Reference scenario
RBA cash rate up from 3.85 to 4.50, simulated over two years. Run live on every page load - engine 1.0.0, 250 Monte Carlo draws.
Demo simulation - not an official forecast. The baseline economy is dimensionally correct and in the right neighbourhood of published Australian aggregates, but it is not an official extract. Every relationship is calibrated rather than estimated by this project. Results are scenario estimates, not predictions.
Prosperity Index
58.4
Broad-based material living standards
Modelled Wellbeing
58.5
Security and material proxies, not happiness
CPI
2.64%
from 2.70% at baseline
Unemployment rate
4.32%
from 4.20% at baseline
Prosperity Index
Broad-based material living standards at two years. A weighted composite whose weights are a value judgement, not a finding.
58.4
from 58.4 at baseline
Who the movement reached
- 826k households better off
- 4.9m households broadly unchanged
- 5.5m households worse off
The share of households the microsimulation puts on each side. It is shown beside the index rather than inside it, because averaging a gain across people who did not receive it is how a composite hides who paid for it.
What moved it - contributions sum exactly to 0.01 points
The right-hand column is each component’s weight. Contributions are exact rather than apportioned - the index aggregates its components with no lag, so these add up to the total by construction.
Headline indicators
Every variable the engine flags as headline, with its uncertainty band and confidence class. Each card opens its full derivation in the workspace.
Mortgage repayment
$4,461
House prices
$885k
Dwelling approvals
178k
Budget balance
-$29.9bn
Financial stress index
47.5
Cash rate
4.49%
Wellbeing
58.6
Mortgage rate
6.60%
GDP
$2.65tn
Disposable income
$1.71tn
Rents
$719
Consumer spending
$1.72tn
Unemployment rate
4.32%
CPI
2.64%
Wage growth
3.27%
Prosperity
58.4
Population
28.55m
Migration
260k
How it arrives
Scenario against baseline, with the P10 to P90 band from 250 Monte Carlo draws over coefficient uncertainty.
Average mortgage repayment
- Scenario
- Baseline path
House prices
- Scenario
- Baseline path
Rents
- Scenario
- Baseline path
Inflation
- Scenario
- Baseline path
Unemployment rate
- Scenario
- Baseline path
Real disposable income
- Scenario
- Baseline path
Who it lands on
A national average is the least informative view of a policy. These are the same result, disaggregated.
The whole population
Every modelled household on one bar, so the headline average is never read without knowing how many it reached.
- 7.4%826k households better off
- 43.6%4.9m households broadly unchanged
- 49.0%5.5m households worse off
Who gains and who pays
Change in monthly disposable cash by household group, at the reporting horizon.
By age
Monthly disposable cash by age bracket. Depth of colour is the size of the effect.
By state
A composite of housing, employment and construction exposure. Directional only - the model has no suburb-level detail.
When it lands
Effects do not arrive together. Each marker sits at the month that effect becomes material.
Scored across ten dimensions
Each dimension anchored so that unchanged is unchanged. The total is an average and is not plotted, because averaging a trade-off is how you lose it.
Policy scorecard
Movement from unchanged on each of ten dimensions. The total is an average and is deliberately not plotted - a policy that scores well by trading housing against employment is a different object from one that improves both.
What the engine says about it
Executive summary
Written by the deterministic narrator from the computed result - the same text with or without an API key.
Under the selected assumptions, RBA cash rate up from 3.85 to 4.50 produces the following over 2 years. Budget balance falls by $1.9bn; RBA cash rate rises by 0.64pp; Average outstanding mortgage rate rises by 0.55pp; Average mortgage repayment rises by 4.9%; House prices falls by 4.0%. On the household side, roughly 826k households end up better off in cash terms and 5.5m households worse off, with the remainder largely unaffected. The Modelled Wellbeing Index - a weighted composite of material and security proxies, not a measure of happiness - moves -0.68 points to 58.5.
In the first six months, RBA cash rate rises to +0.65pp; Average outstanding mortgage rate rises to +0.05pp; Average mortgage repayment rises to +0.10%. Then Financial stress index rises to +0.3 pts; First home buyer access falls to −0.2 pts; Investor demand falls to −0.09%. Then House prices falls to −0.18%; Price to income ratio falls to −0.18%; Inflation falls to −0.02pp. Transmission is fastest where a price is administered - interest rates, excise, subsidy rates - and slowest where behaviour has to change.
Between six months and two years, Budget balance falls to −$302.6m; Dwelling approvals falls to −0.70%; Job vacancies falls to −0.55%. Then Underemployment rate rises to +0.23pp; Unemployment rate rises to +0.12pp; Modelled Wellbeing Index falls to −0.6 pts.
The averages hide the distribution. recent buyers with large mortgages lose about $191 a month, while established mortgage holders lose about $152 a month. Meanwhile outright owners approaching retirement gain about $43 a month, and retirees with savings gain about $34 a month. That gap - not the aggregate - is usually what determines whether a policy survives contact with the public.
Two forces work against the headline result. Construction capacity loop: Trying to build more bids up the cost of building, which chokes off part of the increase. The reason a large approvals target delivers less than it promises. Housing supply loop: Higher prices induce building, which adds to the stock, which eventually lowers prices. The loop is real but extremely slow - the dwelling stock moves about 1.5% a year.
Start from a question
Pre-built scenarios covering the levers most often debated.
RBA raises rates 25bp
How far does one rate rise travel, and who feels it?
SimulateRBA raises rates 50bp
What does half a point cost mortgage holders, and what does it buy in inflation?
SimulateRBA cuts rates 25bp
Who gains from a cut, and what does it do to house prices?
SimulateMigration +100,000 a year
Does a larger intake make the economy bigger, or just the country more crowded?
SimulateMigration −100,000 a year
How much rental relief does a smaller intake actually buy, and at what cost?
SimulateBuild 100,000 extra homes
How long does building more take to reach rents - and does the construction sector have the capacity?
SimulateIncome tax cut
How much of a tax cut reaches spending, and how much reaches inflation?
SimulateMinimum wage +5%
What does a real wage floor increase do to prices and to employment?
SimulateIncrease JobSeeker 25%
What does raising the lowest incomes do to poverty, and what does it cost?
SimulateCombined housing package
Does attacking housing affordability from every side work better than any single lever?
SimulatePolicySandbox.ai provides scenario modelling and research tools. Results are estimates based on models, assumptions and available data, and should not be interpreted as guaranteed forecasts or as financial, legal, medical or government advice.