Recently, I came across some videos on X and TikTok about anti-government protests in Indonesia and Nepal. I noticed that although the demonstrations in these two countries had different triggers, they shared one thing in common: young people played a significant role. The protests in Indonesia in August 2025 were initiated primarily by university student alliances. Meanwhile, the demonstrations in Nepal were simply dubbed "Gen Z protests," where elements from the Japanese anime One Piece were seen on multiple occasions.
This phenomenon reminded me of a rather influential concept in political science, sociology, and demography: the Youth Bulge Theory. The core idea is that when the proportion of young people aged 15 to 29 is excessively high in a country's population, the risk of social unrest, conflict, and even revolution increases significantly. The reasons behind this can include economic pressure and unemployment, political alienation and a gap between expectations and reality, competition for social resources, and a strong capacity for mobilization.
So, I decided to look up the population and demographic data for Indonesia and Nepal in The World Factbook. Based on their population structures and median ages, both are "young" countries.
Indonesia
Median age: 31.5 years
Nepal
Median age: 27.6 years
These two cases are an excellent testament to the fact that population and demographic data are crucial, even indispensable, for analyzing political and social issues.
In Nepal, with a median age of 27.6, we see a structural and almost inevitable dilemma. The protests are not an isolated political event but the necessary consequence of a nation unable to support its overwhelmingly young population structure. Demographic data reveals the root of this social movement as a "chronic illness."
In Indonesia, with a median age of 31.5, we can understand why a seemingly ordinary economic policy (cutting subsidies) could trigger such a massive social tremor. The policy struck a direct blow to the largest and most easily mobilized group in society: young adults. Demographic data explains the "detonator" and the source of energy for this social movement.
A country's demographic structure is its "hardware" or its "underlying operating system." Politics, the economy, and culture are the "software" or "applications" that run on this hardware. The specifications of the hardware—whether the population is young or old, large or small—fundamentally determine how the software can run. For a country with a median age nearing 50 (like Japan), social issues will inevitably revolve around pensions, healthcare, and labor shortages. For a country with a median age in the 20s, the core conflicts will necessarily be about employment, education, and identity.
Demographic data is the most predictive of all social science data. The size of a country's labor force in 20 years, or the pressure on its pension system in 30 years, is largely determined by the demographic structure of today—because the people of the future have already been born.
This reminds me of a time in 2022 when I used a population data sample I had come across to forecast the trend of China's real estate market.
In July 2022, what may have been the most severe data leak in China's history occurred, with a database containing nearly one billion entries being sold online. The seller provided a free sample of about 240,000 entries to prove its authenticity. After obtaining this sample, I first validated the data. I visualized the address information and found its distribution largely conformed to the Heihe–Tengchong Line, which suggested the sample was reasonably random. On this basis, I then visualized the birth year information. As I stared at this population pyramid, I noticed a phenomenon: a clear peak between 1986 and 1990, followed by a rapid decline. The number of births in 2002 was less than half of that in 1990.
At that time, real estate companies like Evergrande were entering a crisis, which inspired me to use this data to analyze and predict the market's trajectory. My core deductive logic was:
Peak Birth Cohort + Average First-Time Homebuyer Age = Peak Homebuying Demand Window
Combining this with the average first-time homebuyer age of around 30, as later mentioned in the Beike Research Institute's "2023 Homebuyer Survey Report," I concluded that the peak demand driven by first-time homebuyers in China's real estate market should have occurred between 2016 and 2020. After that, as the much smaller subsequent birth cohorts (born in 1991 and later) reached the age of 30, the demand side of the market was set for a structural shift into a downward trajectory.
Looking back from today's vantage point in 2025, the historic turning point for China's real estate market is widely considered to have been in 2021. Starting that year, as numerous major property developers faced debt crises (like Evergrande), national sales of commercial housing, both in area and value, began to show negative growth, a trend from which it has never recovered. From 2022 to the present, the entire market has entered a profound, structural downturn, characterized by falling prices, shrinking transaction volumes, and low market confidence.
From protests on the streets of Jakarta and Kathmandu to the boom and bust of China's real estate market, these disparate events share a common driver: population dynamics. These cases demonstrate that slow-moving demographic shifts fundamentally shape the trajectory of a society's economy and politics. The visible tides of social movements and market forces are, in essence, reflections of underlying generational change. To understand population is to grasp one of the most powerful, yet often overlooked, forces of our time.