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Ageing is a drag

But slower growth in older economies is more a choice than an inevitability

FOR THE first time in history, the Earth has more people over the age of 65 than under the age of five. In another two decades the ratio will be two-to-one, according to a recent analysis by Torsten Sløk of Deutsche Bank. The trend has economists worried about everything from soaring pension costs to “secular stagnation”—the chronically weak growth that comes from having too few investment opportunities to absorb available savings. The world’s greying is inevitable. But its negative effects on growth are not. If older societies grow more slowly, that may be because they prefer familiarity to dynamism.

Ageing slows growth in several ways. One is that there are fewer new workers to boost output. Workforces in some 40 countries are already shrinking because of demographic change. As the number of elderly people increases, governments may neglect growth-boosting public investment in education and infrastructure in favour of spending on pensions and health care. People in work, required to support ever more pensioners, must pay higher taxes. But the biggest hit to growth comes from weakening productivity. A study published in 2016, for example, examined economic performance across American states. It found that a rise of 10% in the share of a state’s population that is over 60 cuts the growth rate of output per person by roughly half a percentage point, with two-thirds of that decline due to weaker growth in productivity.

Why are older economies less productive? The answer is not, as one might suppose, that older workers are. Though some capabilities, notably physical ones, deteriorate with age, the…