Adolescence and the next generation.

Adolescent growth and social development shape the early development of offspring from preconception through to the post-partum period through distinct processes in males and females. At a time of great change in the forces shaping adolescence, including the timing of parenthood, investments in today's adolescents, the largest cohort in human history, will yield great dividends for future generations.

Publisher Correction: Adolescence and the next generation.

In Fig. 4a of this Analysis, owing to an error during the production process, the year in the header of the right column was '2016' rather than '2010'. In addition, in the HTML version of the Analysis, Table 1 was formatted incorrectly. These errors have been corrected online.

The Global Adolescent Fertility Decline is Counteracted by Increasing Teen Births in Sub-Saharan Africa.

There is a lack of understanding of the persistence of elevated teen fertility rates in certain regions and countries, in contrast to the significant decline observed in other regions globally. This report considers fertility trends among 15- to 19-year olds in the period 1950-2020 and explores potential driving factors behind the significant shifts that occurred over this period. The countries where teen fertility remains high are those with fast-growing populations, primarily located in sub-Saharan Africa. Countries with higher teen fertility are typically characterized by limited use of modern contraception, lower education levels, and early marriage. Sub-Saharan Africa has emerged as the world region with the most teen births, increasing its proportion of global teen births from 12 percent in 1950 to 47 percent in 2020, a time during which this region's share of the global adolescent (15-19) population grew from 7.5 percent to 19 percent. By 2035, 67 percent of all teen births globally are projected to occur in this region. Consequently, the future number of births to teenage mothers will to a large extent depend on the development in sub-Saharan Africa over the coming decades.

Religious affiliation at time of death - Global estimates and projections.

AIMS: Religious affiliation influences societal practices regarding death and dying, including palliative care, religiously acceptable health service procedures, funeral rites and beliefs about an afterlife. We aimed to estimate and project religious affiliation at the time of death globally, as this information has been lacking. METHODS: We compiled data on demographic information and religious affiliation from more than 2500 surveys, registers and censuses covering 198 nations/territories. We present estimates of religious affiliation at the time of death as of 2010, projections up to and including 2060, taking into account trends in mortality, religious conversion, intergenerational transmission of religion, differential fertility, and gross migration flows, by age and sex. RESULTS: We find that Christianity continues to be the most common religion at death, although its share will fall from 37% to 31% of global deaths between 2010 and 2060. The share of individuals identifying as Muslim at the time of death increases from 21% to 24%. The share of religiously unaffiliated will peak at 17% in 2035 followed by a slight decline thereafter. In specific regions, such as Europe, the unaffiliated share will continue to rises from 14% to 21% throughout the period. CONCLUSIONS: Religious affiliation at the time of death is changing globally, with distinct regional patterns. This could affect spatial variation in healthcare and social customs relating to death and dying.

A Comparative Study of Segregation Patterns in Belgium, Denmark, the Netherlands and Sweden: Neighbourhood Concentration and Representation of Non-European Migrants.

In this paper, we use geo-coded, individual-level register data on four European countries to compute comparative measures of segregation that are independent of existing geographical sub-divisions. The focus is on non-European migrants, for whom aggregates of egocentric neighbourhoods (with different population counts) are used to assess small-scale, medium-scale, and large-scale segregation patterns. At the smallest scale level, corresponding to neighbourhoods with 200 persons, patterns of over- and under-representation are strikingly similar. At larger-scale levels, Belgium stands out as having relatively strong over- and under-representation. More than 55% of the Belgian population lives in large-scale neighbourhoods with moderate under- or over-representation of non-European migrants. In the other countries, the corresponding figures are between 30 and 40%. Possible explanations for the variation across countries are differences in housing policies and refugee placement policies. Sweden has the largest and Denmark the smallest non-European migrant population, in relative terms. Thus, in both migrant-dense and native-born-dense areas, Swedish neighbourhoods have a higher concentration and Denmark a lower concentration of non-European migrants than the other countries. For large-scale, migrant-dense neighbourhoods, however, levels of concentration are similar in Belgium, the Netherlands, and Sweden. Thus, to the extent that such concentrations contribute to spatial inequalities, these countries are facing similar policy challenges.

The health-adjusted dependency ratio as a new global measure of the burden of ageing: a population-based study.

BACKGROUND: The old-age dependency ratio (OADR), which is the ratio of older people (aged ≥65 years) to working age people (aged 20-64 years), is the most common way to assess and compare the burden of population ageing in different countries. However, the relationship between chronological age and dependency varies widely across countries. We therefore present the health-adjusted dependency ratio (HADR), a new measure of ageing burden based on the ageing-related health of the adult population. METHODS: In this population-based study we used health data for diseases and injuries for 2017 from the Global Burden of Disease project and population data for 2017 from the UN's Population Division to identify the number of adults (aged >20 years) in each country who have the same or higher ageing-related disease burden as the global average 65-year-old. We then calculated the HADR as the ratio of adults who were less healthy than the average 65-year-old (dependent population) to those in better health (supporting population) and compared the HADR with the OADR for 188 countries. We also used cross-sectional, bivariate regression analysis to investigate whether the HADR is a more powerful predictor of changes in per capita health-care expenditure than the OADR as a measure of predictive validity. FINDINGS: Many demographically younger populations have an earlier onset of ageing-related disease, and many demographically older populations have a later onset. For instance, Pakistan has an OADR of 0·09 and an HADR of 0·19, and France has an OADR of 0·35 and an HADR of 0·13. Relative to the OADR, the HADR suggests that Asia, western Europe, and North America have a lower ageing burden, whereas central Asia, southern Asia, and Africa have a greater burden. While Japan and countries in western Europe have the highest OADR, Russia, Papua New Guinea, and countries in southeast Europe have the highest HADR. Relative to the OADR, the HADR suggests that there is much less variation in the burden of ageing across countries than has previously been assumed. HADR was also more closely associated with growth in health spending than the OADR. A 0·1 increase in the HADR was associated with a 2·9 percentage points larger growth rate in per capita spending (p=0·0001), and a 0·1-point increase in the OADR was associated with a 1·8 percentage point larger growth rate. INTERPRETATION: The OADR probably overestimates the burden of population ageing in many demographically older countries and underestimates the ageing burden in many demographically younger countries, which implies that the challenges associated with ageing are more universal than previously thought, and that the world cannot easily be divided in a young and an old groups of nations. FUNDING: None.

Religious Affiliation Among Older Age Groups Worldwide: Estimates for 2010 and Projections Until 2050.

Objectives: The religious landscape of older adults around the world is changing profoundly. Yet until now, no study has chronicled these changes or compared expected aging patterns of religious groups. Differential aging among religious groups can have important economic and social consequences. This study estimates and projects the future religious composition by age at the global and regional levels. Method: This study presents estimates of age structures by religion for 2010 and projections until 2050. It is based on analyses of more than 2,500 censuses, registers, and surveys from 198 countries. Regional and global results are the aggregate of demographic projections carried out at the country level. Results: In 2010, Muslims were least likely to be aged 60 or older (7% of all Muslims), and Jews were most likely to be in this age group (20% of all Jews). By 2050, we project that Buddhists and the religiously unaffiliated will have the oldest populations (both will have 32% above the age of 60), whereas Muslims will remain the youngest religious group (with only 16% above the age of 60). Christians will, globally, age relatively slowly, from 14% to 21% above the age of 60 from 2010 to 2050. Discussion: The religious landscape among the world's seniors will change fundamentally in the coming years, due to the combination of rapid aging among the religiously unaffiliated and Buddhist populations and the persistence of relatively young age structures among Muslims and Christians, which are the dominant religions in Africa.