A Country's Age Mix Predicts How Much It Can Produce

If you want to predict how much a country can produce, look at how old its people are. Age alone turns out to be remarkably good at predicting what a person will add to the national economy.

Demographers show it with a chart called a population pyramid, which sorts residents by age. The wider the bar for each age, the bigger that cohort's portion of the total. Spending and saving track the life cycle in every society, which is why the mix matters.

There are four broad groups. Seniors live off savings, so they spend cautiously, avoid risk, and draw the least attention from sellers. Then come the producers, people in their thirties and forties at peak earning power, directing income toward investments, retirement accounts, and costly trips. They also carry weight well beyond their numbers in discovery and business. Landmark breakthroughs tend to come from people in that span, and the average age of top startup founders is 45. Because this group exerts influence well beyond its headcount, even a modest change in its size spreads widely.

After them come younger adults, students and recent graduates who drive demand for loans. Finally there are infants, who cost money for decades before they return economic value.

The balance among these groups matters a great deal. If almost everyone were an infant, society would face a scramble for child care, constant wailing, and little work getting done. If almost everyone were 30 to 60, output per person would soar for a time, with few young or old to support. Two decades later, though, that bulge would reach retirement together, leaving too few earners to fund pensions and risking broad social breakdown.

Culture, politics, and geography still matter. Think of governing and other conditions as additional ingredients that must combine with age structure to produce a working result. A country still needs effective institutions and other strengths to turn a favorable age mix into lasting prosperity.