Man in Bangladesh, the nation as a whole," as a wise man once put it, "is the principal resource of Bangladesh." Not just here, throughout human history, a teeming population has been synonymous with 'prosperity, stability and security'. Only lately, since the industrial revolution in England, did population come to be viewed as a problem. The number of people in Bangladesh too, was habitually viewed as a problem, even the problem in terms of other resources available. This wise man of our nation, Professor Abdur Razzaq, however, thought differently. "I am not persuaded," he asserted, "that the first step in the solution of the problem is an attempt to limit the number, birth control and family planning and all that." More significant than the number as such is the structure or composition of a population, according to Abdur Razzaq, whose public lecture 'Bangladesh: State of the Nation' remains to this day an unparalleled document of wisdom. 

Writing in 1980, he asserted, "The nation contains 80 million souls. Of this 10 percent or so would be in the age group of 8-23. What the nation has in store for itself depends on what the society does for this rather small percentage of its population." It was in this area that he thought the situation occasioned greater pessimism than any other did in Bangladesh as in other nations of South Asia. Countries in East and South East at the time, he observed, were already following a different path. "The prospects of the nation are in the details of the plans and programmes concerning this rather small section of the population," he concluded.

Lived experience of the nation, four decades later, seems to vindicate this wisdom. As demographic studies now show, conditions have changed for the better. Incidence of poverty, as measured by headcount ratio, by conventional (national) poverty line, declined to 31.5 percent by 2010, at a time when population growth rate is nearly 2 million per year in a nation of 160 million. Dependence on foreign aid has reduced from 88 percent in 1972 to 2 percent in 2010. Data for the last five years show GDP growth rate over 6 percent, reaching 6.7 percent in 2012, with a limp to 6.2 percent in 2014. Worldwide economic slowdown notwithstanding, it sustained a high growth trend in Bangladesh. It could have achieved better had we utilised the work force more efficiently.

According to a 2015 report, the Ministry of Planning rejoices in the fact that population density of the country as a whole has reached "unprecedented levels in human history with the exception of very few small city-countries as Singapore, Malta and Bahrain". In addition, the document highlights, "Bangladesh is crossing a one-time demographic window of opportunity that can be transformed into a demographic dividend," provided the right investments are made, especially on young people, now consisting 30 percent of the whole population.

By the time our total population reaches 200 million, say by around 2050, the nation would have added another 40 million, even as fertility rates continue to decrease below 'replacement level,' (i.e. 2.1 percent) which it has already reached.

When the proportion of the population in labour force age is increasing, it provides a one-time 'demographic window of opportunity,' or better a 'demographic dividend,' for investment in human resources. As measured by proportion of the population in labour force ages (defined as falling within 15-59), this 'window' is projected to open widely in Bangladesh over the next 10-20 years, admittedly a rather short period. Likewise, 'dependency ratio' too can be expected to drop sharply over the next 20 years before rising again with the growth of the elderly.

'Demographic dividend,' is characterised by availability of more people in the productive age group. As child mortality declines, families tend to be happy with fewer children, leading to a further fall in total fertility rate. At earlier phases, with more people of working age, the number of children and senior people tend to be fewer in the family. This phenomenon, 'dependency ratio,' is presently reduced to 52.2 percent.

In Bangladesh, demographic dividend found way in 1990 and this may continue to 2030. At that end, increasing costs for the aged becomes a concern for both the family and the nation. One learns from the experience of many developed nations, say Japan, UK, US and others. 

Is Bangladesh ready to reap the fruits? The nation is now 160 million strong, assuming a growth rate of about 1.6 -2 per year since 2011. A vast majority belongs to the productive age group 15-59. The prime productive age group, defined as 25-54, is now 38 percent. The net effect of current policy, unfortunately, is counter-productive. It is encouraging 'two nations within the nation,' between those who have and those who have not profited from public expenditure.

As experience shows, the general fear of overpopulation is now deprived of all foundations. The relation of productive power to population is now back on the table. Malthusian projections of population growth in geometrical progression and the growth of productive power of land in arithmetical progression have become irrelevant. It went wrong because science progresses as part of the demographic dividend. Engels once aptly said, "The area of land is limited–that is perfectly true. But the labor power to be employed on the area increases together with the population; and even if we assume that the increase of output associated with this increase of labor is not always proportionate to the latter, there still remains a third element – which the economists, however, never consider as important – namely, science, the progress of which is just as limitless at least as rapid as that of population." 

The writers are anthropologist at Centre for Asian Arts and Cultures, and public health project manager at EngenderHealth Bangladesh.