Description
Calculate a supplied finite lottery expected payoff.
Behavioral economic tasks use explicit payoff units, reference values, time periods and supplied utility or discount conventions. A decision weight need not be a probability, one branch term is not a full expectation, and a nominal cost difference does not establish perceived switching difficulty or an actual preference.
Calculate a supplied finite lottery expected payoff.
When to use this tool
Use Lottery Expected Payoff when you already have probabilities, payoffs and need to calculate a supplied finite lottery expected payoff.
How to use the tool and how it works
- Enter probabilities, payoffs. Follow any array-alignment requirements below. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read expectedPayoff. Use the output convention below.
Require nonempty aligned probabilities/payoffs, probabilities in [0,1] and sum within 1e-12 of one; sum probability*payoff in input order.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| probabilities | Aligned nonempty weights in [0,1], summing within 1e-12 of one; not renormalized. | Required. Array of finite number; maximum items 256. |
| payoffs | Payoffs | Required. Array of finite number; maximum items 256. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| expectedPayoff | Expected Payoff | Required. Finite number. |
{
"input": {
"probabilities": [
0.25,
0.75
],
"payoffs": [
100,
0
]
},
"output": {
"expectedPayoff": 25
}
}Limitations and assumptions
- Weights within tolerance are not renormalized. Payoffs may be signed; expectation is not guaranteed payout, expected utility, risk preference or a random draw.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Review the full task design, incentive and payoff definitions, participant records and statistical analysis. Estimate behavioral models from appropriate data when local supplied-value arithmetic cannot establish preferences or causal effects.
References
Similar or alternative tools
- Lottery Branch Weighted Utility Term
Calculate one supplied lottery branch's expected-utility term.
- Risk Choice Stated Certain Ratio
Compare a stated certain value with a supplied expected lottery value.