18,246 research outputs found
Social Security and Well-Being of the Elderly: the Case of France
We use the 1982 and 1993 reforms of the French pension system in the private sector to study the relationship between Social Security benefits and the well-being of the elderly between the late 70s and the beginning of the new century. Affecting people in a different way, depending on year of birth, gender or socio-economic status, these reforms provide some sources of identification to estimate the effect of benefit changes on the standard of living of elderly families. To avoid spurious correlation or endogeneity problems in the determination of the impact of Social Security benefits on well-being we compute simulated social security payments and compare their evolution to various measures of well-being based on income, consumption, poverty, inequality or life satisfaction for both elderly and non-elderly families. We then focus on the 1982 and 1993 reforms. Our estimations conclude to a general increase in income, consumption and subjective well-being. However, a one euro increases in simulated benefit does not induce a one euro increase in after tax income (except at the top of the distribution), which shows some substitution between the different sources of income available for the elderly households. Estimation of difference in difference models to evaluate the impact on income and consumption of the 1982 and 1993 reforms underlines that it may exist asymmetry in the substitution effect between the different sources of income of the elderly depending on the sign of the change in generosity of the pension reforms.Retirement policies, Income, Poverty
New Technologies, Workplace Organisation and the Age Structure of the Workforce: Firm-Level Evidence
This paper investigates the relationships between new technologies, innovative workplace practices and the age structure of the workforce in a sample of French manufacturing firms. We find evidence that the wage bill share of older workers is lower in innovative firms and that the opposite holds for younger workers. This age bias is also evidenced within occupational groups, thus suggesting that skills do not completely protect workers against the labour market consequences of ageing. More detailed analysis of employment inflows and outflows shows that new technologies essentially affect older workers through reduced hiring opportunities, whereas organisational innovations mainly increase their probability of exit. This suggests that some skill obsolescence may be at work in our sample.new work practices, technology, older workers, labour demand
Phase transitions and quantum measurements
In a quantum measurement, a coupling between the system S and the
apparatus A triggers the establishment of correlations, which provide
statistical information about S. Robust registration requires A to be
macroscopic, and a dynamical symmetry breaking of A governed by S allows the
absence of any bias. Phase transitions are thus a paradigm for quantum
measurement apparatuses, with the order parameter as pointer variable. The
coupling behaves as the source of symmetry breaking. The exact solution of
a model where S is a single spin and A a magnetic dot (consisting of
interacting spins and a phonon thermal bath) exhibits the reduction of the
state as a relaxation process of the off-diagonal elements of S+A, rapid due to
the large size of . The registration of the diagonal elements involves a
slower relaxation from the initial paramagnetic state of A to either one of its
ferromagnetic states. If is too weak, the measurement fails due to a
``Buridan's ass'' effect. The probability distribution for the magnetization
then develops not one but two narrow peaks at the ferromagnetic values. During
its evolution it goes through wide shapes extending between these values.Comment: 12 pages, 2 figure
The Quantum Measurement Process: Lessons from an Exactly Solvable Model
The measurement of a spin-\half is modeled by coupling it to an apparatus,
that consists of an Ising magnetic dot coupled to a phonon bath. Features of
quantum measurements are derived from the dynamical solution of the
measurement, regarded as a process of quantum statistical mechanics.
Schr\"odinger cat terms involving both the system and the apparatus, die out
very quickly, while the registration is a process taking the apparatus from its
initially metastable state to one of its stable final states. The occurrence of
Born probabilities can be inferred at the macroscopic level, by looking at the
pointer alone. Apparent non-unitary behavior of the measurement process is
explained by the arisal of small many particle correlations, that characterize
relaxation.Comment: 13 pages, discussion of pre-measurement added. World Scientific
style. To appear in proceedings "Beyond The Quantum", Th.M. Nieuwenhuizen et
al, eds, (World Scientific, 2007
Thomson's formulation of the second law: an exact theorem and limits of its validity
Thomson's formulation of the second law - no work can be extracted from a
system coupled to a bath through a cyclic process - is believed to be a
fundamental principle of nature. For the equilibrium situation a simple proof
is presented, valid for macroscopic sources of work. Thomson's formulation gets
limited when the source of work is mesoscopic, i.e. when its number of degrees
of freedom is large but finite. Here work-extraction from a single equilibrium
thermal bath is possible when its temperature is large enough. This result is
illustrated by means of exactly solvable models. Finally we consider the
Clausius principle: heat goes from high to low temperature. A theorem and some
simple consequences for this statement are pointed out.Comment: 6 pages Latex, uses aip-proceedings style files. Proceedings `Quantum
Limits to the Second Law', San Diego, July 200
Dichroism for orbital angular momentum using parametric amplification
We theoretically analyze parametric amplification as a means to produce dichroism based on the orbital angular momentum (OAM) of an incident signal field. The nonlinear interaction is shown to provide differential gain between signal states of differing OAM, the peak gain occurring at half the OAM of the pump field
Circular 73
An assessment of Growth of Infrastructure
Booms have been a common element in the development of frontier areas in the 19th and 20th
centuries. Most commonly, the booms have been associated with resource development such as the
mineral booms of the western United States. Booms usually involve some type of dramatic short-
term change which has wide-ranging implications (Gilmore, 1976).
Since the arrival of the Russians in Alaska, six major booms have occurred: furs, whales,
salmon, minerals, military, and petroleum. Each of these booms has, to some degree, created changes
in the landscape of Alaska, in particular, the infrastructural base, which in turn has facilitated subsequent development, either another major boom, or a smaller development. For example, agricultural
development has been enhanced by mineral, military, and petroleum booms in Alaska. The cumulative impact on infrastructure of more than one boom, or multibooms, as it is referred to here, is the
focus of this paper.
One problem encountered in studying booms is that there is no general agreement on what
constitutes a boom. Detailed studies of booms in communities such as Dixon’s (1978) analysis of
Fairbanks and Gilmore’s multi-community work in the Great Plains—Rocky •mountain regions,
contained no specific definition of the term “boom”. Yet it was clear in each study that something
dramatic had occurred. More general historical studies of the Western mineral bonanzas (Greever,
1963) or the Klondike gold rush (Berton, 1958) likewise suggest a number of factors such as population rise, influx of money, resource extraction, and infrastructure expansion. But in each case, there
is no specific factor or define rate of something that specifically qualifies a time period as a boom. In
this study, we are concerned with dramatic change of events which have had a major impact on the
geographic landscape of an area, As a framework for the initial study, we review those events which
have been given attention as boom-type activities in the historical literature of Alaska (Rogers, 1962;
Naske and Slotnick, 1987)
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