Paper: arXiv 2401.09054

Authors: Edoardo Berton, Alessandro Doldi, Marco Maggis

Abstract

We consider a family of conditional nonlinear expectations defined on the space of bounded random variables and indexed by the class of all the sub-sigma-algebras of a given underlying sigma-algebra. We show that if this family satisfies a natural consistency property, then it collapses to a conditional certainty equivalent defined in terms of a state-dependent utility function. This result is obtained by embedding our problem in a decision theoretical framework and providing a new characterization of the Sure-Thing Principle. In particular we prove that this principle characterizes those preference relations which admit consistent backward conditional projections. We build our analysis on state-dependent preferences for a general state space as in Wakker and Zank (1999) and show that their numerical representation admits a continuous version of the state-dependent utility. In this way, we also answer positively to a conjecture posed in the aforementioned paper.

Complexity vs Empirical Score

  • Math Complexity: 8.5/10
  • Empirical Rigor: 1.0/10
  • Quadrant: Lab Rats — theoretically deep, empirically untested

Why this score: This paper presents a highly rigorous mathematical analysis of decision theory and non-linear expectations, solving an open conjecture by Wakker and Zank (1999). However, it is entirely theoretical with no empirical data, backtesting, or code implementations.

Research Flowchart

  flowchart TD
    A[Research Goal: Characterize consistent conditional nonlinear expectations] --> B[Input Framework: Decision Theory & State-Dependent Preferences Wakker & Zank]
    B --> C[Method: Embed problem in decision theory & re-characterize Sure-Thing Principle]
    C --> D[Process: Analyze preference relations admitting consistent backward conditional projections]
    D --> E[Key Outcome 1: Family collapses to state-dependent conditional certainty equivalent]
    D --> F[Key Outcome 2: Proved continuous state-dependent utility conjecture]