We introduce a new formal model in which demographic behavior such as fertility is postponed by differing amounts depending only on cohort membership. The cohort-based model shows the effects of cohort shifts on period fertility measures and provides an accompanying tempo adjustment to determine the period fertility that would have occurred without postponement. Cohort-based postponement spans multiple periods and produces "fertility momentum," with implications for future fertility rates. We illustrate several methods for model estimation and apply the model to fertility in several countries. We also compare the fit of period-based and cohort-based shift models to the recent Dutch fertility surface, showing how cohort- and period-based postponement can occur simultaneously.
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http://dx.doi.org/10.1007/s13524-014-0332-7 | DOI Listing |
Braz J Microbiol
January 2025
Department of Agriculture, Postgraduate Program in Agroecology, Federal University of Paraiba, Bananeiras, PB, Brazil.
The influence of arbuscular mycorrhizal fungi (AMF) inoculation on the growth and physiology of Phaseolus vulgaris L. and Zea mays L. in the Brazilian tropical seasonal dry forest is not well known.
View Article and Find Full Text PDFJ Gerontol B Psychol Sci Soc Sci
January 2025
College of Health Solutions, Arizona State University, Phoenix, AZ, USA.
Objectives: A growing body of research has identified associations between family size and cognition in older adults. These studies largely focus on older adults' own fertility history instead of sibship size, defined as one's number of siblings. Sibship size may impact cognitive development during early childhood, creating differences that may persist into late-life.
View Article and Find Full Text PDFPharmacogenet Genomics
January 2025
Reproductive Medicine, Instituto Bernabeu of Fertility and Gynaecology.
The research question is as follows: Are estrogen and progesterone receptor genotypes associated with thin endometrium? We performed a prospective cohort study of 129 patients who underwent preimplantation genetic testing for aneuploidies. These patients were categorized according to endometrial thickness: >7 mm control group (n = 94) and ≤7 mm study group (n = 35). Polymorphisms in the genes ESR1 (rs9340799 and rs3138774), ESR2 (rs1256049 and rs4986938), and PGR (rs1042838) were analyzed.
View Article and Find Full Text PDFPaediatr Perinat Epidemiol
January 2025
Department of Epidemiology, Boston University School of Public Health, Boston, Massachusetts, USA.
Background: Epidemiologic studies have demonstrated that ambient concentrations of particulate matter < 2.5 μm (PM) are associated with reduced fecundability, the per cycle probability of conception. The specific constituents driving this association are unknown.
View Article and Find Full Text PDFCancer Causes Control
January 2025
University of Arizona Cancer Center, University of Arizona, Tucson, CA, USA.
Purpose: There is a consistent relationship with greater ovulation frequency and increased risk of ovarian cancer. However, prior research on infertility, which may be associated with ovulation frequency through multiple mechanisms, and ovarian cancer has yielded conflicting results, possibly due to prior research conflating fertility treatment with infertility and restricting follow-up to premenopausal cases. Our objective was to determine the association between infertility and risk of postmenopausal ovarian cancer, overall and by histotype, in a population that had not received treatment with IVF.
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