> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fincept.in/llms.txt
> Use this file to discover all available pages before exploring further.

# Expected Utility Calculation

> Calculate expected utility of a risky prospect (lottery) under Von Neumann-Morgenstern expected utility theory: EU = Σ p_i * U(x_i). Supports CARA, CRRA, and log utility functions. If probabilities not provided, assumes uniform distribution. Returns single expected utility value. Use for portfolio choice, insurance decisions, and risky choice analysis under rational expectations. [Tier: STANDARD, Credits: 2]



## OpenAPI

````yaml api-specs/economics.json post /quantlib/economics/utility/expected-utility
openapi: 3.1.0
info:
  title: FinceptQuantLib API - Economics
  description: >-
    Economics module endpoints for FinceptQuantLib API - general equilibrium,
    game theory, auctions, and utility functions
  version: 3.0.0
  contact:
    name: Fincept API Support
    url: https://fincept.in
servers:
  - url: https://api.fincept.in
    description: Fincept API Production Server
security:
  - APIKeyHeader: []
tags:
  - name: quantlib-economics
    description: >-
      Economics module - general equilibrium, game theory, auctions, and utility
      theory
    x-displayName: Economics
paths:
  /quantlib/economics/utility/expected-utility:
    post:
      tags:
        - quantlib-economics
      summary: Expected Utility Calculation
      description: >-
        Calculate expected utility of a risky prospect (lottery) under Von
        Neumann-Morgenstern expected utility theory: EU = Σ p_i * U(x_i).
        Supports CARA, CRRA, and log utility functions. If probabilities not
        provided, assumes uniform distribution. Returns single expected utility
        value. Use for portfolio choice, insurance decisions, and risky choice
        analysis under rational expectations. [Tier: STANDARD, Credits: 2]
      operationId: expected_utility_quantlib_economics_utility_expected_utility_post
      requestBody:
        content:
          application/json:
            schema:
              type: object
              required:
                - utility_type
                - outcomes
              properties:
                utility_type:
                  type: string
                  description: Type of utility function to use
                  enum:
                    - cara
                    - crra
                    - log
                  example: crra
                param:
                  type: number
                  description: >-
                    Utility function parameter (risk_aversion for CARA, gamma
                    for CRRA, unused for log)
                  example: 2
                  nullable: true
                outcomes:
                  type: array
                  description: Possible wealth outcomes
                  items:
                    type: number
                  minItems: 1
                  example:
                    - 8000
                    - 10000
                    - 12000
                probabilities:
                  type: array
                  description: >-
                    Probabilities for each outcome (must sum to 1, if null uses
                    uniform)
                  items:
                    type: number
                    minimum: 0
                    maximum: 1
                  example:
                    - 0.25
                    - 0.5
                    - 0.25
                  nullable: true
            example:
              utility_type: crra
              param: 2
              outcomes:
                - 8000
                - 10000
                - 12000
              probabilities:
                - 0.25
                - 0.5
                - 0.25
        required: true
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                type: object
                properties:
                  success:
                    type: boolean
                    example: true
                  data:
                    type: object
                    properties:
                      expected_utility:
                        type: number
                        description: Expected utility of the lottery
                        example: -0.0001021
              example:
                success: true
                data:
                  expected_utility: -0.0001021
        '401':
          $ref: '#/components/responses/UnauthorizedError'
        '402':
          $ref: '#/components/responses/InsufficientTierError'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                type: object
                properties:
                  detail:
                    type: array
                    items:
                      type: object
              example:
                detail:
                  - loc:
                      - body
                      - outcomes
                    msg: field required
                    type: value_error.missing
      security:
        - APIKeyHeader: []
components:
  responses:
    UnauthorizedError:
      description: Authentication information is missing or invalid
      content:
        application/json:
          schema:
            type: object
            properties:
              detail:
                type: string
                example: Invalid API key
    InsufficientTierError:
      description: API tier insufficient for this endpoint
      content:
        application/json:
          schema:
            type: object
            properties:
              detail:
                type: string
                example: Endpoint requires Basic tier or higher
  securitySchemes:
    APIKeyHeader:
      type: apiKey
      in: header
      name: X-API-Key
      description: >-
        API key for authentication. Get your key at
        https://api.fincept.in/auth/register

````