Over the past three decades, economic and political demographers, using various measures, have discerned that increased age-structural maturity makes significant statistical contributions to levels of per capita income, to educational attainment, to declines in the frequency of onsets of intrastate conflict, and to the likelihood of achieving and maintaining liberal democracy. Some of the stronger statistical relationships have been used in forecasts. For example, using the United Nations Population Division (UNPD) demographic projections, political demographers have relied on the strong statistical association between age structure and stable liberal democracy to forecast the rise of democracy in North Africa more than two years in advance (in 2008)—at a time when regional experts believed that forecast to be absurd. Whereas critics remain skeptical of the murky causal connections of age-structural theory, its proponents counter that causality in the development of state capacity is complex and is less important than the theory’s positive qualities (namely, that it is forward-looking, its statistical findings are easily repeated, its forecasts have outcompeted regional experts, and its predictive products can be readily adapted to the needs of intelligence foresight, defense planning, and foreign policy analysis). Perhaps most important, the age-structural theory of state behavior has yielded a surprising number of “novel facts”—new knowledge concerning the observed pace and timing of state political, social, and economic behaviors.
Mark L. Haas
Most of the world has experienced a revolutionary and unprecedented development over the course of the last century and especially since the end of the Second World War: significant population aging. By any standard measure—median age, the number of 60- or 65-year-olds and over as a percentage of a population, or old-age dependency ratios (the ratio of seniors to working-age adults), most of the world is significantly older today than in the middle of the 20th century, and the trend is accelerating. The world’s great powers have not been immune to this trend. To the contrary, many of these countries have been leading the way, aging faster and to a greater extent than most other countries. By 2050, the median age of China, France, Germany, Japan, Russia, the United Kingdom, and the United States will be at least 40. Germany and Japan are currently two of the oldest countries in the world, and China is likely aging faster than any other country in history. How is the near worldwide phenomenon of population aging likely to affect international relations (IR)? Most scholars who have examined this issue have linked the potential effects created by aging to established IR theories. Most analyses that have developed around the issue of aging, in other words, have not created new theoretical approaches to the study of international politics. They have instead argued that aging is likely to affect key variables associated with existing IR theories, which will then tend to generate particular outcomes based on these theories’ predictions. The IR theories that studies of populating aging have most frequently tied into include ones from realist, diversionary war, and constructivist research programs. Many of the arguments that link the effects of aging to these theories reach opposite conclusions, with some predicting a much higher probability of international conflict due to aging, others the reverse. There are, however, very few empirical analyses that test these competing hypotheses, largely because aging is such a new phenomenon.