Volume 54, Part 2, 2000

Author An obituary by John Cleland
William Brass 1921-1999

William Brass, who died on 11 November 1999, is admired throughout the world of population science as one of its most creative and influential exponents. To mark his death, we publish an obituary written by John Cleland for a British newspaper, The Independent, and an appreciation by Basia Zaba. As a tribute to him, a number of William Brass's former students and colleagues have contributed to a volume of essays and reports of studies in the field of medical demography. Entitled Brass Tacks, the book has been edited by Basia Zaba and John Blacker and has a foreword by Griffith Feeney. It will be published later this year in London by The Athlone Press.
pp. 129-131

Authors David S Reher and Alberto Sanz-Gimeno
Mortality and economic development over the course of modernisation: An analysis of short-run fluctuations in Spain, 1850-1990

Distributed lag models are used to explore the issue of the importance of economic factors for demographic performance over the course of the demographic and economic modernisation of Spain.

Mortality indicators are generated by age, sex, and cause and are assessed in terms of shifts in gross domestic product. During the pre-transitional period, links between mortality and economic performance were simultaneous and rather weak but in the expected direction, declining to near the beginning of the twentieth century.

Afterwards the importance of economic shifts for mortality fluctuations increased dramatically and delayed effects began to predominate, only disappearing after 1950. The paper explains the increase in the importance of economic factors and the change in the lag structure in terms of the greater economic volatility of the 1915-1950 period, the progressive implantation of more efficient public health systems and their sensitivity to economic fluctuations, and improving levels of nutrition and general health.      
pp. 135-152

Authors Vwijo Notkola, Ian M Timaeus and Harri Siiskonen
Mortality transition in the Ovamboland region of Namibia, 1930-1990

Few long-term statistical series exist than can document the mortality transition in Africa. This paper uses data from the parish registers of the Evangelical Lutheran Church in Namibia to study mortality in Ovamboland between 1930 and 1990. The paper identifies significant discontinuities and reversals in the trend in mortality. Much of the mortality transition occurred in a rapid breakthrough concentrated between the early 1950s and early 1960s.

Adult mortality fell more than existing model life tables would predict and the pattern of relatively high early-age mortality typical of modern Africa emerged only at this time. While a range of developments in Ovamboland contributed to the overall decline in mortality, the most important factor was the establishment, by the Finnish Mission, of a Western system of health care.

In Ovamboland, the drive to 'good health at low cost' was articulated not through political institutions but through the church.
pp. 153-167

Author Gabriele Doblhammer
Reproductive history and mortality later in life: a comparative study of England and Wales and Austria

Does a woman's reproductive history influence her life span? This study explores the question with data from the contemporary populations of England and Wales and Austria.

It is the first comparative study to investigate the relationship between fertility and mortality late in life. We find similar patterns and age-specific trends of excess mortality in both populations: parity significantly influences longevity, as do both an early and a late birth.

These differences in longevity are not explained by differences in educational or family status. The impact of a woman's reproductive history on her life span is small, however, compared to the influence of her level of education or family status.
pp. 169-176

Authors Andrew Hinde and Akim J Mturi
Recent trends in Tanzanian fertility

This paper provides an assessment of the nature and magnitude of Tanzania's recent fertility decline, using robust methods for the identification of fertility trends. A decline in Tanzanian fertility began some time in the late 1970s or early 1980s. The pattern of decline exhibits similarities to patterns identified some years ago in Zimbabwe and Kenya.

The decline has been especially marked in urban areas.  It has been accompanied by a rapid rise in the contraceptive prevalence from the very low levels before 1990 to just under 20 per cent of currently married women of reproductive age. Although falling marital fertility associated with a rise in contraceptive use is the main contributor to the decline in fertility, a rise in the average age at marriage has also made a (smaller) contribution, as has the AIDS epidemic.

The fact that fertility is declining in Tanzania raises questions about the social and economic requirements for fertility transitions to begin in sub-Saharan Africa.
pp. 177-191

Author Emily Grundy
Co-residence of mid-life children with their elderly parents in England and Wales: Changes between 1981 and 1991

It its known that there have been large declines in the proportion of elderly people living in intergenerational households. Much less is known about trends in the proportion of adult children living with elderly parents.

Here I show a large decline between 1981 and 1991 in the proportion of mid-life adults living with an elderly parent or parent-in-law in England and Wales. Declines in co-residence were higher among more advantaged groups so that the characteristics of intergenerational households were less favourable in 1991 than in 1981.

Analysis of another data set, including information on the survival of parents, showed that associations between co-variates and co-residence are similar in models applied to all mid-life adults and only to those with a living parent. These changes suggest a continuing trend towards residential independence as a preferred option, with those unable to attain or maintain this coming to represent a more disadvantaged group.
pp. 193-206

Authors Philip Rees, Martin Bell, Oliver Duke-Williams and Marcus Blake
Problems and solutions in the measurement of migration intensities: Australia and Britain compared.

The differences in internal mobility between national populations are large and complex in origin. In studying them we must use comparable indicators. This paper discusses how measures of migration intensity at the national level should be constructed, drawing on analyses of residential mobility in Australia and Britain.

We argue for the tailoring of intensity measures to observation plan and to age-time plan, and for removing the effects of mortality and external migration on census-based measures. We propose simple estimation of infant migrants, a standard stopping-age in calculating gross measures of migration, and argue for the use of a common population for computing migration expectancies.

We conclude with recommendations for developing comparable cross-national measures of migration intensity.
pp. 207-222

Author Hans-Peter Kohler
Social interactions and fluctuations in birth rates

Fluctuations in birth rates in developed countries have been considerably less regular than many explanatory theories suggest. This paper argues that social interaction, ie the dependence of individuals' fertility decisions on the fertility behaviour of other population members, is relevant even in developed countries.

A formal model for investigating the static and dynamic consequences of social interaction for fertility is developed, and its aggregate implications are tested using a Markov switching regression model.

The findings show that social interaction can lead to fluctuations in birth rates that are swift and difficult to foresee, and that these fluctuations are likely to be asymmetric: spells of low fertility have a considerably higher persistence than spells of high fertility. The paper suggests that high birth rates are likely to be followed by spells of low fertility. Transitions from low to high fertility occur at a substantially lower rate than transitions in the opposite direction.
pp. 223-237