The largest, most transformative demographic shift the world has ever experienced has now fully taken hold. We are in a period of dramatic change where there are more people over 60 than under 14 globally, dependency ratios are creeping over 50% throughout the world, and age-related entitlement spending is bankrupting public and private economies.

Until recently, population ageing was limited to Europe, US, Japan, Australia and a few other countries. Today, however, emerging nations are facing similar challenges. Therefore, the response must be truly global. In China, Brazil, India, Turkey and elsewhere, lifespans have nearly doubled in the past half century, nearly equalling those in high-income nations. And birth rates have fallen just as precipitously.

Despite the massive historical change, we continue to build careers, deliver healthcare, educate citizens and manage public finances based on 20th century demographic arithmetic. With 2 billion over the age of 60 very soon and with the lowest-ever recorded birth rates, new thinking and action are required.

We must begin the process of re-inventing social and economic institutions that make sense for 21st century demography. Economic growth, development and wealth creation hang in the balance, but real changes must also take place on the ground in the communities where we live. As lives routinely stretch into the 90s, education must broaden its scope beyond the young and re-assess its purpose. Workplaces must become “age-friendly” to position adults to contribute later into life.

How can local, national and global economies grow if retirement ages established in the 19th century by Otto Von Bismarck continue to govern working lives? Retiring in the 60s is both undesirable and unfeasible for 21st century longevity.

Age-related entitlements must evolve. Throughout the world ­- from Japan and Greece to California – public finances have been through crises because they are built upon 20th century demographic projections. No single economic factor is threatening global public economic health more than the incompatibility between last century’s social welfare entitlement systems and this century’s demographics.

Medical innovation and health delivery must respond to ageing populations – both the “old” today and the “young” who are preparing for longer lives. What are the possibilities for adult immunization? What are the potential cures for Alzheimer’s, a disease that already consumes 1% of global GDP? What technologies and medicines can enable an active, productive ageing by mitigating vision, mobility and dermatological deterioration?

New care models that provide more efficient and effective outcomes targeting patient are needed. And, urban planning must respond to the changing needs of the population and aspire to become what the World Health Organization calls age-friendly cities.

At Davos last year, the World Economic Forum launched Global Population Ageing: Peril or Promise. The metaphor is precisely correct. Two billion global citizens over 60 can be a burden to economic growth and development. Or, if we make the structural changes aligned to 21st century demographic realities that enable an active and productive ageing, these older adults will become the greatest success story of our time.

 Author: Michael W. Hodin, Ph.D. is Executive Director of Global Coalition an Ageing and member of the Global Agenda Council on Ageing

 Image: An elderly man sits on a bench in central Pontevedra, Spain REUTERS/Miguel Vidal