Search results for "Sample selection"
showing 10 items of 14 documents
The public–private sector wage gap in Latvia
2018
This study investigates the public-private sector wage gap in Latvia using microdata from the labour force survey. The severity of public sector wage cuts employed as a response to the economic crisis and subsequent recovery provides a test bed to analyse whether and how the public-private sector wage gap has adjusted after consolidation-driven wage cuts. Findings reveal that the observed wage gap is slightly in favour of the public sector; however, once differences in individual characteristics and selection effects are considered, results point to a private sector wage premium. Findings also suggest that the private sector wage premium has increased since the pre-crisis period. A signific…
Evaluation of the effect of an intervention on the nutritional status of hospitalized patients
2017
Abstract Background and objectives To compare the nutritional status of a population of hospitalized patients, divided into 2 different groups, both at admission and hospital discharge, and to assess the influence of nutritional alteration during the hospital stay. Material and methods Quasi-experimental study comprising 2 groups of patients (N = 581): an intervention group (n = 303), in which nurses received specific training on managing care methodology, and a control group (n = 278), in which nurses continued their usual dynamics. Each group was made up of 2 care units with patients from both surgical and medical specialties. Inclusion criteria: patients admitted to the selected units wi…
Long term effect of teenage birth on earnings: Evidence from a British cohort study
2016
We use data from the 1970 British Cohort Study and evaluate the effect of teenage motherhood on hourly earnings at age 30, 34, 38, and 42 using alternative non-experimental estimation methods including linear regression, matching methods, and Heckman sample selection models. We conclude that teenage motherhood has a significant negative long-term effect on hourly wages. At age 42, teenage mothers earn 12% less than other women and 29% less than women who have not had any children. When compared to non-teenage mothers, the pay penalty reduces over time and becomes insignificant on the long term.
Estimation de la relation de salaires de Mincer : choix de specification et enjeux économétriques
2012
In the present doctoral thesis, we estimated Mincer’s (1974) semi logarithmic wage function for the French and Pakistani labour force data. This model is considered as a standard tool in order to estimate the relationship between earnings/wages and different contributory factors. Despite of its vide and extensive use, simple estimation of the Mincerian model is biased because of different econometric problems. The main sources of bias noted in the literature are endogeneity of schooling, measurement error, and sample selectivity. We have tackled the endogeneity and measurement error biases via instrumental variables two stage least squares approach for which we have proposed two new instrum…
On the distribution of education and democracy
2006
This paper empirically analyzes the influence of the distribution of education on democracy by controlling for unobservable heterogeneity and by taking into account the persistency of some of the variables. The most novel finding is that increase in the education attained by the majority of the population is what matters for the implementation and sustainability of democracy, rather than the average years of schooling. We show this result is robust to issues pertaining omitted variables, outliers, sample selection, or a narrow definition of the variables used to measure democracy.
Reply to Douka et al: Critical evaluation of the Ksâr 'Akil chronologies
2015
Our paper (1) proposes a new chronology for Ksâr 'Akil based on 16 accelerator mass spectrometry (AMS) determinations on shells. To minimize the possibility of dating diagenetically compromised samples, we conducted amino acid racemization analyses on the intracrystalline proteins, oxygen isotope analysis, and geochemical characterization of all dated shells. Our calibrated radiocarbon ages fit well with existing Levantine chronologies, but are up to 4,000 y older than Douka et al.’s (2). Our paper explores several possibilities for this difference, whereas Douka et al. (3) provide alternative explanations. They accept our radiocarbon ages as correct but question our sample selection and Ba…
A genetic algorithm approach to purify the classifier training labels for the analysis of remote sensing imagery
2017
This paper proposes a Genetic Algorithm (GA) approach to clean a given classifier training set for remote sensing image analysis. Starting from an initial set of training data, the new method called GA-Training Label Purifying (GA-TLP) consists of the significant training sample selection using GAs in order to maximize the classifier accuracy. This means to retain the most informative samples and to remove the uncertain, redundant, and misclassified ones. As a result of the selection process, we can obtain a purified training set. The proposed model is implemented and evaluated using a LANDSAT 7 ETM+ image. The experimental results confirm the effectiveness of the proposed approach.
The continuous sample of working lives: Improving its representativeness
2017
This paper studies the representativeness of the Continuous Sample of Working Lives (CSWL), a set of anonymized microdata containing information on individuals from Spanish Social Security records. We examine several CSWL waves (2005–2013) and show that it is not representative for the population with a pension income. We then develop a methodology to draw a large dataset from the CSWL that is much more representative of the retired population in terms of pension type, gender and age. This procedure also makes it possible for users to choose between goodness of fit and subsample size. In order to illustrate the practical significance of our methodology, the paper also contains an applicatio…
Hospital readmission rates: signal of failure or success?
2013
AbstractHospital readmission rates are increasingly used as signals of hospital performance and a basis for hospital reimbursement. However, their interpretation may be complicated by differential patient survival rates. If patient characteristics are not perfectly observable and hospitals differ in their mortality rates, then hospitals with low mortality rates are likely to have a larger share of un-observably sicker patients at risk of a readmission. Their performance on readmissions will then be underestimated. We examine hospitals’ performance relaxing the assumption of independence between mortality and readmissions implicitly adopted in many empirical applications. We use data from th…
Estimating regional differences in returns to education when schooling and location are determined endogenously
2010
While the growing supply of university skills is known to have agglomerated towards the large centers in Finland, there is no research knowledge available on the development of regional demands. This paper attempts to fill this gap by analyzing regional variation in the private-sector return to university education in Finland for the period 1970 - 2004. In the analysis, we focus on studying 1) whether there are differences in the return to university between different region types, and 2) to what extent can these differences - if they exist - be explained by differences in regional skill supply and unemployment. For the econometric analysis, we use a large register-based dataset constructed…