Model background
Migration works best when selection and capacity move together.
The simulator starts from a simple premise: migration can lift Australia's productive
capacity and public finances, but the same flow can create visible stress when housing,
recognition systems, and city infrastructure lag behind.
The benefit side
A well-selected permanent program can raise labour supply, fill specific skills gaps, add
tax revenue, and support export industries such as international education. Treasury's
intergenerational modelling is useful because it separates lifetime fiscal and GDP effects
by migrant stream rather than treating every arrival as identical.
The simulator therefore rewards higher skilled-primary shares and shorter skills
recognition lags. That does not imply family migration has no value; it means this first
model is trying to make the measurable economic channel explicit.
The pressure side
Population growth becomes politically and economically fragile when it outruns housing
delivery or concentrates heavily in already constrained cities. A national fiscal dividend
can coexist with renters facing a local supply shock.
The model translates NOM into an estimated dwelling requirement and compares that with an
annual homes-completed lever. It also treats student load, capital-city concentration, and
total volume as pressure signals.
Extreme settings
At low NOM and high building rates, the simulator tends to show capacity improving faster
than demand. At very high NOM, even a strong skills mix can be overwhelmed by housing and
city pressure unless construction also lifts.
These extremes are not predictions. They are stress tests that show which assumptions are
carrying the scenario.
What this is not
This is not a full macroeconomic model, a population forecast, or a moral ranking of visa
categories. It is a transparent first-pass policy simulator designed to expose trade-offs
and make the assumptions easy to challenge.
The next version should separate short-run and long-run effects more clearly, add richer
source notes, and allow alternative household-size, construction, and labour-market
assumptions.