Decision Value & Value-of-Information (VoI) Calculator
An interactive worksheet that captures action payoffs, state probabilities, analysis costs, and simple analysis-outcome scenarios. Saves your inputs and guides you through computing expected value and the value of information (VoI). Supports both a quick estimate and a two-outcome detailed VoI calculation.
Decision Value & Value-of-Information (VoI) Calculator
Purpose
Use this calculator to focus analytic effort where it will change decisions. Enter payoffs for two alternative actions under two possible states of the world, your current probability estimate, and the estimated cost of an analysis. Two calculation modes are supported: a quick estimate where you provide an estimated expected value after analysis, and a detailed two-outcome scenario where you provide likely analysis outcomes and their probabilities.
Key formulas (manual)
- Expected value (EV) of an action = P(state1) * payoff_if_state1 + (1 - P(state1)) * payoff_if_state2
- Current decision EV = max(EV(action A), EV(action B))
- Value of Information (VoI), quick estimate = Estimated EV after analysis - Current decision EV - Cost of analysis
- Value of (sample) information, detailed = Sum_over_outcomes[P(outcome_i) * EV(best action if outcome_i)] - Current decision EV - Cost of analysis
How to use this form
- Enter payoffs and your current probability to compute the current decision EV (shown in the example below).
- Use the quick estimate if you have a solid estimate of the expected improvement an analysis would produce (enter it as “Estimated EV after analysis”).
- Use the detailed two-outcome mode if you can think of two likely analysis outcomes (for example, the test says “high demand” or “low demand”), estimate their probabilities and the EV you would get under each outcome.
- If VoI >= cost of analysis (and the result justifies implementation effort and timing), prioritize the analysis; otherwise deprioritize.
Example
Marketing reallocation example (simplified): Action A = keep current spend, Action B = reallocate 20% to channel X. Two states: High response or Low response. Suppose you estimate P(High)=0.4. Action A EV = 0.4*100 + 0.6*80 = 88. Action B EV = 0.4*140 + 0.6*50 = 86. Current decision EV = max(88,86)=88 (choose A).
Quick estimate: you estimate analysis would let you achieve EV=95 on average; cost_of_analysis=3 → VoI = 95 - 88 - 3 = 4 (positive, so analysis is worthwhile).
Save a personal copy, bring it to your team, or tailor the questions and workflow to fit what you are hungry to improve.
Discussion
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