Budget Simulator vs Spreadsheet: Which Teaches More?

Two tools, one arithmetic

Both a budget simulator and a spreadsheet start from the same equation: revenue minus spending equals the balance. Both express that balance as a share of GDP, because a deficit of €168bn means something different in an economy of €3 trillion than in an economy of €300bn. Both are only as good as the numbers you put in.

Where they diverge is in what they make easy. A spreadsheet makes calculation easy. A simulator makes consequence easy. Confusing the two is why so many earnest budget exercises end with a neat table and no understanding.

There is also a difference in what each tool assumes about the person using it. A spreadsheet assumes a competent analyst who needs speed, control and an audit trail. A simulator assumes a curious non-expert who needs the constraints to be visible and the feedback to arrive fast enough to change the next decision. Both assumptions are reasonable; they are simply assumptions about different people, and the tools fail when you use one for the other’s job.

What a spreadsheet does better

Spreadsheets are the professional tool, and there is no reason to pretend otherwise. When the goal is a defensible number rather than a lesson, the spreadsheet wins on almost every dimension.

• Precision: you can model a measure to the last euro and show your work line by line.
• Audit trail: every change is traceable, which is what accountability requires.
• Flexibility: any structure, any scenario, any assumption you can name.
• Versioning: you can keep February’s plan next to November’s revision and explain the difference.
• Scale: a spreadsheet handles a full ten-year path and a debt trajectory without straining.

What a budget simulator does better

A simulator gives up precision and buys something a spreadsheet cannot sell: the experience of living with a decision. That turns out to be the part most people lack.

• Consequences: you feel the popularity cost of a cut rather than reading a note about it.
• Pacing: decisions arrive monthly, and so does the pressure. You cannot optimise for a year in one sitting.
• Trade-offs: the political cost of a measure is explicit, not an annotation in column H.
• Mistakes: losing a season teaches faster than a red cell in a spreadsheet ever will.
• Motivation: it is far easier to get a student, or a colleague, to play twelve episodes than to audit twelve tabs.

Where the numbers come from in both

Neither tool generates its own facts. Serious budget work starts from official statistics: national accounts and deficit figures from INSEE in France, harmonised government finance data from Eurostat across the EU, and the Congressional Budget Office’s projections in the United States. The European Commission’s forecasts supply the growth assumptions that everything else depends on.

A good simulator is transparent about this. It does not claim to forecast; it calibrates its starting position to real published figures and then models the relationships that matter for play — growth affects revenue, interest rates affect the cost of debt, and public opinion affects how much resistance a measure meets.

That is the honest division of labour. The spreadsheet is where you would do the real forecast. The simulator is where you find out why forecasts are hard.

Feedback: the thing a spreadsheet cannot fake

In a spreadsheet, you change a cell and the total changes. That is a calculation, not a consequence. Nothing pushes back. Nobody loses an election.

In a simulator, a decision is followed by reactions. Ministers resist, the press frames the measure, the bond market reprices your credibility and popularity moves — sometimes immediately, sometimes with a lag that makes the original decision look safe in hindsight. Learning to read those reactions is the skill that transfers back to the real world, because real finance ministries spend most of their time managing reactions rather than choosing numbers.

This is also why a simulator exposes the difference between the deficit and the debt. Players who cut the deficit to 2.9% and watch the debt ratio keep climbing learn something that a static table rarely makes vivid: a stock can grow while the flow is shrinking.

The practical consequence is that a simulator is better at revealing what you do not know. A spreadsheet cannot tell you that your package is politically implausible, because political plausibility is not a cell. A simulator can, by letting you watch the same measure become more expensive as the year goes on and the objections organise.

Using both, in the right order

The most effective classroom sequence uses a simulator first and a spreadsheet second. Students play a season, take a position, and then have to justify it in a model where every assumption is visible.

The reverse order works less well. Given a spreadsheet first, students treat the exercise as arithmetic and never develop a view. Given a simulator first, they arrive at the spreadsheet with a question they actually want to answer.

For professional training the same logic holds. A thirty-minute simulation is a cheap way to make a room of adults feel the constraint before you show them the long-term debt path and the interest-cost arithmetic that follows from it.

A useful exercise for a class or a training room: play one season, write down the deficit, debt ratio and popularity you achieved, then open a spreadsheet and try to reproduce the same plan with explicit assumptions. The gap between the two — the parts you could not formalise — is the most interesting output of the session, and it is usually larger than anyone expects.

How to judge any budget simulator in five minutes

Six questions separate a serious simulator from a calculator with a colour scheme.

• Check the starting position against published data; if it is invented, stop there.
• Look for the debt ratio, not just the deficit. A simulator without a stock variable is teaching half the problem.
• See whether measures carry both a financial cost and a political cost. One without the other is a calculator.
• Play two months and ask yourself whether anything you did made a future decision harder. If not, the trade-offs are decorative.
• Check the sources page. A simulator that cites INSEE, Eurostat, the OECD or the CBO is at least trying to be honest about its foundations.
• Ignore claims about being educational. Ask what a learner can do afterwards that they could not do before.

Where ours fits

Our simulator is deliberately at the teaching end of the spectrum. It runs in a browser, it is free, it has twelve episodes and five indicators, and it calibrates its starting position to the real French situation rather than to an invented country.

It is not a forecasting tool and it does not pretend to be one. If you want to build a five-year debt path with your own assumptions, use a spreadsheet — and we would say the same in any lesson plan. If you want to understand why the people who build those spreadsheets have such difficult jobs, play a season first.

Both tools are free in the sense that matters here. You already have a spreadsheet. The simulator is in the navigation bar.

The honest summary is that both tools are cheap and neither is a substitute for judgement. A simulator gives you a position and a feel for the constraint; a spreadsheet lets you test whether that position survives contact with real numbers. Anyone who wants to understand fiscal policy should be able to do both, and almost everyone starts with the one that is fun.