The level of Australia's population has become an issue of
debate over recent years. This debate has included issues of total
population size, immigration and ageing. Knowledge of the
population at any time is vital in resolving these debates and in
subsequent government planning decisions.
Population is also used on a routine basis for such
administrative purposes as the determination of electoral
representation and the allocation of Australian government funding
among the States.
There are two main measures of population. One of these is the
census measure, the other is an estimate called the estimated
resident population.
Census
Every five years the Australian Bureau of Statistics (ABS)
conducts a census of the population of Australia. One of the
results of this process is a total enumeration of the population of
Australia. The census includes all people in Australia at the time
of the census with a few minor exceptions. The census provides the
benchmark measure of Australia's population and the measure on
which estimates are made in the period between censuses.
Population estimates
Between censuses the ABS makes quarterly estimates of
Australia's population based on the census figures with allowances
made for overseas visitors and Australian residents temporarily
overseas at the time of the census and for a number of other
statistical reasons. These estimates are made using data on natural
increase and overseas migration. The most usually quoted figures
for Australia's population come from these estimates.
Natural increase
Natural increase is defined as the number of live births less
the number of deaths.
Natural increase has been the major source of growth in
Australia's population in recent years. Figure 1 shows Australia's
natural increase in the period since September 1971.

Overseas migration
Overseas migration is made up of two components-overseas
arrivals and overseas departures. The only migration movements
counted in the process of population estimation are permanent and
long-term arrivals and departures. Short-term movements-those of
twelve months or less-are excluded. Net estimated overseas
migration is the result of subtracting departures from arrivals.
Allowance is made in these estimates for people who 'jump'
categories from short to long-term and vice versa.
The migration component of population growth is more volatile
than natural increase because it is directly caused by government
immigration policies which are responsive to political, social and
economic conditions in Australia and in the rest of the world.
Figure 2 shows Australia's net overseas migration in the period
since September 1971.

Estimated resident population
The estimated resident population of Australia is the population
obtained by adding to the estimated resident population at the
start of a period natural increase and net overseas migration.
MESI Table 7.1
Monthly Economic and Social Indicators Table 7.1 shows:
- quarterly data on natural increase, net overseas
migration and resident population;
- annual totals for natural increase and net overseas
migration; and
- mean-average-annual population.
Monthly data on natural increase and net overseas migration are
graphed to show the movement in the series over the past few
years.
Further information can be obtained by contacting a member of
the Statistics Group, Information and Research Services, Department
of the Parliamentary Library.
This feature was prepared by Greg Baker.
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