Population Challenges for Bangladesh

 

Abstract

Bangladesh currently has a population approaching 150 million and will add another 100 million before stabilizing, unless fertility can soon drop below replacement level. This level of fertility decline will require a change in marriage patterns, which have been minimal so far, even with increasing female schooling. It would also benefit from a long-awaited shift to long-term contraception. In addition to the consequence of huge population size, the density of population is already five times that of any other ‘mega’ country (>100 million), a very challenging situation for an agricultural society. Most of the future growth will be urban, increasingly in slums. Numbers of young people will not increase, but numbers of older people will increase 10-fold this century, creating a large burden on the health system, especially for chronic illnesses. High density of population means that agricultural land is virtually saturated, with very limited capacity to expand food production. Climate change may have dramatic impacts on agriculture, through flooding and drought resulting from weather changes and geopolitical influences on transborder rivers. Rising sea-levels and consequent salinity will affect crops and require shifts to alternative land use. Serious long-term planning is needed for meeting the growing needs of the population, both for distribution and consumption.

Key words: Ageing, Age factor, Child survival, Climate change, Family planning, Fertility, Population growth, Urbanization, Bangladesh

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CURRENT POPULATION SITUATION AND FUTURE GROWTH

The Bangladesh population in mid-2007 was around 147 million. The precise figure depends on assumptions about rates of growth since the adjusted census figure of 129,247,233 for 22 January 2001. The Bangladesh Bureau of Statistics (BBS) indicates an average rate of natural increase of 1.5% annually since the census. However, these figures from the BBS are almost certainly under-estimates of crude birth rate (CBR) (20-21/1,000) and crude death rate (CDR) (5-6/1,000). The BBS rates would project a population of just over 141 million whereas the Population Reference Bureau (PRB) rate of natural growth of 1.9% per annum is more likely—based on assumed CBR of 27/1,000 and CDR of 8/1,000, resulting in a projected population of 147 million.

Population projections

A more important question is what the future popu- lation growth will be. Until the United Nations Population Division (UN PD) released the 2004 revision of population projections for all the countries of the world, there was a general agreement that Bangladesh would reach 218 million by 2050 and finally stabilize at around 260 million in mid-next century (1). However, the 2004 revision by the UN PD proposes a pessimistic upgrading of the 2050 figure to 243 million as a consequence of the decade-long fertility plateau (1993–2002). This seems excessively high. The PRB estimate is 231 million for mid-century, which is more realistic, although a new set of Bangladesh population projections should be produced, taking into account the recent demographic events. Whatever the details, it can be seen in Figure ​Figure11 that Bangladesh is only halfway along the S-curve of the ‘demographic transition’ from a historically-stable population size of around 25 million to a final size of 10-fold larger.

Fig. 1

Population of Bangladesh: 10-fold growth in two centuries

Key messages

• The density of the Bangladesh population is much higher than any other mega country.
• In 2007, Bangladesh was only halfway up the population growth curve and will reach more than 250 million later this century.
• Most of the increased population will be urban, and much of Bangladesh will essentially become a city state.
• The year that Bangladesh reaches replacement fertility is not as critical lowering fertility to less than replacement. Other Asian countries have accomplished this.
• The number of children born each year is now stabilized at slightly less than 4 million.
• Age of marriage has not increased in Bangladesh as it has in other Asian countries.
• The elderly (>60 years) will grow in population from 7 to 65 million this century, and this will make many demands and different demands on the health system.
• There has been a major reduction in overall numbers of child deaths over the last three decades. Part of this reduction is due to reduced fertility, and part is due to child-survival interventions.

The UN projection would require an average annual growth rate of 1.29% from today to 2050. As the CDR will not fall below 8/1,000, the CBR would have to remain, on average, at least 21/1,000 [The population growth rate (natural increase, not including international migration) is the difference between CBR and CDR, expressed as a percentage, not per 1,000]. This is unlikely as even if the TFR remains at a plateau at replacement level through 2050, the population-ageing process will bring the CBR down below 20 within a decade or so. Simultaneously, the population-ageing process will start to push the CDR beyond 8/1,000 from around 2020, which will further reduce the population growth rate.

Replacement fertility

It is worth noting that the exact year in which replacement fertility is achieved is not of great importance. What is potentially of much greater importance is whether or not fertility can be brought below replacement fertility. For example, if fertility stops declining on attaining replacement level, the final population will continue to increase for another century and add at least 100 million. However, if fertility declined through replacement (i.e. TFR around 2.2) to the current level of Thailand (TFR around 1.8), the final population could stop growing at 205-210 million, some 50-55 million lower than otherwise will be the case.

Age structure and population momentum

A demographic change that has major implications is the rapid fertility decline of the 1980s. The first impact has been to slow population growth, but it has resulted in a gradual change in age structure. An encouraging feature of the change to, or ‘ageing’ of the age structure, is the fact that the number of children and young people aged less then 15 years—now at 47 million—will never increase. Throughout this century, that number will remain stable, which should assist planners in building an education system.

A related feature of this age structure is that, with current low mortality rates, many of those 47 million young people will survive and pass through the reproductive years and contribute to the continuing population growth, even if replacement fertility level is attained within a decade [Every 5-year delay in achieving replacement fertility adds 3% to the population projection]. To illustrate the significance of this, there are currently about 45 million young women in the reproductive ages (15-49 years). By mid-century, this number will have increased to 75 million, as over 90% of young people who survive to age 15 years will survive to age 50 years.

Determinants of future population growth

Can changes in any other determinants of population growth play an important role in what future population growth will be in Bangladesh? The major components include fertility, mortality, and migration.

Fertility 

Following a dramatic and precipitous decline in the 1980s from almost seven children per woman (late 1970s) to just over three children per woman (early 1990s), fertility has been stagnant for a decade. Demographers found it difficult to predict when a decline would restart. The usual indicators of future behaviour, such as reported ideal family size and unwanted fertility, did not indicate a very substantial unmet need for fertility control; nor did the gradual decrease in gender preference, which still suggested a desire for at least one boy and one girl, which tends to result in an average fertility (TFR) of around three children, even if 70% of parents say that they only want one of each.

The only indication of a coming restart of fertility decline was the continuing fall through the 1990s in the less widely-used parity progression ratios. Indeed, the Demography and Health Survey (DHS) 2004 showed a minor drop in TFR to 3.0, which was of borderline significance [The TFR from BDHS 1999/2000 was 3.308 (3.159-3.457), and from BDHS 2004, it was 3.028 (2.894-3.161), meaning the 95% confidence interval barely touched at 3.16]. The latest DHS, in 2007, has confirmed the resumption of the decline (Fig. ​(Fig.2),2), with a further fall to 2.7, still half a child above replacement fertility. This author suspects that fertility will continue to fall gradually to a TFR around 2.5, then possibly a plateau again for some time, as some other countries have seen. There is still reason to be hopeful that replacement fertility will be achieved by 2015, as was the target for the 1994 World Bank population projections, although five years later than the 1996 UN PD projections.

Fig. 2

Trends in fertility, Bangladesh, 1980–2007

Family planning

A puzzling feature of the fertility plateau was the fact that contraceptive prevalence rates (CPRs) continued to rise steadily throughout the 1990s, from 44.6% (1993/1994) to a peak of 58.1% in 2004, followed by a slight fall to 55.8% in 2007, due to a fall in traditional methods. Experience from other countries suggests that such a rise in the CPR would produce a concurrent decline in fertility. Recent studies have not satisfactorily explained this paradox. An examination of the range of fertility determinants indicates that potentially important factors, such as delayed age at marriage, do not appear to have played a counter-balancing role in the Bangladesh case; nor have less powerful factors, such as postpartum amenorrhoea linked to breastfeeding, changed in any significant way. There has been a gradual shift in the use of permanent and long-term contraception towards a greater dependence on temporary methods, but this is mainly among older fertile women who are not contribu- ting much to overall childbearing rates. One possible factor may be that adoption of modern contraception has gradually been substituting for reliance on induced abortion. This pattern, seen in Matlab (2,3), appears to require quite high levels of CPR before a substitution begins to take place. This may well be context-specific and presumably depends on the level of fertility and the speed of the decline.

Are new indicators needed to monitor child survival