Age-specific fertility rates are calculated by taking the total number of women-years and the length of each menstrual period. For five-year periods, this period is sixty months and for four-year periods, it is 48 months. The four-year period is used where birth displacement is believed to be important.
Age-specific fertility rate
The age-specific fertility rate is the number of live births per 1,000 women in a certain age cohort in a given year. This measure is important because it indicates fertility rates for specific age cohorts. It is also useful for analyzing the life cycle patterns of fertility. This measure is a more accurate measurement of women’s reproductive ability than the total fertility rate.
Age-specific fertility rates are calculated for women in five-year age cohorts. The numbers shown are for women aged 15 to 49. The number of teenage pregnancies decreased from a peak of 28 births per thousand women in 2007 to only 11 births per 1,000 women in 2019. The rate of fertility has also increased for women in their 30s to 34 age cohort.
Adjusting for timing effect
One important method for assessing the timing effect in fertility rates is to adjust for the age at which a woman gives birth. In the US, data on fertility from 29 cohorts are available from 1917 to 1980. Each cohort had an average age of fourteen at the start of the series, and by 1980, the average age of childbearing was 49. This means that women who had children later on in their lives had lower fertility than those who gave birth earlier.
Temporary effect (TE) is a complication in fertility measures due to the changing timing of births over a woman’s lifetime. The tempo effect is caused by changes in mean age of childbearing and birth intervals, two factors that have implications for policy decisions. For Bangladesh, for example, the tempo-adjusted TFR would be half a child higher than the BDHS estimates.
Reductions in population growth
Reductions in the world’s fertility rate are expected to lead to fewer children and slower population growth in the coming decades. In fact, by 2070, the global fertility rate is projected to fall to less than 1.9 births per woman. That’s below the replacement fertility rate of 2.1 births per woman needed to maintain the size of the population.
Reductions in the fertility rate can be attributed to a number of factors, including the empowerment of women, decreased child mortality, and increased cost of raising children. Low fertility rates also contribute to an aging population, which puts pressure on the global healthcare system. In 1952, the average global family had five children; today, that number has dropped to three.
Correlation with level of economic development
The correlation between fertility rate and level of economic development has long been an issue in economics. In the last decade, more studies have pointed to this correlation. Nevertheless, the relationship between fertility and economic development is not as clear-cut as it once was. In some countries, for example, the relationship is positive while in others it is negative. In addition, it is important to note that some regions have higher fertility rates than others.
The level of economic development is a factor that influences both fertility rate and life expectancy. The more prosperous a country is, the longer its citizens live. Similarly, the higher the GDP per capita, the more the life expectancy.