How often does the cohort miss its budget?
For a program director deciding whether next year's intake is safe to run: put in the offers you make, the share who usually accept, the fee and the costs, and get back the odds that too few students enroll and the odds the money falls short of budget. A cohort here is one intake of students who start together. The sample is a program with a twenty-four percent cushion over its minimum class that still misses its budget in 43 of every 100 years.
In plain words: a cohort is one intake of students who start the program together. This sheet turns your offers, your usual acceptance rate and your costs into two odds: that the intake is too small to run, and that it makes less money than the budget assumes.
Words on this sheet
- Cohort: One intake of students who start the program together. It is not a class in the timetable sense; it is the whole group admitted for this run of the program.
- Contribution: Fee income minus the costs of running the program. It is what the program hands back to the faculty after paying for itself.
School Intermediate Monte Carlo Pro engine
After you install, this is the model to open.
What If the Cohort Does Not Fill?
- In your spreadsheet, click the Sortia icon in the strip of icons down the right-hand edge. No strip? Click the arrow at the bottom-right to open it. You can also use Extensions, then Sortia, then Open Sortia.
- Click Start from a template and put that name in the search box.
- Pick the card with that name and click Load this template. It arrives on a new tab with real numbers already in it.
This one runs on a Pro engine, and every free install includes five full-quality runs on your own numbers, shared across all five Pro engines rather than five for each. After that, Pro is $199/year.
The answer
- Contribution, simulated
- $192,400 mean, against $203,600 on the sheet
- Under the faculty budget
- 41.9% of years land below $180,000
- Too few students to run
- 6.0% of intakes: once every seventeen
- A bad year
- $70,300 P5 contribution
One cohort, 160 offers out, and a take-up rate that has run between 32% and 61% over the last five years. That single range is where almost all of the risk lives, and it is worth saying why the model uses it rather than something more elaborate. You could treat each of the 160 offers as an independent coin flip, and the arithmetic of that gives a spread of about six students either side, which is small.
The year-to-year swing in the take-up rate itself is more than twice that, because it is driven by the market, the competition and the fee rather than by chance. So the rate is the input and the coin flips are noise inside it. Click Run on 20,000 trials. Contribution averages $192,428 against the $203,600 on the sheet, which makes the plan look honest.
Read the flags instead. The cohort falls below the 62-student viability floor in 6 of every 100 years, and is a conversation you will have in your career. And the third output, the one the panel offers to add, says the contribution falls short of the $180,000 the faculty budgeted in 43 of every 100 years (43.1%). The gap between those two numbers is the interesting part: the program is very unlikely to be cancelled and quite likely to disappoint, and those are different problems with different answers.
The percentile ladder makes the second one concrete. The P10 contribution is $93,250, less than half the plan figure, and the plan's own $203,600 sits at about the 54th percentile, so it is not a forecast, it is a slightly optimistic middle. Second run: raise offers from 160 to 190, leave everything else alone, and rerun. The floor is not breached once in 20,000 trials and the budget shortfall rate falls from 43.1% to 7.4%, because every extra student carries $8,250 of contribution and thirty more offers is about fourteen more students.
That is a real lever and a cheap one, which is the honest finding here even though it is not the dramatic one. Before you act on it, notice what the model does not know. It has no capacity ceiling, so it will happily enroll a hundred students into a room that seats seventy, and it assumes the take-up rate holds when the offer net is widened, which is exactly what a wider net tends not to do.
To adapt it, put your own offers, fee and floor in, and set the take-up range from your own five years of offer-to-enrollment data rather than from the target.
The model
It arrives on a tab called Template: What If the Cohort Does Not Fill:
| Offers made for the cohort (count) | 160 |
| Share of offers that enroll | 0.48 |
| Students enrolled (count) | 76.8 |
| Fee per student ($) | 9400 |
| Fee income ($) | 721,920 |
| Variable cost per student ($) | 1150 |
| Fixed cost of running the program ($) | 430000 |
| Contribution after all costs ($) | 203,600 |
| Smallest cohort that can run (students) | 62 |
| Cohort too small to run (1 = yes) | 0 |
| Contribution the faculty budgeted ($) | 180000 |
| Contribution falls short of the budget (1 = yes) | 0 |
Once it is in your sheet
- The model arrives with real numbers in it and runs as it stands, so you can press the button first and understand it second.
- Change the numbers to yours. The sheet marks which cells are inputs and which hold formulas, and most labels carry a note explaining the row.
- Press the run button at the bottom of the panel. It is labeled for the tool you are in, and the result lands on its own tab, with a written reading of it beside the figures.
Never used Google Sheets? Start here goes the whole way, in seven steps, and assumes nothing.
Next question
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- Three averages differ. Is that more than chance?Which Study Method Actually Works?
- Should you switch doors or stay?Switch or Stay? The Monty Hall Problem, Simulated
Every model like this one, and the method behind them: Monte Carlo simulation.