Equilibrium Strategies for Singular Dividend Control Problems under the Mean-Variance Criterion
Jingyi Cao, Dongchen Li, Virginia R. Young, Bin Zou
TL;DR
This paper addresses a mean-variance (MV) mean-variance dividend problem under a singular control framework with dividends paid up to the endogenous ruin time $\tau$. It develops a new verification theorem for MV with the integral objective $Y_t = \int_t^\tau e^{-\rho(s-t)} dD_s$, yielding a three-function extended HJB system with $V$, $G$, and $H$, and characterizes time-consistent equilibrium strategies via a pay region $\mathrm{P}$ and a no-transaction region $\mathrm{NT}$ coupled to a Skorokhod reflection problem. The authors obtain two main equilibria: (i) for large risk aversion $\gamma \ge \dfrac{2a}{b^2}$, pay all surplus immediately; (ii) for small $\gamma$, a time-independent barrier strategy with barrier $\tilde{x}$ and explicit forms for $G$, $H$, and $V$ in the two regions, verified under a concavity condition. Numerical examples illustrate the barrier behavior, show a threshold $\bar{\gamma}$ below which the barrier is viable, and reveal open questions for intermediate $\gamma$. The results contribute a novel MV-singular-control framework for dividends with endogenously determined stopping times and connect to existing literature on time-inconsistent control and equilibrium strategies.
Abstract
We revisit the optimal dividend problem of de Finetti by adding a variance term to the usual criterion of maximizing the expected discounted dividends paid until ruin, in a singular control framework. Investors do not like variability in their dividend distribution, and the mean-variance (MV) criterion balances the desire for large expected dividend payments with small variability in those payments. The resulting MV singular dividend control problem is time-inconsistent, and we follow a game-theoretic approach to find a time-consistent equilibrium strategy. Our main contribution is a new verification theorem for the novel dividend problem, in which the MV criterion is applied to an integral of the control until ruin, a random time that is endogenous to the problem. We demonstrate the use of the verification theorem in two cases for which we obtain the equilibrium dividend strategy (semi-)explicitly, and we provide a numerical example to illustrate our results.
