Calculator Inputs
Formula Used
This calculator uses an open-economy income equilibrium model with taxes, transfers, imports, and demand shocks.
Disposable income: Yd = Y - T0 - tY + TR
Consumption: C = C0 + b(Y - T0 - tY + TR)
Imports: M = M0 + mY
Aggregate demand: AD = C + I + G + X - M + Shock
Equilibrium condition: Y = AD
Equilibrium income: Y = [C0 - bT0 + bTR + I + G + X - M0 + Shock] / [1 - b(1 - t) + m]
Multiplier: k = 1 / [1 - b(1 - t) + m]
How to Use This Calculator
- Enter autonomous consumption, investment, public spending, exports, and imports.
- Add behavioral rates, including MPC, income tax rate, and import tendency.
- Enter transfers, lump taxes, potential income, and target income.
- Use demand shock for extra spending, cuts, stimulus, or contraction.
- Press calculate to show results above the form.
- Download CSV for spreadsheet use.
- Use PDF export after calculation for a printable summary.
Example Data Table
| Scenario | C0 | MPC | I | G | X | M0 | Tax Rate | MPM |
|---|---|---|---|---|---|---|---|---|
| Base model | 500 | 0.75 | 350 | 450 | 240 | 120 | 0.12 | 0.10 |
| Higher imports | 500 | 0.75 | 350 | 450 | 240 | 120 | 0.12 | 0.18 |
| Stimulus case | 500 | 0.78 | 390 | 600 | 260 | 130 | 0.10 | 0.09 |
| Tighter policy | 480 | 0.70 | 310 | 390 | 230 | 125 | 0.18 | 0.12 |
Income Equilibrium and Balanced Systems
What the calculator measures
Equilibrium is a balance point. In physics, forces can balance. In income analysis, spending plans can balance output. This calculator uses that same balance idea. It finds the income level where planned spending equals total production.
Why the multiplier matters
The multiplier shows how strongly income reacts to a demand change. A high multiplier means a small spending shift can create a large output change. A low multiplier means leakages are stronger. Taxes, savings, and imports reduce the multiplier. They pull money away from repeated spending rounds.
Role of consumption
Consumption is driven by disposable income. The MPC controls this link. When households spend more from each extra income unit, aggregate demand becomes more responsive. This can raise equilibrium income. It can also make the model more sensitive to shocks.
Taxes, imports, and transfers
Taxes reduce disposable income. Transfers increase it. Imports reduce domestic demand because some spending leaves the local economy. The calculator includes all three items. This gives a fuller scenario than a simple closed model.
Using the output gap
The output gap compares equilibrium income with potential income. A negative gap may suggest weak demand. A positive gap may suggest pressure above normal capacity. The tool also estimates the shock needed to reach a target income. This can help compare stimulus, cuts, and trade changes.
Practical interpretation
The result should be read as a model estimate. It is not a forecast by itself. Real economies include prices, interest rates, capacity limits, confidence, and policy delays. Still, the calculator is useful for teaching, planning, and quick sensitivity testing.
Best use
Change one input at a time. Watch the chart and multiplier. Compare scenarios carefully. Keep rates realistic. Use the CSV and PDF options to save the results for reports, lessons, or further analysis.
FAQs
1. What is equilibrium level of income?
It is the income level where planned aggregate demand equals total output. At this point, the model has no unplanned inventory change.
2. Is this a physics calculator?
The topic is mainly economic, but it uses an equilibrium idea similar to balanced systems in physics. It finds a stable balance point.
3. What does MPC mean?
MPC means marginal propensity to consume. It shows how much extra income households spend instead of saving.
4. Why do imports reduce equilibrium income?
Imports are leakages from domestic spending. More import spending means less demand for local output, lowering the multiplier and income.
5. What is the spending multiplier?
The spending multiplier shows how much equilibrium income changes after a one-unit autonomous demand change, based on leakages and spending behavior.
6. What is a demand shock?
A demand shock is an extra positive or negative change in autonomous spending. It can represent stimulus, cuts, investment shifts, or export changes.
7. What does output gap mean?
The output gap is equilibrium income minus potential income. Negative values show weak demand. Positive values show income above potential.
8. Can I export the result?
Yes. Use the CSV button for spreadsheet output. After calculation, use the PDF button to save a printable summary.