More than 50 countries worldwide face the risk of a pension crisis as the number of people over the age of 65 is set to exceed that of the young by 2030.
New independent research by Joseph Chamie suggests by 2030 there will be a total of 56 countries who have more old people than young - 26 additional countries from the present.
New Zealand is also among the 56 countries, as is Britain, the United States, Australian, Thailand, Cuba and Albania - just a few countries anticipating a crisis.
As of June last year the ageing population of New Zealand had nearly doubled in 2013 since 1981, according to Statistics NZ.
The 2013 Census recorded 607,032 residents aged 65 years and older, forecasting that number to more than double again by 2038 to 1,285,800.
As the proportion of people aged 65 and over increases, the number of younger people falls.
The proportion of people under the age of 15 was recorded at 26.9 per cent in 1981 and 20.4 per cent in 2013, with further decreases forecast.
In 1995 Italy was the first country to reach the milestone of more old than young, followed shortly by Japan, Germany and Spain.
It was estimated that in Italy in the 1950's there were 10 people of working age to each retiree - today there are only three per pensioner.
An ageing population is said to be one of the main reasons European countries such as Italy and Germany are actively welcoming working-age migrants.
Last year France, Canada, Croatia, Denmark, Poland, Romania, Serbia, Netherlands, Malta and Bosnia-Herzegovina joined the list of countries with more old than young.
China's one-child policy amendment was lifted last year amid fears of an ageing population and Japan has been heavily investing in technology and the development of robots to help with care of the elderly.