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Página 1 dos resultados de 47 itens digitais encontrados em 0.040 segundos

- Universidade de Évora
- Genetics Society of America
- Public Library of Science
- Instituto Universitário Europeu
- Universidad de ICESI. Departamento de Economía
- World Bank, Washington, DC
- Universidade Cornell
- Royal Astronomical Society
- EDP Sciences
- Universidade de São Paulo. Faculdade de Economia, Administração e Contabilidade
- Suntory and Toyota International Centres for Economics and Related Disciplines, London School of Economics and Political Science
- Mais Publicadores...

## ‣ Evidence on Gender Wage Discrimination in Portugal: parametric and semi-parametric approaches

Fonte: Universidade de Évora
Publicador: Universidade de Évora

Tipo: Trabalho em Andamento

Português

Relevância na Pesquisa
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In this paper we use two alternative approaches to study the extent of gender wage discrimination in Portugal. Both methods involve the estimation of wage equations for males and females and the Blinder [1973] and Oaxaca [1973] decomposition. However, to take into account possible sample selection bias, we consider both parametric and semi-parametric methods. First, we consider a parametric approach that relies on distributional assumptions about the distribution of the error terms in the model (Vella (1992, 1998) and Wooldridge (1998)). Within this approach, if the distributional assumption is not satisfied, the parameters’ estimates may be inconsistent. Secondly, we apply Li and Wooldridge [2002] semi-parametric estimator, which does not assume any known distribution on the joint distribution of the errors of the wage equation and of the sample selection equation; the distribution has an unknown form and is estimated through non-parametric kernel techniques.We employ micro data for Portugal from the European Community Household Panel (ECHP). The results from both approaches provide evidence in favour of the existence of gender wage discrimination in Portugal. However, the extent of labour market discrimination decreases when sample selection bias corrections are taken into account.

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## ‣ Estimating the Parameters of Selection on Nonsynonymous Mutations in Drosophila pseudoobscura and D. miranda

Fonte: Genetics Society of America
Publicador: Genetics Society of America

Tipo: Artigo de Revista Científica

Publicado em /08/2010
Português

Relevância na Pesquisa
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We present the results of surveys of diversity in sets of >40 X-linked and autosomal loci in samples from natural populations of Drosophila miranda and D. pseudoobscura, together with their sequence divergence from D. affinis. Mean silent site diversity in D. miranda is approximately one-quarter of that in D. pseudoobscura; mean X-linked silent diversity is about three-quarters of that for the autosomes in both species. Estimates of the distribution of selection coefficients against heterozygous, deleterious nonsynonymous mutations from two different methods suggest a wide distribution, with coefficients of variation greater than one, and with the average segregating amino acid mutation being subject to only very weak selection. Only a small fraction of new amino acid mutations behave as effectively neutral, however. A large fraction of amino acid differences between D. pseudoobscura and D. affinis appear to have been fixed by positive natural selection, using three different methods of estimation; estimates between D. miranda and D. affinis are more equivocal. Sources of bias in the estimates, especially those arising from selection on synonymous mutations and from the choice of genes, are discussed and corrections for these applied. Overall...

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## ‣ Validation, Replication, and Sensitivity Testing of Heckman-Type Selection Models to Adjust Estimates of HIV Prevalence

Fonte: Public Library of Science
Publicador: Public Library of Science

Tipo: Artigo de Revista Científica

Publicado em 17/11/2014
Português

Relevância na Pesquisa
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A recent study using Heckman-type selection models to adjust for non-response in the Zambia 2007 Demographic and Health Survey (DHS) found a large correction in HIV prevalence for males. We aim to validate this finding, replicate the adjustment approach in other DHSs, apply the adjustment approach in an external empirical context, and assess the robustness of the technique to different adjustment approaches. We used 6 DHSs, and an HIV prevalence study from rural South Africa to validate and replicate the adjustment approach. We also developed an alternative, systematic model of selection processes and applied it to all surveys. We decomposed corrections from both approaches into rate change and age-structure change components. We are able to reproduce the adjustment approach for the 2007 Zambia DHS and derive results comparable with the original findings. We are able to replicate applying the approach in several other DHSs. The approach also yields reasonable adjustments for a survey in rural South Africa. The technique is relatively robust to how the adjustment approach is specified. The Heckman selection model is a useful tool for assessing the possibility and extent of selection bias in HIV prevalence estimates from sample surveys.

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## ‣ Are Foreign Migrants More Assimilated Than Native Ones?

Fonte: Instituto Universitário Europeu
Publicador: Instituto Universitário Europeu

Tipo: Trabalho em Andamento

Português

Relevância na Pesquisa
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The novelties of the paper are two. First the paper compares the pattern of wage assimilation of foreigners with both native immigrants and local natives in Italy, a country with large internal and international migration. This comparison demonstrates the role played by language and knowledge of social capital in the assimilation of immigrants relative to both natives and internal immigrants. Second we model new corrections of the selection bias due to return migration. In the wage equation we correct for selection bias through a duration extension of the traditional Heckman correction term and alternatively we use a hazard rate correction. The empirical test use the Italian administrative dataset on dependent employment (WHIP), to estimate a fixed effect model of the weekly wages of males aged 18-45 with controls for selection in return migration and unobserved heterogeneity. The three groups of workers start their careers at the same wage level but, as experience increases, the wage profiles of foreigners and natives, both immigrants and locals, diverge. A positive selection in the returns prevails, with both corrections, so that the foreign workers with lower wages are the most likely to stay in Italy. Also an “ethnic” skill differential emerges.

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## ‣ Wage assimilation : migrants versus natives and foreign migrants versus internal migrants

Fonte: Instituto Universitário Europeu
Publicador: Instituto Universitário Europeu

Tipo: Trabalho em Andamento
Formato: application/pdf; digital

Português

Relevância na Pesquisa
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The paper wants to understand the assimilation pattern of foreign migrants in Italy. Three novelties characterize this study. First, the research compares the wage assimilation of international migrants with both internal migrants and local natives in Italy, a country with substantial internal and international migration. This comparison, never exploited before, provides indirect evidence for the role played by language and knowledge of social capital in the assimilation of foreign migrants relative to both natives and internal migrants. Second, we inquired into the possible causes of under-assimilation by controlling for the date of entry and migrant sector concentration. Third, we model new corrections of the selection bias due to return migration. The correction for the selection bias is introduced in the wage equation through a duration extension of the traditional Heckman correction term and alternatively through a hazard rate correction. The empirical test uses the Italian administrative dataset on dependent employment (WHIP), to estimate a fixed effect model for the weekly wages of males aged 18-45 with controls for selection in return migration and unobserved heterogeneity. The three groups of workers start their careers at the same wage level. But...

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## ‣ Testing for sample selection in pseudo panels : theory and Monte Carlo

Fonte: Universidad de ICESI. Departamento de Economía
Publicador: Universidad de ICESI. Departamento de Economía

Tipo: info:eu-repo/semantics/workingPaper
Formato: 835110 bytes; application/pdf

Português

Relevância na Pesquisa
38.361343%

#Repeated Cross-section Models#Pseudo Panels#Selectivity Bias Testing#Discrete Analysis with Grouped Data#Monte Carlo Methods#Método de Monte Carlo#Análisis discreto#Prueba de selectividad diagonal#Modelos repetitivos de sección transversal#C23#C52

Sample selection bias is commonly used in economic models based on micro data. Despite the continuous generalization of panel data surveys, most countries still collect microeconomic information on the behavior of economic agents by means of repeated independent and representative cross-sections. This paper discusses a simple testing procedure for sample selection bias in pseudo panels. In the context of conditional mean independence panel data models we describe a pseudo panel model in which under convenient expansion of the original specification with a selectivity bias correction term the method allows us to use a Wald test of H0: as a test of the null hypothesis of absence of sample selection bias. We show that the proposed selection bias correction term is proportional to Inverse Mills ratio with an argument equal to the normit of a consistent estimation of the observed proportion of individuals in each cohort. This finding can be considered a cohort counterpart of Heckmans selectivity bias correction for the individual case and generalizes to some extent previous existing results in the empirical labour literature. Monte Carlo analysis shows the test does not reject the null for fixed T at a 5% significance level in finite samples and increases its power when utilizing cohort size corrections as suggested by Deaton (1985). As a side effect...

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## ‣ Building or Bypassing Recipient Country Systems : Are Donors Defying the Paris Declaration?

Fonte: World Bank, Washington, DC
Publicador: World Bank, Washington, DC

Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research

Português

Relevância na Pesquisa
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#ACCESS TO INFORMATION#ACCOUNTABILITY#ACCOUNTING#ACCOUNTING SYSTEM#AID#AID-DEPENDENT COUNTRIES#ALLOCATION#ANNUAL BUDGET#AUDITING#AUDITS#BASIC

The 2005 Paris Declaration on Aid
Effectiveness sets targets for increased use by donors of
recipient country systems for managing aid. It also calls
for donors to be more responsive to the quality of recipient
country systems: the optimal level of their use, in terms of
maximizing the development effectiveness of aid, is believed
to vary with their quality. This study investigates the
degree to which donors' use of country systems is in
fact positively related to their quality, using indicators
explicitly endorsed for this purpose by the Paris
Declaration and covering the 2005-2010 period. The results
of these tests strongly confirm a positive and significant
relationship, and show it is robust to corrections for
potential sample selection, omitted variables, or
endogeneity bias. The result holds even when estimates are
informed only by variation over time within each
donor-recipient pair in use and quality of country systems.
Moreover, donor-specific tests show that use of country
systems varies positively with their quality for the vast
majority of donors. These findings contradict several other
studies that claim there is no relation and imply that
donors in this respect are failing to live up to their
commitments under the Paris Declaration. The author's
interpretation of the available evidence on use of country
systems is more favorable: donors' behavior over the
measurement period is largely consistent with their
commitments in this area. In this respect...

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## ‣ Are There Lasting Impacts of Aid to Poor Areas? Evidence from Rural China

Fonte: World Bank, Washington, DC
Publicador: World Bank, Washington, DC

Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research

Português

Relevância na Pesquisa
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#ACCESS TO CREDIT#ACCESS TO SERVICES#ACCOUNTING#ACCURATE ESTIMATES#AGRICULTURAL DEVELOPMENT#AGRICULTURAL DEVELOPMENT BANK#AGRICULTURAL PRODUCTIVITY#AID EFFECTIVENESS#ANNUAL INCOME#ANNUAL RETURNS#ANTI-POVERTY

The paper revisits the site of a large,
World Bank-financed, rural development program in China 10
years after it began and four years after disbursements
ended. The program emphasized community participation in
multi-sectoral interventions (including farming, animal
husbandry, infrastructure and social services). Data were
collected on 2,000 households in project and nonproject
areas, spanning 10 years. A double-difference estimator of
the program's impact (on top of pre-existing
governmental programs) reveals sizeable short-term income
gains that were mostly saved. Only modest gains to mean
consumption emerged in the longer term-in rough accord with
the gain to permanent income. Certain types of households
gained more than others. The educated poor were
under-covered by the community-based selection
process-greatly reducing overall impact. The main results
are robust to corrections for various sources of selection
bias, including village targeting and interference due to
spillover effects generated by the response of local
governments to the external aid.

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## ‣ Determinants of hospital tax-exempt debt yields: corrections for selection and simultaneous equation bias.

Fonte: PubMed
Publicador: PubMed

Tipo: Artigo de Revista Científica

Publicado em /12/1992
Português

Relevância na Pesquisa
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The cost of capital for hospitals is a topic of continuing interest as Medicare's new capital payment policy is implemented. This study examines the determinants of tax-exempt revenue bond yields, the primary source of long-term capital for hospitals. Two important methodological issues are addressed. A probit analysis estimates the probability that a hospital or system will be observed in the tax-exempt market. A selection-corrected two-stage least squares analysis allows for the simultaneous determination of bond yield and bond size. The study is based on a sample of hospitals that issued tax-exempt revenue bonds in 1982-1984, the years immediately surrounding implementation of Medicare's new payment system based on diagnosis-related groups, and an equal number of hospitals not in the market during the study period. Results suggest that hospital systems and hospitals with high occupancy rates are most likely to enter the tax-exempt revenue bond market. The yield equation suggests that hospital-specific variables may not be good predictors of the cost of capital once estimates are corrected for selection.

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## ‣ Weak lensing power spectra for precision cosmology: Multiple-deflection, reduced shear and lensing bias corrections

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Português

Relevância na Pesquisa
27.84247%

It is usually assumed that the ellipticity power spectrum measured in weak
lensing observations can be expressed as an integral over the underlying matter
power spectrum. This is true at second order in the gravitational potential. We
extend the standard calculation, constructing all corrections to fourth order
in the gravitational potential. There are four types of corrections:
corrections to the lensing shear due to multiple-deflections; corrections due
to the fact that shape distortions probe the reduced shear $\gamma/(1-\kappa)$
rather than the shear itself; corrections associated with the non-linear
conversion of reduced shear to mean ellipticity; and corrections due to the
fact that observational galaxy selection and shear measurement is based on
galaxy brightnesses and sizes which have been (de)magnified by lensing. We show
how the previously considered corrections to the shear power spectrum
correspond to terms in our analysis, and highlight new terms that were not
previously identified. All correction terms are given explicitly as integrals
over the matter power spectrum, bispectrum, and trispectrum, and are
numerically evaluated for the case of sources at z=1. We find agreement with
previous works for the ${\mathcal O}(\Phi^3)$ terms. We find that for ambitious
future surveys...

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## ‣ Bias in the Estimation of Global Luminosity Functions

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 09/02/2004
Português

Relevância na Pesquisa
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We discuss a bias present in the calculation of the global luminosity
function
(LF) which occurs when analysing faint galaxy samples. This effect exists
because of the different spectral energy distributions of galaxies, which are
in turn quantified by the k-corrections. We demonstrate that this bias occurs
because not all galaxy types are visible in the same absolute magnitude range
at a given redshift and it mainly arises at high redshift since it is related
to large k-corrections. We use realistic simulations with observed LFs to
investigate the amplitude of the bias. We also compare our results to the
global LFs derived from Hubble Deep Field-North and -South (HDF) surveys. We
conclude that, as expected, there is no bias in the global LF measured in the
absolute magnitude range where all galaxy types are observable. Beyond this
range the faint-end slope of the global LF can be over/under-estimated
depending on the adopted LF estimator. The effect is larger when the reference
filter in which the global LF is measured, is far from the rest-frame filter in
which galaxies are selected. The fact that LF estimators are differently
affected by this bias implies that the bias is minimal when the different LF
estimators give measurements consistent with one another at the faint-end. For
instance...

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## ‣ Lensing Corrections to Features in the Angular Two-Point Correlation Function and Power Spectrum

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Português

Relevância na Pesquisa
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It is well known that magnification bias, the modulation of galaxy or quasar
source counts by gravitational lensing, can change the observed angular
correlation function. We investigate magnification-induced changes to the shape
of the observed correlation function w(\theta) and the angular power spectrum
C_{\ell}, paying special attention to the matter-radiation equality peak and
the baryon wiggles. Lensing mixes the correlation function of the source
galaxies with the matter correlation at the lower redshifts of the lenses.
Since the lenses probe structure nearer to the observer, the angular scale
dependence of the lensing terms is different from that of the sources, thus the
observed correlation function is distorted. We quantify how the lensing
corrections depend on the width of the selection function, the galaxy bias b,
and the number count slope s. The correction increases with redshift and larger
corrections are present for sources with steep number count slopes and/or broad
redshift distributions. The most drastic changes to C_{\ell} occur for
measurements at z >~1.5 and \ell <~ 100. For the source distributions we
consider, magnification bias can shift the matter-radiation equality scale by
1-6% at z ~ 1.5 and by z ~ 3.5 the shift can be as large as 30%. The baryon
bump in \theta^2w(\theta) is shifted by <~ 1% and the width is typically
increased by ~10%. Shifts of >~ 0.5% and broadening of >~ 20% occur only for
very broad selection functions and/or galaxies with (5s-2)/b>~2. However...

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## ‣ Bias Properties of Extragalactic Distance Indicators.XI. Methods to Correct for Observational Selection Bias for RR Lyrae Absolute Magnitudes from Trigonometric Parallaxes Expected from the FAME Astrometric Satellite

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 22/01/2002
Português

Relevância na Pesquisa
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Please note that this abstract has been shortened from that found in the
paper. A brief history is given of the development of the correction for
observation selection bias inherent in the calibration of absolute magnitudes
using trigonometric parallaxes. As a tutorial to gain an intuitive
understanding of several complicated trigonometric bias problems, we study a
toy bias model of a parallax catalog which incorporates assumed parallax
measuring errors of various severities. The two effects of bias errors on the
derived absolute magnitudes are (1) the Lutz-Kelker correction itself that
depends on the fractional parallax error and the spatial distribution, and (2)
a Malmquist-like `incompleteness' correction of opposite sign due to various
apparent magnitude cut-offs as they are progressively imposed on the catalog.
The simulations involve 3 million stars spread with varying density
distributions in a volume bounded by a radius of 50,000 pc. A fixed absolute
magnitude of M_V = +0.6 is used to imitate RR Lyrae variables in the mean. The
bias is demonstrated for various assumed spatial densities and parallax error
models, including one that is projected for the FAME satellite. The effects of
imposing magnit ude limits and limits on the `observer's' error are displayed.
We contrast the method of calculating mean absolute magnitude directly from the
parallaxes where bias corrections are mandatory...

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## ‣ Performance analysis and optimal selection of large mean-variance portfolios under estimation risk

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 16/10/2011
Português

Relevância na Pesquisa
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We study the consistency of sample mean-variance portfolios of arbitrarily
high dimension that are based on Bayesian or shrinkage estimation of the input
parameters as well as weighted sampling. In an asymptotic setting where the
number of assets remains comparable in magnitude to the sample size, we provide
a characterization of the estimation risk by providing deterministic
equivalents of the portfolio out-of-sample performance in terms of the
underlying investment scenario. The previous estimates represent a means of
quantifying the amount of risk underestimation and return overestimation of
improved portfolio constructions beyond standard ones. Well-known for the
latter, if not corrected, these deviations lead to inaccurate and overly
optimistic Sharpe-based investment decisions. Our results are based on recent
contributions in the field of random matrix theory. Along with the asymptotic
analysis, the analytical framework allows us to find bias corrections improving
on the achieved out-of-sample performance of typical portfolio constructions.
Some numerical simulations validate our theoretical findings.

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## ‣ The WiggleZ Dark Energy Survey: the selection function and z=0.6 galaxy power spectrum

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 29/03/2010
Português

Relevância na Pesquisa
27.537373%

We report one of the most accurate measurements of the three-dimensional
large-scale galaxy power spectrum achieved to date, using 56,159 redshifts of
bright emission-line galaxies at effective redshift z=0.6 from the WiggleZ Dark
Energy Survey at the Anglo-Australian Telescope. We describe in detail how we
construct the survey selection function allowing for the varying target
completeness and redshift completeness. We measure the total power with an
accuracy of approximately 5% in wavenumber bands of dk=0.01 h/Mpc. A model
power spectrum including non-linear corrections, combined with a linear galaxy
bias factor and a simple model for redshift-space distortions, provides a good
fit to our data for scales k < 0.4 h/Mpc. The large-scale shape of the power
spectrum is consistent with the best-fitting matter and baryon densities
determined by observations of the Cosmic Microwave Background radiation. By
splitting the power spectrum measurement as a function of tangential and radial
wavenumbers we delineate the characteristic imprint of peculiar velocities. We
use these to determine the growth rate of structure as a function of redshift
in the range 0.4 < z < 0.8, including a data point at z=0.78 with an accuracy
of 20%. Our growth rate measurements are a close match to the self-consistent
prediction of the LCDM model. The WiggleZ Survey data will allow a wide range
of investigations into the cosmological model...

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## ‣ A Bayesian Monte-Carlo Analysis of the M-sigma Relation

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 19/08/2012
Português

Relevância na Pesquisa
18.281434%

We present an analysis of selection biases in the M-sigma relation using
Monte- Carlo simulations including the sphere of influence resolution selection
bias and a selection bias in the velocity dispersion distribution. We find that
the sphere of influence selection bias has a significant effect on the measured
slope of the M-sigma relation, modeled as \beta_intrinsic = -4.69 +
2.22\beta_measured, where the measured slope is shallower than the model slope
in the parameter range of \beta > 4, with larger corrections for steeper model
slopes. Therefore, when the sphere of influence is used as a criterion to
exclude unreliable measurements, it also in- troduces a selection bias that
needs to be modeled to restore the intrinsic slope of the relation. We find
that the selection effect due to the velocity dispersion distribution of the
sample, which might not follow the overall distribution of the population, is
not important for slopes of \beta ~ 4-6 of a logarithmically linear M-sigma
relation, which could impact some studies that measure low (e.g., \beta < 4)
slopes. Combining the selection biases in velocity dispersions and the sphere
of influence cut, we find the uncertainty of the slope is larger than the value
without modeling these effects...

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## ‣ The WiggleZ Dark Energy Survey: the selection function and z = 0.6 galaxy power spectrum

Fonte: Royal Astronomical Society
Publicador: Royal Astronomical Society

Tipo: Article; PeerReviewed
Formato: application/pdf

Publicado em 01/08/2010
Português

Relevância na Pesquisa
27.537373%

We report one of the most accurate measurements of the three-dimensional large-scale galaxy power spectrum achieved to date, using 56 159 redshifts of bright emission-line galaxies at effective redshift z ≈ 0.6 from the WiggleZ Dark Energy Survey at the Anglo-Australian Telescope. We describe in detail how we construct the survey selection function allowing for the varying target completeness and redshift completeness. We measure the total power with an accuracy of approximately 5 per cent in wavenumber bands of Δk= 0.01 h Mpc^(−1). A model power spectrum including non-linear corrections, combined with a linear galaxy bias factor and a simple model for redshift-space distortions, provides a good fit to our data for scales k < 0.4 h Mpc^(−1). The large-scale shape of the power spectrum is consistent with the best-fitting matter and baryon densities determined by observations of the cosmic microwave background radiation. By splitting the power spectrum measurement as a function of tangential and radial wavenumbers, we delineate the characteristic imprint of peculiar velocities. We use these to determine the growth rate of structure as a function of redshift in the range 0.4 < z < 0.8, including a data point at z= 0.78 with an accuracy of 20 per cent. Our growth rate measurements are a close match to the self-consistent prediction of the Λ cold dark matter model. The WiggleZ survey data will allow a wide range of investigations into the cosmological model...

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## ‣ Weak lensing power spectra for precision cosmology : Multiple-deflection, reduced shear, and lensing bias corrections

Fonte: EDP Sciences
Publicador: EDP Sciences

Tipo: Article; PeerReviewed
Formato: application/pdf

Publicado em /11/2010
Português

Relevância na Pesquisa
27.84247%

It is usually assumed that the ellipticity power spectrum measured in weak lensing observations can be expressed as an integral over
the underlying matter power spectrum. This is true at order O(Φ^2) in the gravitational potential. We extend the standard calculation,
constructing all corrections to order O(Φ^4). There are four types of corrections: corrections to the lensing shear due to multiple-deflections;
corrections due to the fact that shape distortions probe the reduced shear γ/(1 − κ) rather than the shear itself; corrections
associated with the non-linear conversion of reduced shear to mean ellipticity; and corrections due to the fact that observational galaxy
selection and shear measurement is based on galaxy brightnesses and sizes which have been (de)magnified by lensing. We show how
the previously considered corrections to the shear power spectrum correspond to terms in our analysis, and highlight new terms that
were not previously identified. All correction terms are given explicitly as integrals over the matter power spectrum, bispectrum, and
trispectrum, and are numerically evaluated for the case of sources at z = 1. We find agreement with previous works for the O(Φ^3)
terms. We find that for ambitious future surveys...

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## ‣ O atrito nas pesquisas longitudinais: o caso da pesquisa mensal de emprego (PME/IBGE)

Fonte: Universidade de São Paulo. Faculdade de Economia, Administração e Contabilidade
Publicador: Universidade de São Paulo. Faculdade de Economia, Administração e Contabilidade

Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion;
Formato: application/pdf

Publicado em 01/03/2010
Português

Relevância na Pesquisa
48.15719%

#Pesquisa Mensal de Emprego#desgaste de painel#viés de atrito#correção para viés de seleção#Brazilian Monthly Employment Survey#panel attrition#attrition bias#bias selection corrections

This article aims to estimate the determinants of attrition/permanence of people in the panel of the Brazilian Monthly Employment Survey (PME/IBGE) and also to test the bias emerged from ignorability of attrition selection in regression analyses. Results point out a strong correlation between attrition rate and characteristics closely related to geographic mobility. In addition, both survey design aspects and socioeconomic events are significantly related to the probability of attrition. In selection correction models, we find that all selection mechanisms are endogenous, even though they are not directly correlated with the equation of interest. Finally, we show that ignoring the endogeneity of sample selection, such as attrition, may imply to a biased analysis. However, controlling for only some selection mechanism, not controlling for all, may provide estimators even more biased than no controlling.; O objetivo deste artigo é estimar os determinantes da permanência de pessoas no painel da Pesquisa Mensal de Emprego (PME) e, além disso, testar se ignorar a não-aleatoriedade do desgaste no painel causa algum viés em análises de regressão. Os resultados apontam que há uma forte correlação da taxa de atrito com as características geralmente associadas a uma mobilidade geográfica maior. Além disso...

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## ‣ Selectivity and the gender wage gap decomposition in the presence of a joint decision process

Fonte: Suntory and Toyota International Centres for Economics and Related Disciplines, London School of Economics and Political Science
Publicador: Suntory and Toyota International Centres for Economics and Related Disciplines, London School of Economics and Political Science

Tipo: Monograph; NonPeerReviewed
Formato: application/pdf

Publicado em /12/2006
Português

Relevância na Pesquisa
27.813643%

#HQ The family. Marriage. Woman#HN Social history and conditions. Social problems. Social reform#HD Industries. Land use. Labor

In this paper we revisit the gender decomposition of wages in the presence of selection bias. We show that when labor market participation decisions of couples are not independent, the sample selection corrections used in the literature have been incomplete (incorrect). We derive the appropriate sample selection corrections, based on a reduced form model for the joint participation decisions of both spouses. The influence that husbands’ participation decision has on the female participation decision also highlights the importance of using data on both spouses for the analysis of the gender wage gap. Taking account of these issues might influence the outcome of the decomposition analysis and affect the evidence of discrimination. We analyze its potential impact by analyzing the gender earnings differential using Canadian census data.

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