Rather than delve into issue opinion polling, or assess presidential campaign strategies, political demographers assume that political change is the predictable product of a set of mutually reinforcing social, economic, and demographic transitions, which can be tracked using data. But is this true in a country like the United States that has been in the advanced stages of these development transitions for decades? If these transitions are as important as demographers believe, could their variation among the 50 states explain the outcome of the recent U.S. presidential election? If so, what could they tell us about America’s electoral future?

Until several months ago, demographers regarded a youthful age structure as an unequivocally detrimental demographic characteristic. Where more than half of the population is younger than age 25, countries are unable to attain high levels of economic and human capital development and face an increased risk of some forms of civil conflict. Yet, so far, during the ongoing pre-vaccine stage of the COVID-19 pandemic, the most age-structurally mature countries have been hardest hit by the disease. These countries are generally urbanized, wealthy, well-educated, and include a large proportion of seniors. And, somewhat surprisingly—despite being equipped with advanced medical technologies—these countries are experiencing the highest rates of mortality from complications related to COVID-19.

The Western Sahel region—a cluster of arid, low-income countries stretching from Senegal, on Africa’s Atlantic coast, inland to Mauritania, Burkina Faso, Mali, Niger, and Chad—is home to the world’s most youthful populations. According to current UN Population Division estimates, about 57 percent of this six-country region’s population is 19 years old or younger. As security conditions deteriorate across the rural Sahel, governments in Europe and North Africa are taking notice of these countries’ demographic status—and for good reasons. Sustained population youthfulness (often called a “youth bulge”) contributes to low levels of educational attainment, joblessness and social immobility, and ultimately to rapid population growth, which tends to drive declines in per-capita availability of freshwater and other critical natural resources: factors that are associated with the risk of persistent violent conflict and represent powerful push factors for migration.

This year, 2018, marks the 60^th anniversary of a landmark publication by a pair of academic social scientists who first recognized the close relationship between population age structure (the distribution of a country’s population, by age) and development. In Population Growth and Development in Low Income Countries (Princeton U. Press, 1958), demographer Ansley Coale (1917-2002) and economist Edgar M. Hoover (1907-1992) theorized that eventual declines in fertility would transform developing-country age structures. Coale and Hoover demonstrated that these newly transformed age structures would exhibit larger shares of citizens in the working ages, and smaller shares of dependent children and seniors (Fig. 1). This transition, they argued, would someday help lift countries with youthful populations in Asia, Latin America, and Africa out of the low-income bracket.

While the World Population Prospects—the UN Population Division’s demographic estimates and projections—will never land on anyone’s non-fiction best-seller list, the latest version holds some noteworthy true stories. And the most remarkable demographic story of all may be Bangladesh’s.

The Kurdish people’s century-long quest for self-determination reveals a key aspect of ethnic separatist conflicts. Ideas of nationhood can endure for generations, unifying people across borders and often making separatist conflicts hard to resolve. But how much harder is it to resolve separatist conflicts than other violent, non-territorial intra-state wars (such as political revolutions)? In practical terms, how much longer, on average, can policymakers expect separatist conflicts to persist and reoccur than the typical political revolution? These are tough questions. Surprisingly, demography helps us find the answers.

After four months of political unrest and more than 250 deaths, the calls for Nicaragua’s embattled president Daniel Ortega to step down are escalating. One of political demography’s most robust statistical findings tells us that countries where an authoritarian government rules a youthful population, any change in regime typically yields an autocracy or at best, a partial democracy. Only very rarely has a liberal democracy emerged immediately after a rebellion in a youthful country (one with a population with a median age under 26 years). Given this, if Ortega is ousted from office, what type of leader should foreign affairs analysts expect to replace him?