A population reservoir absolutely could not be built within one's own country. Generally speaking, population reservoirs were cities and villages.
For example, cities continuously absorbed young and middle-aged laborers from the countryside, thereby gaining an endless supply of workers for low-end industries and driving their continued development and prosperity. Under normal circumstances, cities themselves had low natural population growth rates, and once development reached a certain stage, they would most likely experience negative growth without an influx of outside population.
Population aging and the decline of low-end industries were fatal to urban development, and the same was true for nations. Of course, low-end industries were dynamic. Technology advanced with time, and original industries would become low-end industries.
Naturally, the solutions were simple enough: introduce outside populations, or truly achieve machines replacing human labor. However, Ernst, a man from the twenty-first century, knew that even another century later, machines still could not replace human labor. If machines truly replaced human labor, then the world would probably have achieved Great Harmony as well. Such a utopian society was pessimistically estimated to be impossible even after several more centuries—perhaps humanity would never achieve it at all.
Therefore, when formulating East Africa's national policies, Ernst often used the social problems of the twenty-first century as references, doing his utmost to delay similar problems from emerging in East Africa's future.
Take population issues, for instance. If East Africa could become a developed country in the future, it would naturally face labor shortages. At that time, East Africa would most likely introduce foreign populations, or stubbornly hold on like Russia, causing its population to decline continuously and economic development to stagnate.
Or it could be like Europe and bring in refugees. Yet refugees were a double-edged sword, capable of having an immense impact on European culture,