background & aim: considering the lack of information regarding the effects of religion on young couples’ fertility preferences, this study aimed to evaluate the relationship between religious beliefs and fertility preferences among engaged couples in mashhad, iran, in 2013. methods:this cross-sectional study was conducted on 450 engaged couples, referring to premarital counseling clinics at he...

in a case control study the effects of literacy, socio-economic status and the fertility behavior of mothers were fully investigated in two groups. out of 13123 babies born in 17 hospitals during almost 8 months in 1988-1989 in tehran 730 had a low birth weight (less than 2500 gr). as a control group, 1460 births were randomly selected from normal weight births. some basic findings are as follo...

background and purpose: birth outcomes and fertility measures are commonly evaluated in maternal and child health integrated program (mchip) in the field of public health. given the key role of time- trend study in the projection of current data to the future, this population-based study aimed to describe the significant changes of birth outcomes and fertility measures in the rural population o...

Fertility has declined very markedly in the majority of developing countries over the past thirty to forty years, and it continues to decline almost everywhere. As a result, fertility has reached very low levels in many countries. In addition, currently more than 40 per cent of the world’s population lives in countries with total fertility levels lower than 2.1 children per woman, the level tha...

Longer lives and fertility far below the replacement level of 2.1 births per woman are leading to rapid population aging in many countries. Many observers are concerned that aging will adversely affect public finances and standards of living. Analysis of newly available National Transfer Accounts data for 40 countries shows that fertility well above replacement would typically be most beneficia...

This paper shows how fertility is determined in a model that assumes the existence of child care services. When child care services exist, two stable multiple equilibria result: One is a stable, steady state that brings about low fertility with low labor participation; the other, a stable state that brings about high fertility with high labor participation. Moreover, this paper also analyzes th...

In this paper we conduct descriptive aggregate analyses to revisit the relation between low and lowest-low period fertility on the one, and cohort fertility and key fertilityrelated behaviors—such as leaving the parental home, marriage and female labor force participation—on the other side. First, we identify a systematic pattern of lowest-low fertility that is characterized by a rapid delay of...

World population growth has been slowing down, primarily as a result of the reduction in fertility in the majority of countries, both developed and developing. In 1970-1975 there were just 19 countries with below-replacement fertility, but by 2000-2005 there were 65. Over the same time period, the number of countries having very low fertility─that is, a total fertility lower than 1.3 children p...

The challenge hypothesis posits that male testosterone levels increase in the presence of fertile females to facilitate mating and increase further in the presence of male rivals to facilitate male-male competition. This hypothesis has been supported in a number of nonhuman animal species. We conducted an experiment to test the challenge hypothesis in men. Thirty-four men were randomly assigned...