Double logistic curve in regression modeling

The logistic sigmoid curve is widely used in nonlinear regression and in binary response modeling. There are problems corresponding to a double sigmoid behavior which consists of the first increase to an early saturation at an intermediate level, and the second sigmoid with the eventual plateau of saturation. A double sigmoid behavior is usually achieved using additive or multiplicative combinations of logit and more complicated functions with numerous parameters. In this work, double sigmoid functions are constructed as logistic ones with a sign defining the point of inflection and with an additional powering parameter. The elaborated models describe rather complicated double saturation behavior via only four or five parameters which can be efficiently estimated by nonlinear optimization techniques. Theoretical features and practical applications of the models are discussed.     

Counting Young Carers in Switzerland – A Study of Prevalence

An online survey of children in school grades 4–9 (mostly aged 10–15) was conducted in order to determine the prevalence of young carers in Switzerland using a 2‐stage stratified sampling approach. 4082 respondents were drawn from 230 schools. A total of 3991 respondents were included in the analysis and of these 307 (7.7%) were identified as young carers. The population estimate of prevalence was 7.9 per cent. This suggests that there are around 38 400 young carers in school grades 4–9 in Switzerland. Extrapolating to the 9–16 age group gives a figure of almost 51 500.     

Field work with the computer: Criteria for assessing systems

Computers, both large and small, can be of great assistance to a field worker. This assistance falls mainly in the area of relieving the field worker from tedious mechanical phases such as typing, sorting, and retrieving information. An examination of field work methods identifies issues and problems which must be addressed by any system for undertaking field work. A rationale for a loose and inclusive (as opposed to an exhaustive and mutually exclusive) coding system is presented. Efficiency, confidentiality, data reduction, and flexibility of testing propositions are discussed as criteria for assessing any system which facilitates field work. The paper concludes by contrasting the methods previously used to collect data, reduce its bulk, code, and retrieve information with what is possible with today's computer hardware and software, and with what will be possible in the near future.We wish to thank Peter Conrad, Susan LeBailly, and the anonymous reviewer of this article for their comments and suggestions.     

Neo-natal mortality in South Asia: The special role of tetanus

First-year mortality in rural Uttar Pradesh is characterized by a predominance (60 per cent) of deaths during the first month of life, of which 66 per cent are reported to be due to tetanus. This pattern is not typical of the historical experience of many developed countries and the current experience of some less developed countries where post-neo-natal mortality predominates. To examine this phenomenon, two causal models of neo-natal mortality (one for tetanus and one for all other diseases) are developed and tested using retrospective survey data from 2000 couples living in rural Uttar Pradesh.

Neo-natal tetanus mortality is found to be primarily a function of opportunities for exposure to the disease (e.g. lack of antiseptic birth practices, ownership of large animals) rather than of socio-economic status or demographic variables. The importance of examining neo-natal mortality by cause, and the shortcomings inherent in making inferences from the historical experiences of Western nations are emphasized.     

Forced Marriage and Birth Outcomes

We study the impact of marriages resulting from bride kidnapping on infant birth weight. Bride kidnapping—a form of forced marriage—implies that women are abducted by men and have little choice other than to marry their kidnappers. Given this lack of choice over the spouse, we expect adverse consequences for women in such marriages. Remarkable survey data from the Central Asian nation of Kyrgyzstan enable exploration of differential birth outcomes for women in kidnap-based and other types of marriage using both OLS and IV estimation. We find that children born to mothers in kidnap-based marriages have lower birth weight compared with children born to other mothers. The largest difference is between kidnap-based and arranged marriages: the magnitude of the birth weight loss is in the range of 2 % to 6 % of average birth weight. Our finding is one of the first statistically sound estimates of the impact of forced marriage and implies not only adverse consequences for the women involved but potentially also for their children.     

The Siting of Radioactive Waste Faculties: What Are the Effects on Communities?1

Abstract Despite literally dozens of attempts, and the expenditure of billions of dollars, efforts to site radioactive waste disposal facilities in this country have been uniformly unsuccessful. While both researchers and policymakers continue to address reasons for these failures, little attention is being given to the consequences for the communities themselves of these intensive siting battles. Using a research framework that addresses both the sources and consequences of community conflict, we examine what is happening in four different areas currently being considered as potential hosts for either a high- or a low-level radioactive waste facility. Some degree of conflict is observed in each community, although it varies from one area to another based on such differences as potential to experience economic benefits, perceptions of class and ethnic equity, and the role of extra-local players in the controversy. We conclude that current policies lead to inequitable distributions of risk that, in turn, create “fairness” questions that are important both in explaining current patterns of conflict and in anticipating long-term consequences for the affected communities.