Browsing by Author "R.C. Yadava"

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A study on the fertility of migrants
(1981) S.N. Singh; R.C. Yadava; K.N.S. Yadava
This study explores the impact of temporary separation due to the migration of males leaving their wives at home, on fertility through a theoretical model proposed under reasonable assumptions. The application of this model to an observed set of data relating to migrants from a rural area indicates that although the fertility of such separated couples is slightly lower than the couples living together, their fecundability is quite high (0.18) in comparison to the fecundability (0.05) of the couples living together.
An adjustment of a selection bias in postpartum amenorrhea from follow-up studies
(1979) S.N. Singh; B.N. Bhattacharya; R.C. Yadava
In a prospective study in which females giving birth in a specified small interval of time are followed to obtain the distribution of the duration of postpartum amenorrhea (PPA), the observed distribution involves a selection bias because of an overrepresentation of smaller PPA. In this article, the nature of this selection bias is investigated and an analytical procedure is outlined to adjust the observed distribution of PPA in order to obtain the true distribution. The proposed technique is illustrated with one set of observed data. © 1979, Taylor & Francis Group, LLC.
An indirect technique for estimations of infant and child mortality: Data analysis from India and Bangladesh
(2003) R.C. Yadava; A.K. Tiwari
The analysis of mortality data is of vital interest to policy planners and health administrators in the formulation of development strategies to meet the health needs and demands of people and also in the implementation and evaluation of public health programmes. The study of child mortality provides useful information on the current demographic situation in that region and indicates on the prospects of potential change in future. Death is a vital event recorded through the system of civil registration. But in developing countries, quality of registered data is not very much reliable because of its failure to reach to all groups of the population affected by illiteracy and ignorance. Because of many unreliable estimates arising out of the civil registration system, exploration of indirect techniques for estimating vital indicators has become a necessity. In the present study, we have utilized an indirect technique for estimating infant mortality and under-five mortality rates by using the data of mean number of children ever born and living to currently married women aged 15-49 years. The method is essentially based on the technique of regression line analysis taking infant mortality rate or under five-mortality rate as a dependent variable and the proportion of dead children among the total children born to currently married females (15-49 years) as independent variable. The regression line analysis was computed and tested using data from National Family Health Survey (India) and Demographic and Health Survey (Bangladesh). The observed and expected rates computed from regression line were found overlapping in most cases showing complete adequacy of the proposed indirect method.
Estimation of parity progression ratios from the truncated distribution of closed and open birth intervals
(1992) R.C. Yadava; A. Pandey; N.C. Saxena
A procedure to estimate parity progression ratios in a population from the truncated distribution of open and closed birth intervals is presented. The approach is quite simple in computation and data needs. It does not require any separate data on age at last birth to the women of completed fertility as in earlier methods. The procedure is illustrated with an observed set of data. © 1992.
Impact of Heterogeneity on Closed and Open Birth Intervals
(Springer, 2019) Anup Kumar; R.C. Yadava
Vast literature is available where modelling for duration between ith and (i + 1)th births has been done. Apart from other considerations these models assume that consecutive birth intervals are independently distributed. This assumption may be quite reasonable if the population of females is homogeneous with respect to fertility parameters involved in the model. However, if population is heterogeneous with respect to these parameters, then the consecutive intervals are likely to be dependent. The behaviour of closed and open birth intervals under the condition of heterogeneity in the population with respect to certain fertility parameters is investigated. © 2018, Indian Statistical Institute.
Maximum likelihood estimates of parameters of a model for open birth interval
(1982) R.C. Yadava; M. Bhattacharya
[No abstract available]
On a probability model for closed birth interval
(1979) S.N. Singh; R.C. Yadava; A. Pandey
A probability model for the distribution of r order closed birth interval to a female with at least r births and a given marital duration has been derived under certain assumptions. The model so derived will be useful for real situations as it is free from truncation bias and relates to recent data. The model is applied to an observed distribution and it describes the data satisfactorily.
On the distribution of the menstruating interval
(2009) R.C. Yadava; Richa Pandey; A.K. Tiwari
This article is concerned with the development of some stochastic models belter suited to describe the observed distributions of the menstruating interval relating to last closed-birth interval of two types of females. In this context, two models suited for couples using or not using contraception have been proposed. In the first case, the model assumes a constant conception rale (analogous to the constant hazard rate in the life-testing problem) over lime whereas the second case assumes a time-dependent form of the conception rate. The models have been applied to the data collected in a survey conducted in Lucknow, and estimates of conception rate for the two types of females have also been obtained. Copyright © Society for the Study of Social Biology.
Sex ratio at birth: A model based approach
(2013) R.C. Yadava; Anup Kumar; U. Srivastava
There are many biological and social determinants of the sex ratio (the ratio of the number of males to the total number of children) at birth (SRB). Among these, sex selective abortion is considered the most effective. This paper attempts to examine the impact of the practice of sex selective abortion on the SRB under different hypothetical situations. This paper also investigates the effect of the desire of a sex combination of children on the SRB under different stopping rules for heterogeneity in the population regarding the probability of producing a male child (p). The results presented here are intended to further clarify the impact of some possible stopping rules on the SRB. © 2012 Elsevier B.V.
The distribution of consecutive closed birth intervals in females in Uttar Pradesh
(2007) R.C. Yadava; S.S. Sharma
Most studies of closed birth intervals are regarding their variation at specific orders among females. This paper attempts to study the nature of the distributions of consecutive closed birth intervals. Data from the Uttar Pradesh National Family Health Survey 1998-99 (NFHS-2) were analysed. It was found that, under certain assumptions, the postpartum amenorrhoea period and menstruating interval are negatively associated, indicating that socio-cultural factors are affecting the menstruating interval. © 2006 Cambridge University Press.