As a result of declining fertility, and rising longevity, the median age of the world's population is increasing by about three months each year.1 In Australia, whereas today there are about five people of 'working age' for every person over 65 years, by mid century there will be just over two, according to ABS population projections.2 Assuming all other things unchanged, that implies a substantial impact on the rate of growth of per capita national income, and on the proportion of national income required to sustain the non-working part of the population.
That, in turn, would raise thorny issues of income distribution and require careful management of the policies which affect that distribution. Whether such an assumption – that all other things remain unchanged – should be made is another thing altogether.