Demographic Transition Theory

Correct answer: A. From 14 to 18 per thousand

Explanation: Natural increase depends on the difference between the birth rate and the death rate, not on either rate by itself. At first, the difference is \(40-26=14\) per thousand. After both rates fall, the difference becomes \(28-10=18\) per thousand.

Thus, natural increase rises from 14 to 18 per thousand, so option A is correct. The birth rate falls by 12 per thousand, but the death rate falls by 16 per thousand. Since mortality falls more than fertility, the gap between births and deaths becomes four per thousand wider. Adding the rates would give a different quantity and would not measure natural population growth.

Correct answer: B. Large youthful population and strong demographic momentum

Explanation: When mortality falls but fertility remains high, more children survive than before while many births continue. The difference between births and deaths therefore stays large. Over twelve years, repeated high fertility can produce a very large group of children and young people. This is called demographic momentum: even if fertility later begins to decline, the existing youthful age structure can keep population growth strong for some time.

Option B is correct because the immediate and medium-term result is a large youthful population and strong demographic momentum. The country will not age immediately, since many young people have just been added. Natural increase will not become zero because births still exceed deaths, and fertility will not necessarily fall below mortality. The conclusion follows from the sustained gap between a high birth rate and a rapidly declining death rate.

Correct answer: A. From 23 to 11 per thousand

Explanation: Natural increase is calculated as the birth rate minus the death rate. At the beginning, it is \(31-8=23\) per thousand. Ten years later, the birth rate is 18 and the death rate is 7, so natural increase is \(18-7=11\) per thousand. Thus, the natural increase changes from 23 to 11 per thousand, a decline of 12 per thousand. It remains positive, but the population is growing more slowly than before.

Option A is correct. The fall in the birth rate is 13 per thousand, while the fall in the death rate is only 1 per thousand. Therefore the gap between births and deaths becomes smaller by 12 per thousand. Option B reverses the effect of the changing rates. Option C adds the rates instead of subtracting deaths from births, and option D describes only the death rates, not natural increase. The calculation uses rates, so it does not require the total population.

Correct answer: A. The reproductive-age population is very large

Explanation: Average family size and total births measure different things. Average family size concerns the number of children per household or family, whereas total births depend both on fertility and on the number of people in the reproductive-age population. If there are many women and couples of childbearing age, even a lower average number of children per family can produce nearly the same total number of births.

Therefore option A is the best explanation. A large reproductive-age population can reflect population momentum: earlier high fertility created a large cohort that is now entering childbearing ages. Mortality does not increase births, and fertility rate is not identical to the absolute number of births. Older people generally do not produce more births. Thus declining family size can coexist temporarily with stable total births when the potential parent population is very large.

Correct answer: A. -3 and +2 per thousand

Explanation: Natural increase is calculated from births minus deaths, while total population change also includes migration. Here, the natural increase is \(9-12=-3\) per thousand. The negative sign means that, without migration, deaths would exceed births by 3 per thousand and the population would naturally decline.

Net in-migration is then added to natural increase. Thus, total growth is \(-3+5=+2\) per thousand. In other words, the arrival of more people than leave is large enough to offset the natural decrease and produce a small overall increase. Choice A gives both figures in the required order: natural growth first and total growth second.

Correct answer: B. A demographic-dividend window

Explanation: When fertility falls, the number of children becomes smaller in relation to the working-age population, so child dependency declines. The share of elderly people usually rises more slowly because ageing takes many years. For a temporary period, a country may therefore have a relatively large working-age group and fewer dependants. This situation creates a demographic-dividend window.

The dividend is not automatic. It is an opportunity that can support economic growth when working-age people are healthy, educated, and able to find productive employment. If jobs, education, or health services are inadequate, the opportunity may be weak or may bring unemployment instead. High total dependency is not the best description of this temporary balance, and natural decline is not inevitable. Therefore, option B is correct.

Correct answer: A. Strong social pressure for large families or limited decision autonomy

Explanation: Female education often supports lower fertility by increasing knowledge of contraception, delaying marriage, improving employment opportunities, and strengthening preference for smaller families. However, education by itself may not give women control over reproductive decisions. Strong expectations to have many children, pressure from relatives or the community, limited access to contraception, or dependence on a partner can prevent fertility from falling as expected. Social institutions may therefore weaken or delay the effect of education.

Option A is correct because social pressure and limited decision-making autonomy can explain why education has not produced the expected fertility decline. Option B is too general and false: education does not always raise fertility. Option C reverses the relationship and has no sound basis. Option D is also incorrect because fertility is influenced by social, economic, cultural, and health factors, not climate alone.

Correct answer: A. From 5 to 23 per thousand

Explanation: Natural increase equals births minus deaths. At first, the birth rate is 37 per thousand and the death rate is 32 per thousand, giving \(37-32=5\) per thousand. After the death rate falls to 14 per thousand, natural increase becomes \(37-14=23\) per thousand. Therefore, it changes from 5 to 23 per thousand, so choice A is correct.

The numerical increase in the natural-growth rate is 18 per thousand, because the death rate fell by 18 while the birth rate stayed unchanged. The option correctly gives both the starting and ending natural-increase values. It is not correct to add the rates or to reverse them. The result shows why a fall in mortality, when fertility remains high, can produce rapid population growth.

Correct answer: A. The working-age and reproductive-age population may weaken

Explanation: The birth rate is higher than the death rate, so the country has positive natural increase: \(15-8=+7\) per thousand. However, natural increase is not the same as the future size of every age group. Migration changes the composition of the population, especially when migrants are concentrated in particular ages.

If many young adults leave, the country loses people who are both in the working-age group and commonly in the reproductive-age group. This can weaken the current labour supply and reduce the number of potential parents, which may lower future births. The child population does not have to double, ageing does not necessarily slow, and natural increase does not immediately accelerate. Therefore, choice A is the possible structural effect.

Correct answer: A. Natural increase is zero but social and demographic structure is still changing

Explanation: Birth and death rates of 10 per thousand are equal, so natural increase is zero: \(10-10=0\) per thousand. However, zero natural increase does not mean that every demographic feature has stopped changing. A continuing fall in average family size shows that reproductive preferences, household behaviour, and social conditions are changing. The age structure may also continue to change because different generations are unequal in size and people move through age groups over time. Therefore, option A is the best conclusion.

The country cannot be identified as being in the first stage merely from equal rates. The first stage normally involves high birth and death rates, whereas 10 per thousand is low in comparison. Fertility is related to family size, even though the two measures are not exactly identical; a smaller average family generally reflects lower childbearing. Finally, a stable total growth rate does not imply a completely stable population structure. Natural growth can be zero while composition and behaviour continue to change.

Correct answer: A. Unemployment pressure instead of a demographic dividend

Explanation: A large working-age population can create a demographic dividend only when people can find productive work and have suitable education, skills, health, and opportunities. If job creation is slow, the expanding labour force may instead face unemployment or underemployment. A large youth cohort is therefore a potential resource, not an automatic economic benefit. Choice A correctly identifies unemployment pressure instead of a demographic dividend.

The other choices do not follow from the facts. Elderly dependency cannot immediately become zero, because older people still exist. Fertility is not required to rise merely because the working-age group is large, and population will not automatically stabilize. Economic results depend on policies, investment, skills, and employment capacity. Thus the answer appropriately describes a possible negative outcome.

Correct answer: A. From 17 to 10 per thousand

Explanation: Natural increase is found by subtracting the death rate from the birth rate. At the beginning, the birth rate is 24 per thousand and the death rate is 7 per thousand, so natural increase is \(24-7=17\) per thousand. Six years later, the corresponding rates are 16 and 6 per thousand.

The later natural increase is therefore \(16-6=10\) per thousand. It has fallen from 17 to 10 per thousand, a decrease of 7 per thousand. Although mortality also falls by 1 per thousand, the birth rate falls by 8 per thousand, so the gap becomes smaller. Hence option A is correct; adding the two rates would incorrectly measure total events rather than natural increase.

Correct answer: A. The national average may hide major regional differences in transition

Explanation: A national average combines data from all regions, so it can conceal important internal differences. If rural fertility is twice urban fertility while mortality is low, rural and urban populations may have different rates of natural increase, age structures, family sizes, and positions in the demographic transition. Urban areas may show a later low-fertility pattern, while rural areas may still be experiencing higher fertility and faster growth. The national figure may fall somewhere between them and may not accurately describe either area.

Option A is correct because it warns that regional variation can be hidden by aggregation. Option B is too strong: an average does not automatically represent every region. Option C is false because rural and urban areas can be at different stages. Option D is also false because regional fertility is directly relevant to the national transition and to the interpretation of population trends. Local data are therefore needed alongside the national average.

Correct answer: A. Higher productivity may offset some economic pressures of ageing

Explanation: Low fertility reduces the number of younger people, while high life expectancy increases the number of people surviving to old age. Together, these conditions raise elderly dependency: each working-age person may have to support more older dependants. This can increase pension costs, health-care needs, and pressure on families and public budgets. Rapid productivity growth, however, means that each worker can produce more goods and services. Higher output per worker can therefore compensate for some of the economic burden created by ageing. Option A is correct.

This does not mean that ageing disappears or that pension needs become zero. It means only that technology, skills, capital, and improved work organisation can help maintain total production with fewer workers. The final effect will depend on how quickly productivity rises, how pensions are financed, and how many people participate in work. Low fertility does not automatically reduce output to zero; the size and efficiency of the workforce both matter. Thus, productivity growth is a partial offset, not a complete solution.

Correct answer: A. It may remain approximately unchanged

Explanation: Total dependency combines the burden of children and older people in relation to the working-age population. If one component falls while the other rises by the same amount, their effects can offset each other. This is a comparison of changes, so it assumes the measures are expressed on a comparable basis and that the working-age denominator is not changing in a way that alters the result.

Here, the fall in child dependency is matched by an equal rise in elderly dependency. Their combined contribution can therefore remain approximately unchanged, making option A the best answer. Total dependency would fall only if the child decline were larger, and rise only if the elderly increase were larger. It would not automatically become zero.

Correct answer: A. The same population can be divided into more separate households

Explanation: Population size and the number of households are not the same thing. If the average household becomes smaller, the same number of people may be spread across more homes. For example, people who once lived in a large family may later form separate households as couples, single adults, or small families. Each household may need its own dwelling.

Consequently, total housing demand can rise even when fertility is very low and population growth is weak. Option A correctly identifies this relationship. Low fertility does not always reduce the number of required housing units, because household formation and living arrangements also matter. Children are not the only people who create housing demand, and household count cannot be treated as identical to population count.

Correct answer: A. 0 per thousand

Explanation: The birth rate starts at 14 per thousand and falls by 2 per thousand every two years. Eight years contain four such intervals: 0–2, 2–4, 4–6, and 6–8 years. The total fall is therefore \(4\times2=8\) per thousand, making the birth rate \(14-8=6\) per thousand after eight years. Since the death rate remains 6 per thousand, natural increase is \(6-6=0\) per thousand.

Thus option A is correct. The question asks for natural increase, not the final birth rate. The final birth rate happens to equal the death rate, so there is no natural increase at that point. Option B would result from using only three intervals, and option C would represent an incomplete calculation. This zero is a balance between births and deaths; it does not mean that no births or deaths occur.

Correct answer: A. Positive net migration offsetting natural decline

Explanation: Total population change has two broad parts: natural change and net migration. Very low fertility can make births fewer than deaths, producing a natural decrease. Yet the total population may remain stable if more people enter the country than leave it. For example, positive net migration can compensate for an approximately equal natural loss. In simplified form, total change equals natural increase plus net migration, so a negative natural change can be balanced by positive migration. The wording does not require fertility to be high or mortality to be low; it asks for a combination that can explain stability.

Option A is correct because positive net migration can offset natural decline. Option B would not compensate for the loss: high infant mortality can worsen natural decrease, while zero migration provides no balancing factor. Option C would generally increase the natural decline rather than offset it. Option D would reduce births further and therefore cannot explain stable numbers by itself. Stability may also result from other combinations, but among the given choices, A is the appropriate explanation.

Correct answer: A. National fertility may gradually decline as migrants adopt urban reproductive patterns

Explanation: Rural-to-urban migration changes more than a person’s location. Over time, migrants may experience urban schooling, non-farm employment, higher housing costs, later marriage, better access to contraception, and different ideas about family size. These influences can lead their fertility behaviour to move closer to the lower urban pattern, although the change may take time and may not happen equally for all migrants.

If a growing share of the national population lives in cities or adopts urban reproductive patterns, the national fertility rate may gradually fall. This is a long-term tendency, not an unavoidable immediate result. Migration can affect fertility through social and economic adaptation, while mortality alone does not determine births. Therefore option A is the most appropriate answer.

Correct answer: A. Age structure is shifting from younger toward older ages

Explanation: A fall in fertility produces smaller groups of children entering the population. After some time, fewer children reach primary-school age, so the demand for primary schools may decline. At the same time, low mortality and longer survival allow more people to reach old age. This raises the need for hospitals, long-term care, medicines, and other services for elderly people. Together, these changes show an ageing age structure.

Therefore option A is correct: the population is shifting from a relatively young structure toward an older one. A population explosion would require rapidly high fertility and strong growth, which is opposite to the situation described. A return to the first stage would involve high birth and death rates, and rising infant mortality is not stated. The two service trends are demographic effects of falling fertility combined with improved survival.

Correct answer: A. From 15 to 17 per thousand

Explanation: Natural increase is found by subtracting the death rate from the birth rate. Initially it is \(27 - 12 = 15\) per thousand. Five years later, using the stated rates, it is \(24 - 7 = 17\) per thousand. Although the birth rate falls by 3 per thousand, the death rate falls by 5 per thousand, so the gap between them becomes 2 per thousand larger.

Thus natural increase changes from 15 to 17 per thousand, making option A correct. The question uses the word fertility for the later birth figure, but the calculation clearly treats 24 per thousand as the later birth rate. If “fertility” were intended as a different measure such as children per woman, the wording would be inconsistent; under the supplied rate format, the answer is unambiguous.

Correct answer: A. Structural factors such as housing, childcare costs, employment, and work-family balance also matter

Explanation: Very low fertility usually has several causes rather than one simple financial cause. People may delay marriage or parenthood because housing is expensive, childcare is difficult to obtain, employment is insecure, careers are demanding, or work and family responsibilities are hard to combine. Social expectations and unequal care responsibilities can also affect decisions. A cash payment may reduce some costs, but it cannot remove all these barriers.

Therefore, a policy using only cash incentives may have limited effect, making option A correct. Cash incentives do not always double fertility, and fertility is not determined only by mortality. The statement that low fertility has no social causes is also false. Effective policy generally needs broader support, such as childcare, housing assistance, parental leave, and work-family balance.

Correct answer: A. Demand for long-term care and health services

Explanation: Life expectancy measures how long people are expected to live, while healthy life expectancy concerns the years likely to be lived in relatively good health. If total life expectancy rises much faster than healthy life expectancy, people may spend more additional years with chronic illness, disability, or reduced independence. This changes the kind of support that ageing societies need.

The likely consequence is greater demand for hospitals, medicines, rehabilitation, home assistance, nursing, and long-term care. It does not automatically increase fertility, primary-school demand, or child dependency. The pressure may vary across countries, but among the choices, demand for long-term care and health services is the clearest result. Therefore, option A is correct.

Correct answer: A. The future workforce may fail to develop sufficient human capital

Explanation: A fall in child dependency can create a demographic dividend because families and governments may have more resources available per child, and a larger share of the population may eventually be of working age. However, this opportunity does not automatically produce skilled, healthy, and productive workers. Education builds knowledge and skills, while health investment supports physical and mental ability to work. Without such investment, the future workforce may be numerous but insufficiently prepared.

Therefore option A is correct. Lower child dependency does not by itself guarantee high productivity, so B confuses an opportunity with an outcome. Education is directly related to workforce quality, making C false. Health investment benefits children and working-age people as well as older adults, so D is too narrow. The dividend depends on policies that convert demographic change into human capital.

Correct answer: A. 5 per thousand

Explanation: The initial birth rate is 20 per thousand and it falls by 1 per thousand each year. Over ten years, the total fall is \(10\times1=10\) per thousand. Therefore, the birth rate after ten years is \(20-10=10\) per thousand. The question gives no change in the death rate, so it is treated as constant at 5 per thousand. Natural increase is birth rate minus death rate, giving \(10-5=5\) per thousand. This is still a positive increase, although it is lower than the initial natural increase of \(20-5=15\) per thousand.

Option A is therefore correct. Option B would result from an incomplete or incorrect calculation, such as forgetting to subtract the death rate. Option C would require births and deaths to be equal, which they are not after ten years. Option D is the initial natural increase, not the increase after the birth rate has fallen for ten years. The calculation assumes a steady annual decline and a constant death rate, as implied by the question.