Make a decision with imperfect information

H2 Economics - syllabus 9570, 2026

Original teaching notes

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Expected profits depend on uncertain demand and cost information.

A firm may want to maximise profit but lack reliable demand, cost or competitor information. Forecasts are not guaranteed outcomes. An output chosen from estimates can be reasonable when made yet cease to be best when conditions change. Identify the uncertain input that could reverse the ranking, the cost of gathering information and any constraint on experimentation. A specific review condition is more useful than simply saying that the outcome depends on circumstances.

Information
A forecast is an estimate of what may happen. A firm can aim for maximum profit while having incomplete information about demand, costs or competitors.
Recommendation
A recommendation is conditional when it says what would change the decision. If extra revenue falls below the plan's extra cost, a previously profitable expansion can become unattractive.
Review
Bookings, trial sales or updated cost quotes can change the ranking of options. Gathering that evidence also costs time or money, so compare its value with its cost.

Apply the distinction

Information cost

Gathering more data or running a trial also uses resources; its value depends on how it can improve the choice.

Worked example: Should the repair shop open later?

A repair firm forecasts $400 extra weekly revenue from later opening and $300 extra relevant cost. It is unsure whether another shop will also stay open; the competitor response could reduce the extra revenue to $240. No other benefit or cost changes.

  1. With the original forecast, the extra profit is 400 - 300 = $100.
  2. If the competitor response reduces extra revenue to $240, the same plan changes profit by -$60.
  3. The preferred choice is sensitive to demand, not settled by the original revenue forecast. Observe trial bookings or gather evidence about competing opening hours.
  4. A limited trial may be useful if its information benefit exceeds its cost. Set a review condition: continue only if the expected relevant revenue exceeds the additional cost, allowing for uncertainty.

Watch out for this

A firm that wants maximum profit must know the exact best output.

An objective and the information needed to achieve it are separate. Estimates and subsequent review matter.

Check your understanding

An expansion is forecast to add revenue $120 and cost $100. Which new evidence would reverse its financial case under unchanged assumptions?

  1. Extra revenue is now expected to be only $80.
  2. The firm has many customers.
  3. Revenue remains $120 and cost falls to $90.

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