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
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
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 O with {\em ab initio} coupled-cluster theory
We present an \emph{ab initio} calculation of spectroscopic factors for
neutron and proton removal from 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 O states ,
, and , and proton removal spectroscopic factors for the
N states and . Our calculations support the accumulated
experimental evidence that 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
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
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
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
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
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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