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Ask Dr. Weld 3 — The Demographic Rap: Terms and Definitions


Author(s): Scott Douglas Jacobsen

Publication (Outlet/Website): The Good Men Project

Publication Date (yyyy/mm/dd): 2019/03/17

Madeline Weld, B.Sc., M.S., Ph.D., is the President of the Population Institute Canada. She worked for and has retired from Health Canada. She is a Director of Canadian Humanist Publications and an editor of Humanist Perspectives.In the work of interviewing a professional demographer, the importance of precision in the terminology of the field becomes of utmost importance. Weld provided a summary listing at the outset, as follows:Abortion rate: The number of abortions per 1,000 women ages 15–44 or 15–49 in a given year.Abortion ratio: The number of abortions per 1,000 live births in a given year.Birth control: Practices that permit sexual intercourse with reduced likelihood of conception and birth. Abortion is included in the definition of birth control.Carrying capacity: This is an ecological term that you won’t find in a glossary of demography although it is relevant to humans. Carrying capacity refers to the number of organisms of a given species that can be supported indefinitely in a given environment. (See also Overshoot.)Cohort: A group of people sharing a common temporal demographic experience who are observed through time.Contraception: Practices that permit sexual intercourse with reduced likelihood of conception. Modern methods include the pill, injectable hormones (such as Depo-Provera), implants (small hormone-releasing rods implanted in the upper arm), intra-uterine devices or IUDs, condoms, and sterilization.Contraceptive prevalence: Percentage of couples currently using a contraceptive method.Crude birth rate: Births per 1000 population.Crude death rate: Deaths per 1000 population.Demographic transition: The historical shift of birth and death rates from high to low levels in a population. The mortality decline usually precedes the fertility decline, resulting in rapid population growth during the transition period.Demography: The scientific study of human populations, including their sizes, compositions, distributions, densities, growth, and other characteristics, as well as the causes and consequences of changes in these factors.Doubling time: The number of years required for the population of an area to double its present size, given the current rate of population growth.Emigration rate: The number of emigrants departing an area of origin per 1,000 population in that area of origin in a given year.Family planning: The conscious effort of couples to regulate the number and spacing of births through artificial and natural methods of contraception. Family planning connotes conception control to avoid pregnancy and abortion, but it also includes efforts of couples to induce pregnancy.Fecundity: The physiological capacity of a woman to produce a child.Fertility: The actual reproductive performance of an individual, a couple, a group, or a population. See general fertility rate.General fertility rate: The number of live births per 1,000 women ages 15–44 or 15–49 years in a given year.Growth rate (or population growth rate): The annual rate of change in the size of a population. This change includes the increase (or decrease) from births over deaths and the net migration (immigration minus emigration), expressed as a percentage of the population at the beginning of the time period.Immigration rate: The number of immigrants arriving at a destination per 1,000 population at that destination in a given year.Infant mortality ratio: The number of deaths of infants under age 1 per 1,000 live births in a given year.Life expectancy: The average number of additional years a person could expect to live if current mortality trends were to continue for the rest of that person’s life. Most commonly cited as life expectancy at birth.Maternal mortality ratio: The number of women who die as a result of pregnancy and childbirth complications per 100,000 live births in a given year.Migration: The movement of people across a specified boundary for the purpose of establishing a new or semi-permanent residence. Migration can be international (between countries) or internal (within a country).Net migration: The estimated rate of net migration (immigration minus emigration) per 1,000 population. For some countries, data are derived as a residual from estimated birth, death, and population growth rates.Net migration rate: The net effect of immigration and emigration on an area’s population, expressed as an increase or decrease per 1,000 population of the area in a given year.Overshoot: This is not a term that you are likely to find in a glossary of demography, although it should be there. In population ecology, overshoot occurs when a population temporarily exceeds the long-term carrying capacity of its environment. This situation arises when a species or population encounters a rich and previously unexploited stock of resources that promotes its increase. When the stock is exhausted, the species faces a precipitous population decline or crash. Many ecologists think that the age of oil has sent the human population into overshoot.Population: The total number of persons inhabiting a country, city, or any district or area.Population control: A broad concept that addresses the relationship between fertility, mortality, and migration, but is most commonly used to refer to efforts to slow population growth through action to lower fertility.Population density: Population per unit of land area; for example, people per square mile or people per square kilometer of arable land.Population increase (or population growth): The total population increase resulting from the interaction of births, deaths, and migration in a population in a given period of time.Population momentum: The tendency for population growth to continue beyond the time that replacement-level fertility has been achieved because of the relatively high concentration of people in the childbearing years.Population projections: Computation of future changes in population numbers, given certain assumptions about future trends in the rates of fertility, mortality, and migration. Demographers often issue low, medium, and high projections of the same population, based on different assumptions of how these rates will change in the future.Replacement level fertility: The level of fertility at which a couple has only enough children to replace themselves, or about two children per couple.Rule of 70: You aren’t likely to find this term in a demography glossary but it’s very useful to determine the approximate doubling time of a population based on the annual growth rate. To get the doubling time, divide 70 by the annual growth rate. For example, populations growing at 1, 2, and 3% annually have respective doubling times of 70, 35, and 23 years.Total fertility rate (TFR): The average number of children that would be born alive to a woman (or group of women) during her lifetime if she were to pass through her childbearing years conforming to the age-specific fertility rates of a given year. This rate is sometimes stated as the number of children women are having today.Unmet need: Women with unmet need for spacing births are those who are able to become pregnant and sexually active but are not using any method of contraception (modern or traditional), and report wanting to delay the next child or limit their number of births.Zero population growth: A population in equilibrium, with a growth rate of zero, achieved when births plus immigration equal deaths plus emigration.You can get more information about terminology at these and many other sites: this glossary, I would highly recommend continuing to it, whether for this current in-depth educational article or prior, or future, ones in this educational series on demography. The terms for fields can amount to jargon; however, within the disciplines, these can increase speed of communication and clarity in the productions of the discipline to the experts.Weld noted the ways in which the consequentiality of the increase in the global human population, its growth, is vastly understated as an impactful factor on the outcomes of the future world.

She said, “How many people know that Syria’s population quadrupled from 5 million to 20 million between 1950 and 2010? Once self-sufficient in wheat, Syria has become increasingly dependent on more expensive imported wheat. The 2007–2010 drought was the worst in modern history its water resources dropped by 50% between 2002 and 2008.”

The subsequent or even concomitant crop failures led to hundreds of thousands or mostly Sunni populations moving from rural areas into the coastal cities.Those dominated by the Alawite minority. This may be one of many correlates, or even causes, of exacerbations in the conflicts in the region.

Weld believes the situation may have been better with a more stable population, at the time, of 5 million compared to the 20 million seen in 2010. Or, let’s take the ways in which there is reportage on the problem of underpopulation and overpopulation, a city, region, or country having a population loss is stated in positive terms.”More fuss has been made in the media about Japan’s shrinking population than about the out-of-control growth in many sub-Saharan countries, Syria, Gaza and some others. Yet Japan is coping much better with its decreasing population than the others are with their growing populations,” Weld stated, “As for the use of demographic terms, many people probably couldn’t give dictionary-perfect definitions of a lot of them and many may confuse such terms as fecundity and fertility (both defined above). Nevertheless, the gist of some terms can be intuitively grasped. For example, the definition of total fertility rate (TFR) given above may sound a bit convoluted, but in a nutshell it is the average number of children that women of a given country or region have in their lifetime. Most people would probably get some sense of that from the term itself.”

She covered 6 areas in this session in-depth. The first is population density. This is simply the number of people in a given unit land area. Tokyo, Japan, is more densely populated than probably any area of Canada. That is, Tokyo has a higher population density than Edmonton, Toronto, or the numerous small towns through Canada.

Weld dispensed of the myth that Canada has infinite space for the inclusion of more and more people. Newcomers tend to congregate in the cities rather than attempting to make a living within the spaces on the outskirts of the societies, or in the tundra. This is a fact of the outcomes of the immigration policies in Canada.With the rapid increases in the growth of the population, cities in Canadian society continue to experience stresses on both infrastructure and social services while losing biodiversity, wildlife, and farmland. The second topic was population growth and population growth rate. It is the increase or the decrease in the total numbers of the population.

It is a modestly more complicated calculation, but, nonetheless, it comes to a reasonably straightforward calculation of the births minus the deaths and the immigration minus the emigration. Canada’s fertility rate is 1.6. The replacement rate of the population is 2.1. That means Canadian citizens, on the whole, are not replacing themselves.

The population of Canada can retain its size due to the face that there is a significant amount of immigration into Canada to maintain the population size.Weld said, “A population can be growing in absolute numbers even if its rate of growth is slowing down. The growth rate of the global population has in fact slowed down a lot in the past several decades. This has led to a perception among many (including in the media) that the problem is solving itself. But the absolute number of people being added annually has gone up, because the size of the population is bigger. This is illustrated in the table below. It is the absolute number of people that puts pressure on the environment. Yet many people seem to think that a decreasing growth rate solves the problem.”

The third section was the Total fertility rate or the TFR. Weld talked about the average number of women per child in a country or region throughout said woman’s lifetime. The TFR was 2.5 in 2018 based on UNFPA’s State of the World Population. There is a ‘plummet’ of the TFR over the last decades. According to Weld, this is a good thing.

It is indicative of the overpopulation problem, or 0.4 above 2.1, solving itself. This is all part and parcel of a continuing problem of the decrease in the number of people in the world per year compared to if the TFR was increasing or maintained itself from the previous year. The growth rate, not the total population, of the world is on the decrease.

However, this is not the whole story, Weld said. Because this is simply a coarse metric not taking into account the global population and the population differences when comparing regions or countries.

“For example, the countries defined by the UNFPA as ‘more developed regions’ have a TFR of 1.7, while those in the ‘less developed regions’ have a TFR of 2.6, and the ‘least developed countries’ have an average TFR of 4.0. The TFR of Somalia is 6.1 and of Niger 7.1,” Weld explained, “Many, probably most, or the countries with very high TFRs are failed or failing states, with emigration pressures that are already huge and that will likely only worsen with time. Africa’s population is projected to explode from 1.2 billion today to 2 billion by 2050 and over 4 billion by 2100.”

The fourth part was contraceptive prevalence versus unmet need. Contraceptive prevalence is the percentage of couples who are actively and properly using a contraceptive method (actively and properly, hopefully). Unmet need are women who remain capable of pregnancy and are sexually active but do not want to become pregnant and are not using contraceptives.

Sometimes, there is a correlation between contraceptive prevalence and unmet need. Although, there are times when the want of a large family does not reflect lack of access to contraceptives.

Weld stated, “That is why the completely hands-off approach taken at the 1994 International Conference on Population and Development (Cairo conference) with regard to promoting small families represents a huge failure, in my opinion. People were to ‘freely and responsibly’ decide on the number and spacing of their children, but this idealistic thinking did not take into consideration the strong influence of cultural norms, religion, and tradition on desired family size. The UN developed no programs to educate people about the impact of population growth and to promote smaller families. (Unlike, for example, programs to promote and implement child immunization that were developed right after the World Health Organization was created.)”

A stark example given by Weld is Kenya, where there was an understanding of married women (96%) and their husbands (98%) of modern contraceptive methods. 40% of the women did not intend to use contraception ever. 8% of the non-married women gave the reason for their not wanting to use contraception, which was, quite simply, to have more children.

“Among the reasons given for not using contraception by women who were not pregnant and did not want to become pregnant, only 0.8% cited lack of availability of contraceptives, and 0.4% cited cost. The top four reasons among those who are still fecund: (1) concern with the medical side effects of contraceptives (31%); 2) religious prohibition (9%); (3) personal opposition (8%); and (4) opposition from the husbands (6%). (The information on the DHS survey is from a December 2012 paper by William Ryerson of the Population Media Center.) In a 2015 presentation by Dr. Ryerson summarizing the major reasons given for non-use of contraceptives in over 30 rapidly growing countries, lack of access was the main reason in only 1% (a single country) or below of the people surveyed in every country,” Weld said.

The big reason being fear of side effects. This was followed to varying degrees depending on the opposition of the spouse, the health concerns, the religious prohibition, and the lack of knowledge. The changing of fertility rates, especially the high ones, will have to take more into account than the simple notion of contraceptive knowledge leading to an increase in the use of the contraceptives

The fifth section was the population projections based on the assumptions of fertility, migration, and mortality. The fecundity of the population; the transfers into and out of the population in a specified bounded geography; and the deaths of the population.

The projections or the estimates of the population only become so good as the assumptions plugged into the calculations and the terms used in order to gather the data according to the definitional constraints. Research is tough. This explains the reasons for the differentials in the lower, moderate, and higher projections as to the future population of the world.

Weld said, “…there was optimism that the world population would peak at 9 billion before 2100 and then decline, but current projections are for a still-growing population of over 11 billion in 2100. Almost all of the increase in the projected global population is because fertility rates did not fall as quickly in sub-Saharan Africa as had been assumed. In 2004, the United Nations projected a population for Africa in 2100 of 2 billion, but by 2015 had upped its projection for 2100 to 4 billion. The increase in the projected population of sub-Saharan Africa accounted for almost all of the increase in the projected global population.”

The decrease in the TFR is one consideration. But this is one among many different considerations in the world. One of the assumptions was that there would be a transition of the demographics for the developing countries. Those that would automatically happen around the world as a matter of natural science or inevitable history. It did not happen in sub-Saharan Africa and some other countries.

“One thing that population projections do not take into account is the depletion of resources. The human population may not undergo the gradual decline that demographers foresee based on their assumptions of fertility decline, but a rather more abrupt crash based on resource shortages, starvation, war, the outbreak of diseases resistant to antibiotics, and other dystopian factors,” Weld said.

The sixth section of the interview with Weld was the demographic transition or the demographic transition theory (DTT)/model (DTM). Weld see the DTM or the DTT as the main reason for individual global citizens becoming complacent about the mostpressing problem of our era, which is the laziness towards too many people and too little resources.

Weld stated, “The demographic transition theory posits that societies will transition from having high fertility and high mortality to low fertility and low mortality as a natural consequence of socioeconomic modernization. The transition is usually divided into four stages. In the first stage, the population of a society is fairly stable because the high birth rate is balanced by a high death rate. In the second stage, as the society develops and health and hygiene improve, the death rate falls but the birth rate remains high, leading to rapid population growth. In stage 3, population growth starts to decrease as the birth rate falls due to better economic conditions, more education and an improvement in the status of women, and more access to contraception. In stage 4, both the birth rate and the death rate are low, and population growth is negligible or even declining.”

It isn’t based on inaccuracies if taken in the abstract, as there was important developments in the work towards transitions for the demographics of a nation or region seen in Europe from the middle ages to the more modern technological and industrial societies. The ongoing and damaging mistake in the reasoning is the application of the conditions of middle age Europe to the contexts of other regions in the modern world now.

Weld pointed out that the “DTT was embraced by the 1987 Brundtland Commission on sustainable development. Sustainable development would be achieved through economic growth in developing countries, social equity, and environmental protection. But how would these be achieved without controlling population growth? The demographic transition would take care of it because people would have fewer children as they became richer. The same thinking guided the International Conference on Population and Development in Cairo in 1994.”

Since 1994, the global population has grown from 5 billion to 7.6 billion. The hoped-for continued developments have stalled to with increases in the population and the subsequent damage to both the natural world the biodiversity of the natural world. This is where we find ourselves at the crossroads of theory and reality with reality repeatedly standing right in front of our faces awaiting an acknowledgement.

“Much emphasis has been placed on things like education for girls and economic development to indirectly address population growth. There is indeed a negative correlation between the level of female education and the TFR, and education and equal opportunities for girls and women are desirable in their own right. But, as Dr. Jane O’Sullivan has shown, expecting an increase in wealth to lead to a reduction in fertility is putting the cart before the horse,” Weld stated.

The fertility decline is associated with increases in wealth and with an increase in per capita wealth comes when the birth per women hits between 2 and 3 children. Girls’ education was “neither a pre-requisite nor a sufficient measure” to set forth the decline in the levels of global or local fertility. However, fertility decline was important for sustained economic growth. O’Sullivan explained how the best contraception is not development, as per the adage.

Weld firmly stated, “There is an urgent need to make population growth an issue in its own right. Some countries, such as Bangladesh and Thailand, have done so. But most have not, nor has the United Nations made population growth a central part of its Millennium Development Goals (launched in 2000) or its Sustainable Development Goals (launched in 2016). The American population activist Rob Harding has proposed a UN Framework Convention on Population Growth, in which every country would take responsibility to bring its own population to a sustainable level. Other countries could help rapidly growing countries to achieve a sustainable population, but would not be expected to take in their surplus population (which appears to be the objective of the UN’s Global Compact on Safe, Orderly and Regular Migration).”

The DTT simply received too much credit for insufficient reasons. The seventh and final section in the responses by Weld were the Overshoot. It was based on William Catton’s book entitled Overshoot. It was published in 1980 while still remaining relevant.  In it, the basic argument that every decision-maker who believes in infinite growth within an infinite planet are making a catastrophic mistake because the world exists with limited resources on a finite planet, or, more appropriately framed as a counter to the framing before, an infinite growth within an infinite planet can lead to catastrophic conclusions in argument and in reality. This echoes the sentiment of Malthus, not as extreme but, simply put, in spirit and result if not taken seriously to some degree.

“The gist of Catton’s book is that oil provided the energy for humans to draw down the world’s resources, which has allowed the human population to greatly exceed the long-term carrying capacity of the Earth (i.e., to go into overshoot). When resources become scarce or run out, there won’t be enough to support the human population, which is likely to undergo a steep decline or a crash. The world is an ecosystem with limits to growth and nature will have the last word,” Weld stated, “It took until 1804 for the human population to reach one billion. It increased to 2 billion by 1927, and 3 billion by 1960. The next three billion were in 1974, 1987, and 1999. In 2011, the human population reached 7 billion, and is now over 7.6 billion. Our population increases by 1,000,000,000 every dozen or so years. There is an eerie parallel of this spectacular increase in the growth of the reindeer population on St. Matthew Island, a remote outcrop in the Bering Sea, 300 km from Alaska.”

As noted about the reindeer on St. Matthew Island, the end-result can be troublesome for both the human population and the ecosystems on which human beings and other fauna and flora need to survive. The food supply, the lichen, by the reindeer was consumed in a short time, only a matter of a couple decades or so, and then when the researchers visited the island once more; they found the island littered with reindeer skeletons. The health of the reindeer was worse. These are the dynamics of growth of an organism population in a finite area of land with a finite amount of resources.

Weld concluded, “It’s true that the Earth is bigger than an island, and humans are smarter than reindeer, but we are exploiting resources globally on a colossal scale and the negative impacts of this drawdown of resources are becoming ever more evident. We would be wise to take heed.”


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