506 research outputs found
Self-esteem achievement through work and socio-demographic disparities in the labor market
We develop a model in which agents choose whether to achieve self-esteem through work. When they do, they develop an intrinsic motivtion to effort. Depending on the characteristics of the job to be filled, an employer may try, or not, to encourage this intrinsic motivation by an adequately designed contract. Although equally productive, assuming that agents from distinct socio-demographic groups differ in their propensity to achieve self-esteem through work, this may lead to unequal access to employment. We analyse the consequences of this model on labor market outcomes. The model can give an account of many important traits of socio-demographic disparities in the labor market (notably of vertical occupational segregation.Employment relation, self-esteem, intrinsic motivation, (seeming) hiring discrimination, occupational segregation, socio-demographic earnings gaps.
Understanding socio-demographic disparities in the labor market : the case for a motivation-based theory
This paper puts the empirical case for a motivation-based theory of socio-demographic disparities in the labor market. We first present the basic knowledge as regards earnings disparities in the labor market and sum up the classic assessment of the theoretical literature focusing on pure pay discrimination. We then make an attempt to demonstrate that the relevant issues as regards socio-demographic disparities in the labor market, are rather hiring discrimination and, above all, occupational segregation. In this spirit, we have provided in an early work a motivation-based theory of hiring discrimination suggesting a particular pattern of socio-demographic occupational segregation. We check what our model suggests both against statistical and micro evidence. We end with a discussion of the links between our approach and dominant existing theories.Occupational segregation, hiring discrimination, earnings gap
Meta-dynamical adaptive systems and their applications to a fractal algorithm and a biological model
In this article, one defines two models of adaptive systems: the
meta-dynamical adaptive system using the notion of Kalman dynamical systems and
the adaptive differential equations using the notion of variable dimension
spaces. This concept of variable dimension spaces relates the notion of spaces
to the notion of dimensions. First, a computational model of the Douady's
Rabbit fractal is obtained by using the meta-dynamical adaptive system concept.
Then, we focus on a defense-attack biological model described by our two
formalisms
Self-esteem achievement through work and socio-demographic disparities in the labor market
URL des Cahiers : https://halshs.archives-ouvertes.fr/CAHIERS-MSECahiers de la Maison des Sciences Economiques 2005.65 - ISSN : 1624-0340We develop a model in which agents choose whether to achieve self-esteem through work. When they do, they develop an intrinsic motivtion to effort. Depending on the characteristics of the job to be filled, an employer may try, or not, to encourage this intrinsic motivation by an adequately designed contract. Although equally productive, assuming that agents from distinct socio-demographic groups differ in their propensity to achieve self-esteem through work, this may lead to unequal access to employment. We analyse the consequences of this model on labor market outcomes. The model can give an account of many important traits of socio-demographic disparities in the labor market (notably of vertical occupational segregation.Nous proposons un modèle au sein duquel des agents choisissent d'accéder à l'estime de soi par le travail ou par d'autres canaux. Quand ils choisissent d'accéder à l'estime de soi par le travail, ils développent une motivation intrinsèque à l'effort. Selon les caractéristiques de l'emploi qu'il cherche à pouvoir, un employeur peut chercher ou non à susciter une motivation intrinsèque en proposant un contrat adéquat. Bien qu'identiquement productifs, à supposer que des agents de groupes socio-demographiques distincts diffèrent dans leur propensité à rechercher l'estime de soi dans le travail, les arbitrages précédents peuvent conduire à un accès inégal à l'emploi. Nous analysons les conséquences de ce modèle sur le fonctionnement du marché du travail. Il peut rendre compte d'aspects important des disparités socio-démographiques sur le marché du travail (notamment d'une ségrégation verticale par activité)
Assessing optimal target populations for influenza vaccination programmes: an evidence synthesis and modelling study.
BACKGROUND: Influenza vaccine policies that maximise health benefit through efficient use of limited resources are needed. Generally, influenza vaccination programmes have targeted individuals 65 y and over and those at risk, according to World Health Organization recommendations. We developed methods to synthesise the multiplicity of surveillance datasets in order to evaluate how changing target populations in the seasonal vaccination programme would affect infection rate and mortality. METHODS AND FINDINGS: Using a contemporary evidence-synthesis approach, we use virological, clinical, epidemiological, and behavioural data to develop an age- and risk-stratified transmission model that reproduces the strain-specific behaviour of influenza over 14 seasons in England and Wales, having accounted for the vaccination uptake over this period. We estimate the reduction in infections and deaths achieved by the historical programme compared with no vaccination, and the reduction had different policies been in place over the period. We find that the current programme has averted 0.39 (95% credible interval 0.34-0.45) infections per dose of vaccine and 1.74 (1.16-3.02) deaths per 1,000 doses. Targeting transmitters by extending the current programme to 5-16-y-old children would increase the efficiency of the total programme, resulting in an overall reduction of 0.70 (0.52-0.81) infections per dose and 1.95 (1.28-3.39) deaths per 1,000 doses. In comparison, choosing the next group most at risk (50-64-y-olds) would prevent only 0.43 (0.35-0.52) infections per dose and 1.77 (1.15-3.14) deaths per 1,000 doses. CONCLUSIONS: This study proposes a framework to integrate influenza surveillance data into transmission models. Application to data from England and Wales confirms the role of children as key infection spreaders. The most efficient use of vaccine to reduce overall influenza morbidity and mortality is thus to target children in addition to older adults. Please see later in the article for the Editors' Summary
Capturing the time-varying drivers of an epidemic using stochastic dynamical systems
Epidemics are often modelled using non-linear dynamical systems observed
through partial and noisy data. In this paper, we consider stochastic
extensions in order to capture unknown influences (changing behaviors, public
interventions, seasonal effects etc). These models assign diffusion processes
to the time-varying parameters, and our inferential procedure is based on a
suitably adjusted adaptive particle MCMC algorithm. The performance of the
proposed computational methods is validated on simulated data and the adopted
model is applied to the 2009 H1N1 pandemic in England. In addition to
estimating the effective contact rate trajectories, the methodology is applied
in real time to provide evidence in related public health decisions. Diffusion
driven SEIR-type models with age structure are also introduced.Comment: 21 pages, 5 figure
Influenza interaction with cocirculating pathogens, and its impact on surveillance, pathogenesis and epidemic profile: a key role for mathematical modeling
ABSTRACT Evidence is mounting that influenza virus, a major contributor to the global disease burden, interacts with other pathogens infecting the human respiratory tract. Taking into account interactions with other pathogens may be critical to determining the real influenza burden and the full impact of public health policies targeting influenza. That necessity is particularly true for mathematical modeling studies, which have become critical in public health decision-making, despite their usually focusing on lone influenza virus acquisition and infection, thereby making broad oversimplifications regarding pathogen ecology. Herein, we review evidence of influenza virus interaction with bacteria and viruses, and the modeling studies that incorporated some of these. Despite the many studies examining possible associations between influenza and Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Neisseria meningitides , respiratory syncytial virus, human rhinoviruses, human parainfluenza viruses, etc., very few mathematical models have integrated other pathogens alongside influenza. A notable exception is the recent modeling of the pneumococcus-influenza interaction, which highlighted potential influenza-related increased pneumococcal transmission and pathogenicity. That example demonstrates the power of dynamic modeling as an approach to test biological hypotheses concerning interaction mechanisms and estimate the strength of those interactions. We explore how different interference mechanisms may lead to unexpected incidence trends and misinterpretations. Using simple transmission models, we illustrate how existing interactions might impact public health surveillance systems and demonstrate that the development of multipathogen models is essential to assess the true public health burden of influenza, and help improve planning and evaluation of control measures. Finally, we identify the public health needs, surveillance, modeling and biological challenges, and propose avenues of research for the coming years. Author Summary Influenza is a major pathogen responsible for important morbidity and mortality burdens worldwide. Mathematical models of influenza virus acquisition have been critical to understanding its epidemiology and planning public health strategies of infection control. It is increasingly clear that microbes do not act in isolation but potentially interact within the host. Hence, studying influenza alone may lead to masking effects or misunderstanding information on its transmission and severity. Herein, we review the literature on bacterial and viral species that interact with the influenza virus, interaction mechanisms, and mathematical modeling studies integrating interactions. We report evidence that, beyond the classic secondary bacterial infections, many pathogenic bacteria and viruses probably interact with influenza. Public health relevance of pathogen interactions is detailed, showing how potential misreading or a narrow outlook might lead to mistaken public health decisionmaking. We describe the role of mechanistic transmission models in investigating this complex system and obtaining insight into interactions between influenza and other pathogens. Finally, we highlight benefits and challenges in modeling, and speculate on new opportunities made possible by taking a broader view: including basic science, clinical relevance and public health
Stratégies d'accès à l'estime de soi et relation d'emploi
URL des Cahiers : https://halshs.archives-ouvertes.fr/CAHIERS-MSECahiers de la Maison des Sciences Economiques 2005.62 - ISSN : 1624-0340A model of employment relation is provided in which agents choose whether to seek self-esteem through work. When they do, they develop an intrinsic motivation to effort. Depending on non-wage characteristics of the job the employer wants to fill, she can encourage this intrinsic motivation by a well-designed contract. We show that the profitability as well as the efficiency of the employment relation may depend on non-wage gratification opportunities workers get.Nous proposons un modèle de relation d'emploi dans lequel les agents choisissent, ou non, d'accéder à l'estime de soi par le travail. Lorsque leur emploi est une source d'estime de soi, ils développent une motivation intrinsèque à l'effort. Selon les caractéristiques non-salariales de l'emploi qu'il cherche à pouvoir, un employeur peut chercher à susciter cette motivation intrinsèque en proposant le contrat adéquate. Nous montrons ainsi que la profitabilité et l'efficacité de la relation d'emploi peuvent dépendre des opportunités de gratification non-salariales qu'y puisent les travailleurs
Extending the elderly- and risk-group programme of vaccination against seasonal influenza in England and Wales: a cost-effectiveness study.
BACKGROUND: The present study aims to evaluate the cost-effectiveness of extending the pre-2013 influenza immunisation programme for high-risk and elderly individuals to those at low risk of developing complications following infection with seasonal influenza. METHODS: We performed an economic evaluation comparing different extensions of the pre-2013 influenza programme to seven possible age groups of low-risk individuals (aged 2-4 years, 50-64 years, 5-16 years, 2-4 and 50-64 years, 2-16 years, 2-16 and 50-64 years, and 2-64 years). These extensions are evaluated incrementally on four base scenarios (no vaccination, risk group only with coverage as observed between 1995 and 2009, risk group and 65+, and risk group with 75% coverage and 65+). Impact of vaccination is assessed using a transmission model built and parameterised from a previously published study. The study population is all individuals of all ages in England and Wales representing an average total of 52.6 million people over 14 influenza seasons (1995-2009). RESULTS: The influenza programme (risk group and elderly) prior to 2013 is likely to be cost effective (incremental cost effectiveness ratio: 7,475 £/QALY, net benefit: 253 M£ [15-829]). Extension to any one of the low-risk target groups defined earlier is likely to be cost-effective. However, strategies that do not include vaccination of school-aged children are less likely to be cost-effective. The most efficient strategy is extension to the 5-16 year age group while universal vaccination (extension to all low-risk individuals over 2 years) will achieve the highest net benefit. While extension to the 2-16 year age group is likely to be very cost effective, the cost-effectiveness of extensions beyond 2-16 years is very uncertain. Extension to the 5-16 year age group would likely remain cost-effective even without herd immunity effects to other age groups. As our study includes a strong historical component, our results depend on the efficacy of the influenza vaccine remaining at levels similar to the ones achieved in the past over a long-period of time (assumed to vary between 28% and 70% depending of the circulating strains and age groups). CONCLUSIONS: Making use of surveillance data from over a decade in conjunction with a dynamic model, we find that vaccination of children in the United Kingdom is likely to be highly cost-effective, not only for their own benefit but also to reduce the disease burden in the rest of the community
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