Особенности работы с данными, характеризующими здоровье населения: заполнение пропусков в данных
The paper describes a recent study aimed at investigating the most efficient data imputation algorithm for several methods of data analysis such as regression modeling, factor analysis, descriptive statistics, and correlation analysis. The lack of recommendations when choosing the data imputation algorithm poses the problem of choice ambiguity in each situation.
The authors consider that the data imputation algorithm should be selected according to the method employed after data improvement. In other words, it is believed that for each data analysis method the efficiency of the same data imputation algorithm is different. The statistical experiment was used to evaluate the efficiency of several data imputation algorithms for each method of data analysis.
The core idea of statistical experiment was to compare the results of each method application used in the etalon data set (without missing values) with the results obtained on a large number of artificial subsamples generated from the original data set where missing values were filed with comparable data imputation algorithms.
Generation of subsamples was carried out via the bootstrap procedure, which allowed to undertake
statistical evaluation and to build confidence intervals for each parameter before and after the data imputation.
Through this experiment the authors managed to evaluate the efficiency of such data imputation algorithms as imputation with the average trend measures, the EM algorithm, the imputation via regression model and Hot Deck algorithm for the mentioned methods of data analysis.
This article is the foreword to «Pure Theory of Law» by Hans Kelsen reedited in 2008. The author of this article, M. Jestaedt, mentions the most common mistakes and misunderstandings suffered by the legal theory of Kelsen. Jestaedt also stresses ambiguity in reception of Kelsenian ideas. He describes the context of creation and publication of «Pure Theory of Law», and accentuates the revolutionary character of this book for its époque. Jestaedt underlines the role the adherents and neophytes of Hans Kelsen played in development of his legal doctrine. Among the most important ideas of this doctrine Jestaedt cites those about self-referential character of law and about purity. Kelsen requires such purity from the methodology of legal studies and not from law which is the object of these studies.
This paper models household demand for childcare and mothers' labour force participation in Romania. The model estimates the effects of the price of childcare, mothers' wages, and household characteristics on household behaviour with respect to childcare and maternal employment. We find that both the maternal decision to become employed and the decision to use out-of-home care are sensitive to the price of childcare. A decrease in the price of care can increase the number of working mothers and thus can reduce poverty in some households. We also find that the potential market wage of the mother has a significant positive effect on the decision to purchase market care and on the decision to engage in paid employment. The level of household non-wage income has little effect on maternal employment and on the demand for childcare.
The availability and cost of child care play an important role in the decisions that households make about allocating labor and choosing between informal home care and ECD.A mother’s decision to join the labor force is based on her expected earnings compared with the costs of available day care. Insufficient child care options could be a barrier for women with children to join the labor force (for example, Kimmel 1998). The custodial role of ECD centers frees female household members for other activities and allows mothers to enter the labor market. The additional income newly employed mothers bring home can be significant and may lift some households out of poverty. In the longer term, the increased work experience may also lead to increased job skills and higher earnings for household members. Better employment options, in turn, may decrease the reliance of low-income families on government subsidies and increase their self-sufficiency.Research in developing countries also indicates that females other than the mother, especially young daughters, provide free child care, releasing mothers for paid work (for example, Deutsch 1998). For example, Psacharopoulos and Arriagada (1989) find that in Brazilian households, the presence of younger siblings has a negative effect on school attendance of older children. In El Salvador, girls missed more school than boys because they stayed home to help with chores (Bittencourt and DiCicco 1979). Deolalikar (1998) finds significant differences in girls’ (but not boys’) school enrollment in householdswith children under 3 in Kenya. He reports a particularly strong effect for girls attending secondary school. The presence of a child 3 or younger reduces the probability that a girl aged 14–17 would be enrolled in secondary school by 41 percent, conditional on other determinants of enrollment. The corresponding effect for boys is only 5 percent. These studies indicate that when child care centers are unavailable or too costly, older siblings are more likely to provide child care.
The paper studies a problem of optimal insurer’s choice of a risk-sharing policy in a dynamic risk model, so-called Cramer-Lundberg process, over infinite time interval. Additional constraints are imposed on residual risks of insureds: on mean value or with probability one. An optimal control problem of minimizing a functional of the form of variation coefficient is solved. We show that: in the first case the optimum is achieved at stop loss insurance policies, in the second case the optimal insurance is a combination of stop loss and deductible policies. It is proved that the obtained results can be easily applied to problems with other optimization criteria: maximization of long-run utility and minimization of probability of a deviation from mean trajectory.