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 $g$ 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 $g$ 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 $N$ 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 $N$. 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 $g$ 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)