Tasmania’s population is ageing at an accelerating rate. It’s a population on the cusp of decline. In fact, it's the only state projected by the Australian Bureau of Statistics to enter into population decline during the projection period 2012 to 2101.
Yet the incoming Liberal Government has set a growth target of 650,000 by 2050. While not an unreasonable target, averaging an annual growth rate of 0.6 per cent (equivalent to the average over the last 10 years), it may not be realistic. As a state, Tasmania is currently in a position in which the population age structure is no longer conducive to natural growth. Let me explain.
The capacity for population growth for any region is derived from a population’s age structure. The makeup of Tasmania’s population, like any other population, is influenced by what demographers refer to as the components of population change and their complex interaction.
These are natural increase (the difference between births and deaths), net overseas migration to Australia and in sub-national populations such as Tasmania’s, interstate migration. Furthermore, the two correlates for population growth are the size of the reproductive cohort (women aged 15 to 49 years) and economic performance.
It is Tasmania’s rate of population ageing, and its causes, which will detrimentally impact on the State's ability to grow its population. In Tasmania, the population is predominantly ageing structurally (the proportion of older people is increasing) rather than numerically (the number of older people is increasing), as is the national aggregate. Structural ageing eventually leads to more deaths than births (natural decline) which is caused by the accelerating net loss of young interstate migrants and net gain of older interstate migrants — the youth are leaving Tasmania for the mainland, a phenomenon increasingly being referred to as the Tasmanian Diaspora.
The net loss of young interstate migrants effectively removes young adults and their future children from the population and reduces the number of replacement children (the positive component of natural increase). Older interstate migrants moving to the state adds to both the number and proportion of the elderly and brings forward the point of population decline.
Tasmania's Total Fertility Rate (TFR) is hovering around the population replacement rate of 2.1 births (the replacement rate is considered to be the desired TFR as it provides the number of births required to replace the population and achieve a stable population age structure — in the absence of migration).
A high TFR doesn’t automatically translate into a high number of children being born. This is because the TFR does not take into consideration the size of the reproductive cohort. The number of children being born in Tasmania (and any other region) is dependent on the number of women of child bearing age — not the fertility rate.
In Tasmania, the size of the reproductive cohort has been declining both numerically and structurally since the largest cohort was born in the early 1970s, thanks initially to below-replacement-level fertility rates and also to net interstate migration losses of young adults.
Historically, net interstate migration of young adults was offset by natural increase, due to the size of the reproductive cohort, but this is not the case any more. Essentially this means that Tasmania is experiencing a more rapid process of structural ageing than Tasmania’s high fertility rate suggests.
Much reliance is placed on a return to positive economic performance of the state to reinvigorate population growth. However, there are two misconceptions associated with the supposed correlation between economic growth and population growth.
The first misconception is that the population growth rate will increase if the State has a strong economy. However, it is relative performance that matters; an increase in population growth will only occur if the state is outperforming the Australian economy. Increasing opportunities outside Tasmania will continue to attract young adults to leave the state.
The second misconception is that while the state may experience population growth in the short term as a result of positive economic performance, the age profile of interstate migration movements will actually age the population at an even faster rate. It will bring forward the point at which the population enters into decline. Essentially, the age profile of any net migration gains is paradoxically generating an internal momentum of decline within Tasmania’s age structure.
Also important is that the sources of population growth differ between Tasmania and Australia. While Australia generates around 40 per cent of its growth from natural increase, 60 per cent of its growth comes from overseas migration. In Tasmania, any growth from overseas migration is offset by losses in interstate migration — and therefore any net growth is sourced from natural increase, which we know is declining due to structural ageing.
As such, the gap between Tasmania and Australia for both the rate of population growth and the rate of ageing is widening, much like many other regions in Australia.
The reality of the components of population change in Tasmania presents both challenges and opportunities for policy makers. However, policy solutions at a national level may not be appropriate at a regional level like Tasmania and may in fact exacerbate the population challenges at a sub-national level.
Tasmania’s unstable population age structure requires economic and social policy development to reflect the makeup of its population. As such, Tasmania has a number of greater challenges to address before it can consider a population target – although effectively addressing these challenges may result in the organic population growth required to achieve the target set by the Liberal State Government.