Data Commons, "World Fertility Rate: 1950-2023."⁸

1.The Economic Challenge

People are a labor force. The newborns are the future workers. With an aging population and a decline in fertility rates, the most alarming concern for states is the shrinking size of the labor force. Since labor is a critical factor in production and thus economic growth, a growing population also implies a growing economy in the context of more developed states, and vice versa. For example, in 1900, the total economic output of the U.S. was less than half that of Western Europe; however, since the U.S. population grew at a much faster rate than Western Europe’s, by the 2000s, the U.S.’s total output became 1.06 times that of Western Europe’s.² The linkage between population decline and economic stagnation often instills fear among policymakers.³ This then explains the current efforts made by multiple states to boost their own population growth.

However, the economic challenge not only affects the state as a whole and the policymakers who will lose seats due to economic stagnation, but also imposes higher economic burdens on individuals. With an aging population, individuals are expected to pay higher taxes to support the welfare structure and basic infrastructure.⁴

2.Military: who will serve?

An aging population with a declining population growth rate also raises questions about military recruitment. In most countries, the organization of the military relies heavily on the constant flow of young people who fill the junior positions in the personnel structure of the military.⁵ In the case of Germany, the aging population has resulted in 7,000 Bundeswehr vacancies remaining unfilled, particularly in the departments of information technology, medical services, aviation, etc.⁶ Persistent vacancies in military positions will eventually lead to the aging of the military, undermining its capabilities to ensure the security of the state. The effectiveness of the military is further compromised when considering the economic decline that a shrinking population often implies, as the domestic economy will no longer be able to support the often costly innovation and production of modern equipment.⁷

In the past few decades, the world has been seeing a trend of declining fertility rates, with the majority of states' fertility rates dropping below the replacement level of 2.1%. The tendency has changed from a “baby boom” to a “baby bust,” from high fertility and mortality rates to low fertility and low mortality rates.¹ WWhile a declining population growth yields multiple positive implications for the environment (e.g., increasing biodiversity, less waste, and potentially more land), it also creates pressing security concerns for states.