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Current trends and issues in British fertility analysis. Jessica Chamberlain Fertility Analysis Unit, Office for National Statistics Thanks to Steve Smallwood, John Jeffs and Baljit Gill. Overview. 1) Current trends in fertility Background Analysis of increases - Age
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Current trends and issues in British fertility analysis Jessica Chamberlain Fertility Analysis Unit, Office for National Statistics Thanks to Steve Smallwood, John Jeffs and Baljit Gill
Overview 1) Current trends in fertility Background Analysis of increases - Age - Geography - Registration type - Country of birth - Parity 2) Current issues in fertility Fertility and migration Subnational fertility
Trends in the TFR Total fertility rate, England and Wales 1938-2004 Children per woman 3.5 1960s baby boom 3 Post World War Two baby boom 2.5 Recent 2 rise in fertility 1930s low 1.5 Late 1970s low fertility fertility 1 0.5 0 1938 1943 1948 1953 1958 1963 1968 1973 1978 1983 1988 1993 1998 2003
Trends in childbearing behaviour • Decline in completed family size. Decrease from 2.46 children for 1934 cohort to 1.99 for most recent cohort to complete childbearing. • Increase in proportion of women remaining childless. Increase from 9 per cent of women born in 1945 to around 20 per cent for women soon to complete childbearing. • Increased mean age at first birth • Childbearing to women in their 20s has decreased and increased to women in their 30s.
Recent increase in fertility Record low TFR of 1.63 in 2001. Increase every year since then. The rise from 2002 to 2003 was the largest absolute and proportional change in TFR since 1979.
Has this increase occurred all over England and Wales? • This rise has occurred all over England and Wales to varying degrees. • In 2003 all GORs except the North East saw rises of 4.3 to 4.8 per cent in their TFR from 2002. In 2004 the TFR increased by 3 or more per cent everywhere except the South East.
Registration type • Percentage increase in births jointly registered both at same address and at different addresses was greater than the overall percentage increase in births. • Percentage increase in births registered by the mother alone was below the overall percentage increase in the number of births.
Country of birth of parents • Since 1995 the proportion of births occurring to mother’s born outside the UK has been rising. • This rise became steeper between 1999 to 2004. • In 2004 19.5 per cent of all births were to women born outside of the UK.
Parity • Increases in probability of progression to first birth, particularly for older women in last two years. • So the number of women who would remain childless has decreased from one in four women to one in five. • Probability of having a second birth has not increased back to previous levels, but the number of women exposed to having a second birth has increased. • Some of low fertility from 1995 onwards appears to be associated with a decline in women in their 30s progressing to have a second birth.
Is this rise the start of a new trend? • Fertility can vary year to year due in part to change in timing of births. • There were substantial rises in fertility in 1978 and 1979 after a period of record low fertility had occurred, however fertility fell again in the early 1980s. • 2000 to 2002 were years of particularly low fertility, so may be some short term catching up of births. • The rise in births to women in their 30s may indicate the continued long term trend of postponement of births to older ages. • May, in part, be an effect of the timing of births of migrants.
Future Projects • Two future projects that the Fertility Analysis Unit at ONS are undertaking to further understanding of fertility within England and Wales: 1) Relationship between migration and fertility 2) Calculating and analysing subnational fertility
Gross female international migration Source: MN, Table 2.9
1) Fertility and migration • Disruption hypothesis • When standardised for age women have lower fertility before migration than women in the destination country. • Then migrants show a rise and peak in fertility after migration. • After period of time fertility of immigrants declines and may become similar to the fertility of native born women. • Migration and family building in many cases are interrelated processes.
Fertility of immigrant women by age at entry into France, 1991-1998 Source: Toulemon (2004)
Literature • This relationship has been shown in studies in America, Canada, France, Sweden and Norway. • Age at entry and country of origin affect fertility pattern before and after migration • Different types of migration to consider: economic migration and migration to join family. Also refugees and asylum seekers likely to have a different pattern. • Toulemon (France) - Need to calculate the TFR for overseas born women taking into account age at entry and duration of stay so as not to overestimate fertility.
Using the General Household Survey (GHS) for England and Wales • GHS contains: age, country of birth, year of entry to UK and fertility history for 1971-1996, 1998 and 2000-2004 surveys. • Numbers available in GHS large enough - 615 women born outside of the UK in 2002 GHS. • May need to combine several year’s of GHS data. • Also have fertility intentions data. • Other possible data sources? BHPS?
2) Subnational fertility - Issues • Method of standardisation • Confidence intervals on fertility rates • Confidence intervals on population, from census • Other geographies, e.g. rural/urban, primary care organisations • Time trends and changing boundaries • Correlations with other factors e.g. level of deprivation, employment of women
Highest and lowest LA Total Fertility Rates, England and Wales 2003 Source: http://www.nchod.nhs.uk - TFRs with confidence intervals for 2003 for LAs, PCOs and other geographies.
