Two posts related to population

The usefulness of the DTM; and visa rules

[Here are two posts related to population. Firstly, one on a popular model taught in UK schools. The second is more contemporary, giving a brief overview of how some countries are opening their borders to migration, whereas others are restricting immigration.

Other posts I have written on the Population topic can be found in my archive:

Population futures here.

UK life expectancy here.

An essay answer on population growth and Malthus here.

An answer to a 9-mark question here.

UK birth rates here. ]

How useful is the DTM?

A model is a simplified representation of how real-world systems operate. One such model is the Demographic Transition Model (DTM). It seeks to represent patterns of population change over time that are evident in different countries. The model continues to be part of geography specifications. I am not going to outline the main features of the model here – textbooks do this well, and students have drawn it from Year 7 to Sixth Form in schools across the UK.

What does the DTM do?

The DTM describes a country’s transition through 4 (and then later 5) stages of population change, linking fertility and mortality to overall population growth. It also states that demographic transition takes place alongside social and economic change. The DTM proposes that reductions in birth and death rates and stabilisation of population growth are associated with economic development.

The DTM is said to accurately describe patterns of fertility and mortality for countries around the world from the eighteenth century (northern and western Europe) to the late twentieth century (sub-Saharan Africa). While some countries, including the UK, have passed through the traditional DTM to what is known as the ‘fifth stage’ (of low fertility, low mortality and natural population decline), others such as Nigeria, Kenya and Afghanistan today have high fertility, falling death rates and natural increase (more births than deaths), representing stage 2 or 3 of the model. Other countries, such as South Korea, show ‘lowest low fertility’ – in 2023, an average woman in S. Korea had only 0.8 babies during her lifetime. However, this latter situation does not feature in the DTM.

How useful is the DTM?

An important consideration of the value of the DTM is whether it is thought of as a descriptive model or an explanatory tool. Explanatory models propose why things change not only how things change. I would suggest that we should be cautious of employing the DTM to explain population change. Why do I think this?

Firstly, the DTM represents only part of the picture of population change. Any holistic explanation of population change must look beyond the model. Population change for a specified place and time can be defined by the Demographic Balancing Equation:

Future population = Population now + [Births - Deaths] + (Immigration - Emigration)

The DTM does not include migration and therefore assumes nationally closed populations. Migration not only affects the overall population size at the time of migration, but it also has longer-term demographic effects on the age structure of the population (because migrants tend to be younger than average) and, in turn, fertility and mortality rates.

Secondly, despite being generally applied to countries, the DTM is not geographical. The model is not concerned with smaller places and connections between these places. The DTM presents a static model of place, emphasising the importance of time over place. Recent studies of population growth have examined geographical variations in births and deaths. For example, geographers have assembled evidence to show how you can travel a few stops on London’s underground line and yet travel a decade in average life expectancy.

Thirdly, fertility rates vary between countries and within them. For example, there are parts of Portugal and southern Italy that have fertility of around 1 child born on average to each woman during their lifetime (well below the ‘replacement level’ total fertility rate of 2.1). In contrast, in northern France and central Finland there are areas with above replacement fertility. Understanding why regions or communities differ in their fertility leads us to consider the contemporary social contexts in which people have children.

The complexity of understanding these variations outlines the limitations of the DTM as an explanatory model. Contemporary patterns of low fertility, delayed childbearing/marriage, and complex families (for example stepfamilies or blended families) are more relevant today than in the past. Economic, social, political, cultural and geographical factors are all important for understanding why levels of fertility vary between people and places.

The DTM is a descriptive tool. Even for parts of the world where fertility and natural growth remain high, we cannot assume historical European patterns will be followed. The global pandemic in 2020-2021 is an example of how predictions can be disrupted. This was a global shock that had repercussions for population change - and demographic transition - that the DTM does not capture. The long-term impact remains to be seen but to understand the patterns, drivers, and consequences of future population change, more attention needs to be paid to the specifics of time and place.

Varying visa rules

To attract new talent and counter ageing populations, many countries are liberalising their visa regimes whereas others have sought to restrict them. Here is a synopsis of how a variety of countries (not UK) are doing this:

·         In South Africa, the new government announced plans to reform its visa rules to end a backlog of thousands of applications to enter the country. While unemployment stands at a high of 33%, a lack of skilled workers threatens the expansion plans of foreign investors such as the car maker Volkswagen. ‘This country’s economy will never grow if we don’t open our doors to people who want to lawfully come here and make a contribution and help us get on track’ Home Affairs minister Leon Schreiber has said.

·         With a population of 1.4 billion, India has a lot of domestic talent. However, the government is seeking to attract a specific type of skilled worker, namely Chinese engineers and technicians, who are needed to install machines and train Indian workers. The government is finalising rules to fast-track visas for Chinese engineers.

·         South Korea has its own challenges with a shrinking and ageing population. The country is not only planning visa reforms, but other policies designed to increase the world’s lowest fertility rate.

Short-term visa applications

Other countries are looking for short-term visitors who help boost trade in services - tourists. China has introduced a 15-day visa exemption for citizens of Australia, New Zealand and Poland and pledged similar exemptions with Malaysia. Visits to China by foreigners rose by 153% in the first half of 2024 from the previous year, with more than half of these travelling under visa-free rules.

Thailand has granted visa-free entry for citizens from an additional 36 countries and territories, increasing the number of visa-free entries to 93 countries and territories. Visitors are allowed to stay for up to 60 days, while another there is another visa category for digital nomads - people who can also work from a holiday location - allows stays for 180-days.

The counterview

In some countries where immigration has long been seen as the solution to demographic shortcomings, some visa-easing plans have been restricted and indeed there have been some reversal.

• Canada’s government is reviewing how many long-term visas it grants to foreign students.

• Australia has raised fees on student visa applications.

• Portugal plans to tighten immigration rules whilst facing a backlog of more than 400,000 visa inquiries.

• Singapore’s government introduced a new points-based system and minimum salary threshold requirement which will come in effect in September 2024.