81,889 research outputs found

    The Taxman Tools Up: An Event History Study of the Introduction of the Personal Income Tax in Western Europe, 1815 - 1941

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    The introduction of income taxation was a landmark in the development of the fiscal state in Western Europe and elsewhere. This paper presents an event history study of the adoption of the income tax in 11 Western European countries between 1815 and 1941. We find evidence that social learning, reductions in tax collection costs and to a lesser extend spending pressures played a significant role for the adoption decision. Surprisingly, we also find evidence that the extension of the franchise reduced the likelihood of adoption of the income tax

    In field N transfer, build-up, and leaching in ryegrass-clover mixtures

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    Two field experiments investigating dynamics in grass-clover mixtures were conducted, using 15N- and 14C-labelling to trace carbon (C) and nitrogen (N) from grass (Lolium perenne L.) and clover (Trifolium repens L. and Trifolium pratense L.). The leaching of dissolved inorganic nitrogen (DIN), as measured in pore water sampled by suction cups, increased during the autumn and winter, whereas the leaching of dissolved organic nitrogen (DON) was fairly constant during this period. Leaching of 15N from the sward indicated that ryegrass was the direct source of less than 1-2 percent of the total N leaching measured, whereas N dynamics pointed to clover as an important contributor to N leaching. Sampling of roots indicates that the dynamics in smaller roots were responsible for N and C build-up in the sward, and that N became available for transfer among species and leaching from the root zone. The bi-directional transfer of N between ryegrass and clover could however not be explained only by root turnover. Other processes like direct uptake of organic N compounds, may have contributed

    Closed-shell properties of 24^{24}O with {\em ab initio} coupled-cluster theory

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    We present an \emph{ab initio} calculation of spectroscopic factors for neutron and proton removal from 24^{24}O using the coupled-cluster method and a state-of-the-art chiral nucleon-nucleon interaction at next-to-next-to-next-to-leading order. In order to account for the coupling to the scattering continuum we use a Berggren single-particle basis that treats bound, resonant, and continuum states on an equal footing. We report neutron removal spectroscopic factors for the 23^{23}O states Jπ=1/2+J^{\pi} = 1/2^+, 5/2+5/2^+, 3/2−3/2^- and 1/2−1/2^-, and proton removal spectroscopic factors for the 23^{23}N states 1/2−1/2^- and 3/2−3/2^-. Our calculations support the accumulated experimental evidence that 24^{24}O is a closed-shell nucleus.Comment: 5 pages, 2 figures, 1 tabl

    A Density-Based Approach to the Retrieval of Top-K Spatial Textual Clusters

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    Keyword-based web queries with local intent retrieve web content that is relevant to supplied keywords and that represent points of interest that are near the query location. Two broad categories of such queries exist. The first encompasses queries that retrieve single spatial web objects that each satisfy the query arguments. Most proposals belong to this category. The second category, to which this paper's proposal belongs, encompasses queries that support exploratory user behavior and retrieve sets of objects that represent regions of space that may be of interest to the user. Specifically, the paper proposes a new type of query, namely the top-k spatial textual clusters (k-STC) query that returns the top-k clusters that (i) are located the closest to a given query location, (ii) contain the most relevant objects with regard to given query keywords, and (iii) have an object density that exceeds a given threshold. To compute this query, we propose a basic algorithm that relies on on-line density-based clustering and exploits an early stop condition. To improve the response time, we design an advanced approach that includes three techniques: (i) an object skipping rule, (ii) spatially gridded posting lists, and (iii) a fast range query algorithm. An empirical study on real data demonstrates that the paper's proposals offer scalability and are capable of excellent performance

    Efficient Management of Short-Lived Data

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    Motivated by the increasing prominence of loosely-coupled systems, such as mobile and sensor networks, which are characterised by intermittent connectivity and volatile data, we study the tagging of data with so-called expiration times. More specifically, when data are inserted into a database, they may be tagged with time values indicating when they expire, i.e., when they are regarded as stale or invalid and thus are no longer considered part of the database. In a number of applications, expiration times are known and can be assigned at insertion time. We present data structures and algorithms for online management of data tagged with expiration times. The algorithms are based on fully functional, persistent treaps, which are a combination of binary search trees with respect to a primary attribute and heaps with respect to a secondary attribute. The primary attribute implements primary keys, and the secondary attribute stores expiration times in a minimum heap, thus keeping a priority queue of tuples to expire. A detailed and comprehensive experimental study demonstrates the well-behavedness and scalability of the approach as well as its efficiency with respect to a number of competitors.Comment: switched to TimeCenter latex styl

    Pareto Efficiency, Relative Prices, and Solutions to CGE Models

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    This paper analyzes Walrasian general equilibrium systems and calculates the static and dynamic solutions for competitive market equilibria. The Walrasian framework encompasses the basic multi-sector growth (MSG) models with neoclassical production technologies in N sectors (industries). The endogenous behavior of all relative prices and the sectorial allocation of the two primary factors (labor and capital) are analyzed in detail. The dynamic systems of Walrasian multi-sector economies and the family of solutions (time paths) for steady-state and persistent growth per capita are parametrically characterized. The technology parameters of the capital good industry are decisive for obtaining long-run per capita growth in closed (global) economies. Brief comments on the MSG literature are offered, together with short remarks on studies of industrial (structural) evolution and economic history.

    Collisional deexcitation of exotic hydrogen atoms in highly excited states. II. Cascade calculations

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    The atomic cascades in mu-p and pbar-p atoms have been studied in detail using new results for the cross-sections of the scattering of highly excited exotic atoms from molecular hydrogen. The cascade calculations have been done with an updated version of the extended standard cascade model that computes the evolution in the kinetic energy from the beginning of the cascade. The resulting X-ray yields, kinetic energy distributions, and cascade times are compared with the experimental data.Comment: 13 pages, 23 figure

    Collisional deexcitation of exotic hydrogen atoms in highly excited states. I. Cross-sections

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    The deexcitation of exotic hydrogen atoms in highly excited states in collisions with hydrogen molecules has been studied using the classical-trajectory Monte Carlo method. The Coulomb transitions with large change of principal quantum number n have been found to be the dominant collisional deexcitation mechanism at high n. The molecular structure of the hydrogen target is shown to be essential for the dominance of transitions with large \Delta n. The external Auger effect has been studied in the eikonal approximation. The resulting partial wave cross-sections are consistent with unitarity and provide a more reliable input for cascade calculations than the previously used Born approximation.Comment: 10 pages, 20 figure
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