Demographics, as opposed to geography, economics or technology, is a relatively understudied aspect of international politics. This may be because beyond the obvious fact that population size matters, all other things equal, demographics do not matter very much. A list of “demographic hypotheses” follows:
First, as just mentioned, there is the brute fact of demographic size. As Stalin allegedly opined: quantity has a quality of its own. Demographic size matters in inter-state competition. Larger populations mean a larger economic output, larger military forces etc. Then again, the mighty and demographically weighty Inca empire was brought by a small, ragtag group of less than two hundred Spaniards (Diamond 1997). Meanwhile, Imperial Japan and Nazi Germany did not have sufficient man and hence economic power to prevail against the demographically and hence economically mightier powers like the Soviet Union and the United States. Nazi Germany came to close to defeating the USSR, and Imperial Germany did defeat the Russian empire militarily.
Second, youth bulges may prove politically destabilizing. Young adults may not find employment and channel their higher levels of aggression into political causes, increasing the chances of domestic civil strife and making it easier for political leaders to win popular support for an aggressive foreign policy, including military conflict.
Third, oldish, aging societies generate less rapid economic growth, leading a country to decline in terms of relative economic power. A growing share of economically inactive, old people puts downward pressure on savings and investment, in addition to limiting labor supply. An increasing consumption share and decreasing savings share may also lead to greater distributional conflict with a so-called grey majority opposing greater (non-consumptive) spending on a costly foreign policy, thereby limiting consumption. In such an environment, the “guns vs butter” trade-off will be even more acute, politically and economically.
Fourth, economically and psychologically, having fewer offspring may make parents more reluctant to see their government engage in high-risk foreign policies and armed conflict that puts their children’s (or child’s) life at risk. Like all the other hypotheses, this is an all-other-equal hypothesis. Intervening variables such as patriotism or conscription may limit the extent to which having fewer children impact a country’s inclination to go to war.
Firth, young people are often thought to be more innovative or more eager to embrace novel technologies. Google, WhatsApp and Facebook seem to suggest as much. Then again, these companies simply took advantage of basic research and marketized it. Fundamental technological breakthroughs, more often than not, are less driven by the propensity to adopt consumer-oriented technologies and more by costly basic research, often supported and financed by the state (Giddens 1985, Tilly 1992). To the extent that technological breakthroughs are related to inter-state competition, a country’s demographic profile may not matter all that much.