This book shows that the patterns in family, socioeconomic and demographic changes in Southeast are complex and heterogeneous. The size of the population ranges from one of the largest countries in the world—Indonesia that has about 260 million—to one of the smallest countries in the world—Brunei that has less than half a million people. Most countries have experienced growth that has doubled or tripled their population since 1960. There have been impressive though uneven gains in the economic development in this region—ranging from countries among the world’s richest and most educated such as Singapore to the world’s poorest—Timor-Leste, Laos PDR, and Cambodia. Countries such as Cambodia, Lao PDR, Myanmar, the Philippines and Timor-Leste still have very low GDP per capita and high poverty rates. Gains in education and health have been similarly remarkable but varied with Myanmar, Cambodia, and Lao PDR still have less than 60% of children enrolled in secondary schools. Indonesia, Thailand, Vietnam and Cambodia have less than 30% of those aged 25 and above completed at least upper secondary education. Gender inequality in education has decreased with half of the countries having more females than males enrolled in tertiary education. In general, the level of socio-economic development and demographic transition in Southeast Asia fall between East Asia and South Asia.

Age at marriage has become later for all countries, but the range is wide; for females, it ranges from close to 30 in Singapore to early 20s in Laos PDR, Cambodia and Indonesia. While marriage remains near-universal in some countries (e.g. Laos PDR and Vietnam), we also see a substantial and growing segment of the population remains single in some countries—for example, more than a quarter of females aged 30–34 remain single in Myanmar and Singapore. In countries like Thailand and the Philippines, there is a substantial proportion of women in consensual unions.

Fertility rates have declined rapidly in all countries. Currently, about half of the countries have above-replacement fertility with Timor-Leste having the highest level (5.1 in 2014) and the other half have below-replacement fertility with Singapore having the lowest fertility level (1.2 in 2014). As a result, the overall TFR in Southeast Asia is at about the replacement level of 2.1. Adolescent fertility rates in general has been declining except for Vietnam and the Philippines. Fertility transition is still in progress with wide variations in the factors that shape this process over time and across countries. We also see a substantial proportion of women remain childless in Singapore and Thailand.

Due to the lengthened life expectancy and decline in fertility, countries in this region are growing older. Singapore in particular will enter the “super-aged population” stage (over 20% of the population aged 65 and above) within a decade, seeing a rapid increase of those 80 and above who will demand significantly greater health care needs. Fortunately, Singapore has better financial resources and human capital to address such challenges than other countries in this region. Thailand and Vietnam will also face the challenges of an aging population but have less adequate resources to handle these challenges. For these three countries, the speed of population aging is very fast, taking about 20 years or less to transition from an aging society (where 7% of the total population is aged 65 and above) to an aged society (where 14 of the total population aged 65 and above). However, other than Singapore, Thailand, and Vietnam, most countries are still relatively young now in this region. Nevertheless, because of the rapid decline in fertility in the past few decades, the speed of population ageing in the next few decades in this region will be much faster than that experienced in Western countries. These countries, however, need to improve the education attainment and human development in the population. Although education, particularly, women's education, has increased significantly, some countries still have more than half of the youth population not enrolled in secondary schools (e.g., Myanmar and Cambodia). Most countries have female employment rates higher than 50% in 2015 except Malaysia and Timor Leste.

As predicted by family sociologist William Goode (1963), family sizes have become smaller in this region. However, it is important to note that nuclear families were prevalent long before industrialization in many Southeast Asian countries. Furthermore, a majority of older adults in this region still live with or near their children. Extended families remain prevalent (e.g. 40% in Thailand in 2000) and have increased in some countries (e.g. Vietnam, Indonesia, Thailand, and Cambodia) in recent years. Alternative family forms have started to emerge such as single-parent families, step families, and on-person households. These patterns indicate that the Euro-centric assumption of the extended family as a starting point of global family change and that all family forms will eventually converge to nuclear family is incorrect.

The influence of structural and ideological changes caused by modernization and globalization on family and demographic changes is evident. However, there are changes that cannot be explained by modernization such as the high singleness rate in Myanmar despite a relatively low development and the low cohabitation rate in Brunei and Singapore despite the high development level, and high cohabitation rates in Thailand and the Philippines. The diverse culture by ethnicity and religion, kinship system, and policies in different countries (discussed in greater detail in other studies) also account for the heterogeneity seen in Southeast Asia.

Signs of the “second demographic transition” remain limited thus far in this region as cohabitation is not common (except in Thailand and the Philippines), divorce rate is relatively low in even high-income countries such as Brunei and Singapore, and out-of-wedlock births are rare even in one of the world’s most modern countries—Singapore—although the total fertility rates have dipped below the replacement level since 1975 and are currently among the lowest in the world. It should be noted that fertility rates fell in a context where the majority of the population in Singapore were religious. (According to the 2015 Singapore General Household Survey, 81.5% of Singaporeans have a religion.) This is at odds with the argument that secularization as a result of a decline in religiosity leads to postmodern family behavior such as below replacement fertility and non-marital childbearing. In the case of Singapore, such trends are strongly influenced by state policies that aim at upholding the practices of “parenthood within legal wedlock” and the two-parent family type. The ultra-low fertility and high proportion of never-married and childless women in Singapore reflect a combination of the high living cost, rising aspirations for self-development, changing attitudes about marriage and parenthood, and the slow institutional adaptation to the rapid changes in women’s status in the last few decades, which has made family–work life balance difficult for many young people to achieve. Singapore’s experience illustrates the powerful influence of social policies in consciously striving to avoid Western family values and behaviour. In other countries, family planning policies and health and welfare policies also play important roles in explaining the family and population changes in those countries.

There are some areas for concern for children and youth including the high youth unemployment rates in countries such as Indonesia, the Philippines, and Timor-Leste, especially for young women. The unfavourable conditions in the labour market will affect young people’s demographic behaviour such as marriage and parenthood. Some Southeast Asian countries such as the Philippines and Laos PDR have relatively high prevalence of low-birthweight babies. Timor-Leste, Cambodia, Laos, and Indonesia have a high prevalence of child wasting. Paradoxically, Indonesia also has the highest overweight rates for children under 5, along with Thailand. These health issues in early childhood have significant negative long-term implications for an individual’s life chances and the human development of the countries.

Family changes in Southeast Asia reveal some limitations in major theoretical frameworks of global family changes that are based largely on Western experiences and assume unilinear evolution. More attention is needed in these frameworks to the unique kinship system, religion and culture norms, and the influence of public policies that also played very important roles in explaining the family diversity in this region. Rapid socioeconomic changes in this region are expected to happen in the next few decades. The family demographic and cultural contexts will shape the future development in Southeast Asia. As the economic and geopolitical influence of this region increases over time, understanding the historical trends and patterns will help one to anticipate future opportunities and challenges in development in this region.