The Covid-19 pandemic, which shows no sign of abating, made 2020 a landmark year. But it was also a milestone year from a demographic perspective. From January to November 2020, there were some 39,900 births and 45,400 deaths in Hong Kong, a natural decrease of 5,500 people. Births fell sharply, by 17 per cent, while deaths rose by 4 per cent during the first 11 months of 2020 compared with the same period in 2019. It is very likely that the annual number of deaths will exceed that of births for the first time in Hong Kong’s history. It was the same story in Taiwan, with 147,702 births and 157,948 deaths. That’s 10,246 more deaths than births. In South Korea , there were 275,815 births, down 10.6 per cent from 2019, and 307,764 deaths, up 3.1 per cent from 2019. These demographic trends are likely to continue in these high-income Asian societies. When these “demographic time bombs” explode, economies, social welfare systems and health care systems will be hit hard, due to the decline in the number of economically active people and the increase in dependence ratios. Prolonged low fertility and rapid population ageing pose increasing challenges to these societies. Many governments have adopted a series of family policies to raise the fertility rate, such as extending parental leave , providing flexible working hours, and offering a baby bonus . However, the effect of these policies has been modest. Estimates continue to place the total fertility rate at less than one child per woman in 2020 in most high-income Asian societies. However, for a population to replace itself, this rate needs to be 2.1. Some argue that the current family policies do not really meet families’ needs. The 2017 Knowledge Attitude Survey by the Family Planning Association of Hong Kong suggested that the high cost of raising children was among the biggest obstacles to having children. Compared to the cost of raising a child, financial support from the government is meagre. Recently, we put forward a concept of “fertility elasticity”. Originally, elasticity is an economic concept. For example, price elasticity of demand refers to the percentage change in demand when there is a one per cent change in the price of a commodity. We applied the “elasticity” concept to fertility research to estimate the percentage change in the total fertility rate per the percentage change in the marriage rate or fertility rate of a specific group. We analysed the fertility elasticity of Hong Kong, Taiwan, Japan, South Korea and Singapore to find out which group of women were most influential in raising the total fertility rate. The results suggested that the fertility elasticity to the marriage rate of women aged 25-29 was the largest in all five societies. For every 1 per cent increase in the marriage rate of this group, the total fertility rate will increase by about 0.3 per cent in Hong Kong, Japan, Taiwan and Singapore, and about 0.24 per cent in South Korea. Japan’s Princess Mako’s wish to marry college boyfriend casts the spotlight on money If governments can remove the obstacles to marriage and raise the marriage rate, therefore, there would be a significant increase in total fertility rates. A challenge is that, at present, the mean age at first marriage is rising and the divorce rate is surging . The idea of the government intervening in people’s marriage behaviour remains controversial, as getting wed should be a personal choice. In addition, it is still uncertain whether births outside marriage will become socially accepted and widely practised in Asia, as happens in the West. The relative higher fertility rate in European countries is very closely related to the higher proportion of babies born outside marriage. For instance, in Sweden and France, the proportion is about 50-60 per cent. The governments of South Korea, Japan and Singapore have taken some action to promote marriage, such as providing dating consultation services and supporting cultural events that offer matchmaking. Love down to a science: is DNA matchmaking the ultimate dating tool? Singapore has a special housing scheme for courting couples while Japan’s government has tried to create more stable and permanent working positions for young adults. The Hong Kong government has devoted less effort to this. Indeed, the government should not and could not force those who do not want to get married to do so. But we can help remove barriers for those who want to tie the knot. Research tells us that fertility elasticity to third births, or higher, is very low. Thus, if family policies aim for people having three or more children, the impact on the total fertility rate may well be insignificant. Moreover, our findings indicate that, if family policies in Hong Kong, Taiwan and Singapore can encourage first births, and policies in South Korea can encourage second births, we may see a noticeable impact on the total fertility rate. A significant reversal in the fertility rate in these societies is unlikely without effective family policies. They should be a sustained, integrated and diverse policy portfolio which satisfies the different needs of families, creates a family-friendly working environment and targets the most influential groups. Meanwhile, an increase in productivity through automation and migration could also help mitigate the challenges arising from low fertility. Mengni Chen is a research scientist at the University of Cologne in Germany and University of Louvain in Belgium. Paul Yip is the chair professor (population health) in the Department of Social Work and Social Administration at the University of Hong Kong