting during tidewater glacier retreat.

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    -We explored secular variations in subglacial discharge and submarine melting with an idealized model -Subglacial discharge increases as tidewater glaciers retreat along retrograde beds -Submarine melting depends on subglacial discharge and therefore promotes unstable retreat on retrograde bedsTo first order, subglacial discharge depends on climate, which determines precipitation fluxes and glacier mass balance, and the rate of glacier volume change. For tidewater glaciers, large and rapid changes in glacier volume can occur independent of climate change due to strong glacier dynamic feedbacks. Using an idealized tidewater glacier model, we show that these feedbacks produce secular variations in subglacial discharge that are influenced by subglacial topography. Retreat along retrograde bed slopes (into deep water) results in rapid surface lowering and coincident increases in subglacial discharge. Consequently, submarine melting of glacier termini, which depends on subglacial discharge and ocean thermal forcing, also increases during retreat into deep water. Both subglacial discharge and submarine melting subsequently decrease as glacier termini retreat out of deep water and approach new steady state equilibria. In our simulations, subglacial discharge reached peaks that were 6–17% higher than preretreat values, with the highest values occurring during retreat from narrow sills, and submarine melting increased by 14% for unstratified fjords and 51% for highly stratified fjords. Our results therefore indicate that submarine melting acts in concert with iceberg calving to cause tidewater glacier termini to be unstable on retrograde beds. The full impact of submarine melting on tidewater glacier stability remains uncertain, however, due to poor understanding of the coupling between submarine melting and iceberg calving.Funding was provided by the National Oceanic and Atmospheric Association (NA13OAR4310098) and the U.S. National Science Foundation (PLR-1504288 and PLR-1504521).Ye

    The Classification and Evolution of Bacterial Cross-Feeding

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    Bacterial feeding has evolved toward specific evolutionary niches and the sources of energy differ between species and strains. Although bacteria fundamentally compete for nutrients, the excreted products from one strain may be the preferred energy source or a source of essential nutrients for another strain. The large variability in feeding preferences between bacterial strains often provides for complex cross-feeding relationships between bacteria, particularly in complex environments such as the human lower gut, which impacts on the host's digestion and nutrition. Although a large amount of information is available on cross-feeding between bacterial strains, it is important to consider the evolution of cross-feeding. Adaptation to environmental stimuli is a continuous process, thus understanding the evolution of microbial cross-feeding interactions allows us to determine the resilience of microbial populations to changes to this environment, such as changes in nutrient supply, and how new interactions might emerge in the future. In this review, we provide a framework of terminology dividing bacterial cross-feeding into four forms that can be used for the classification and analysis of cross-feeding dynamics. Under the proposed framework, we discuss the evolutionary origins for the four forms of cross-feeding and factors such as spatial structure that influence their emergence and subsequent persistence. This review draws from both the theoretical and experimental evolutionary literature to provide a cross-disciplinary perspective on the evolution of different types of cross-feeding

    Estimating cropland requirements for global food system scenario modeling

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    IntroductionThe production of plant crops is foundational to the global food system. With the need for this system to become more sustainable while feeding an increasing global population, tools to investigate future food system scenarios can be useful to aid decision making, but are often limited to a calorie- or protein-centric view of human nutrition.MethodsHere, a mathematical model for forecasting the future cropland requirement to produce a given quantity of crop mass is presented in conjunction with the DELTA Model®: an existing food system scenario model calculating global availability of 29 nutrients against human requirements. The model uses national crop yield data to assign yield metrics for 137 crops.ResultsThe crops with the greatest variation between high and low yielding production were specific nuts, fruits, and vegetables of minor significance to global nutrient availability. The nut crop group showed the greatest overall yield variation between countries, and thus the greatest uncertainty when forecasting the cropland requirement for future increases in production. Sugar crops showed the least overall yield variation. The greatest potential for increasing global food production by improving poor yielding production was found for the most widely grown crops: maize, wheat, and rice, which were also demonstrated to be of high nutritional significance.DiscussionThe combined cropland and nutrient availability model allowed the contribution of plant production to global nutrition to be quantified, and the cropland requirement of future food production scenarios to be estimated. The unified cropland estimation and nutrient availability model presented here is an intuitive and broadly applicable tool for use in global food system scenario modeling. It should benefit future research and policy making by demonstrating the implications for human nutrition of changes to crop production, and conversely the implications for cropland requirement of food production scenarios aimed at improving nutrition

    Subglacial discharge at tidewater glaciers revealed by seismic tremor

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    Subglacial discharge influences glacier basal motion and erodes and redeposits sediment. At tidewater glacier termini, discharge drives submarine terminus melting, affects fjord circulation, and is a central component of proglacial marine ecosystems.Subglacial discharge influences glacier basal motion and erodes and redeposits sediment. At tidewater glacier termini, discharge drives submarine terminus melting, affects fjord circulation, and is a central component of proglacial marine ecosystems. However, our present inability to track subglacial discharge and its variability significantly hinders our understanding of these processes. Here we report observations of hourly to seasonal variations in 1.5–10 Hz seismic tremor that strongly correlate with subglacial discharge but not with basal motion, weather, or discrete icequakes. Our data demonstrate that vigorous discharge occurs from tidewater glaciers during summer, in spite of fast basal motion that could limit the formation of subglacial conduits, and then abates during winter. Furthermore, tremor observations and a melt model demonstrate that drainage efficiency of tidewater glaciers evolves seasonally. Glaciohydraulic tremor provides a means by which to quantify subglacial discharge variations and offers a promising window into otherwise obscured glacierized environments.We thank the U.S. National Science Foundation for supporting data collection at Yahtse Glacier through grant EAR-0810313. T.C.B. was substantially supported by a postdoctoral fellowship from the University of Texas Institute for Geophysics. J.M.A. was supported by Alaska NASA EPSCoR Program (NNX13AB28A). S.O. was supported by the U.S. Geological Survey Climate and Land Use Change Mission and the U.S. Department of Interior Alaska Climate Science Center. Seismic instrumentationwas provided by the PASSCAL polar program of the Incorporated Research Institutions for Seismology (IRIS). Jamie Bradshaw and Marci Beitch assisted in the Mendenhall Glacier data collection effort. Two anonymous reviewers helped to improve the manuscript. Seismic data used in this study are archived at the Incorporated Research Institutions for Seismology Data Management Center (IRIS DMC, http://www.iris.edu/dms/nodes/dmc/). Stream gaging data for the Mendenhall River and Nugget Creek are available though http://waterdata.usgs.gov/ak/nwis/dv/?site_no=15052500 and http://waterdata.usgs.gov/ak/nwis/dv/?site_no=15052495. Any additional data may be obtained from T.C.B. ([email protected]). Use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. The Editor thanks Gordon Hamilton and an anonymous reviewer for their assistance in evaluating this paper.Ye

    A surveillance sector review applied to infectious diseases at a country level

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    <p>Abstract</p> <p>Background</p> <p>The new International Health Regulations (IHR) require World Health Organization (WHO) member states to assess their core capacity for surveillance. Such reviews also have the potential to identify important surveillance gaps, improve the organisation of disparate surveillance systems and to focus attention on <it>upstream </it>hazards, determinants and interventions.</p> <p>Methods</p> <p>We developed a <it>surveillance sector review </it>method for evaluating all of the surveillance systems and related activities across a sector, in this case those concerned with infectious diseases in New Zealand. The first stage was a systematic description of these surveillance systems using a newly developed framework and classification system. Key informant interviews were conducted to validate the available information on the systems identified.</p> <p>Results</p> <p>We identified 91 surveillance systems and related activities in the 12 coherent categories of infectious diseases examined. The majority (n = 40 or 44%) of these were disease surveillance systems. They covered all categories, particularly for more severe outcomes including those resulting in death or hospitalisations. Except for some notifiable diseases and influenza, surveillance of less severe, but important infectious diseases occurring in the community was largely absent. There were 31 systems (34%) for surveillance of <it>upstream </it>infectious disease hazards, including risk and protective factors. This area tended to have many potential gaps and lack integration, partly because such systems were operated by a range of different agencies, often outside the health sector. There were fewer surveillance systems for determinants, including population size and characteristics (n = 9), and interventions (n = 11).</p> <p>Conclusions</p> <p>It was possible to create and populate a workable framework for describing all the infectious diseases surveillance systems and related activities in a single developed country and to identify potential surveillance sector gaps. This is the first stage in a review process that will lead to identification of priorities for surveillance sector development.</p

    Contemporaneity of Clactonian and Acheulean flint industries at Barnham, Suffolk

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    New field evidence challenges an old-established fundamental of the Lower Palaeolithic sequence in Britain

    Bifaces in perspective

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