Time-inconsistent stochastic optimal control problems and backward stochastic volterra integral equations
ESAIM: Control, Optimisation and Calculus of Variations, Tome 27 (2021), article no. 22

An optimal control problem is considered for a stochastic differential equation with the cost functional determined by a backward stochastic Volterra integral equation (BSVIE, for short). This kind of cost functional can cover the general discounting (including exponential and non-exponential) situations with a recursive feature. It is known that such a problem is time-inconsistent in general. Therefore, instead of finding a global optimal control, we look for a time-consistent locally near optimal equilibrium strategy. With the idea of multi-person differential games, a family of approximate equilibrium strategies is constructed associated with partitions of the time intervals. By sending the mesh size of the time interval partition to zero, an equilibrium Hamilton–Jacobi–Bellman (HJB, for short) equation is derived, through which the equilibrium value function and an equilibrium strategy are obtained. Under certain conditions, a verification theorem is proved and the well-posedness of the equilibrium HJB is established. As a sort of Feynman–Kac formula for the equilibrium HJB equation, a new class of BSVIEs (containing the diagonal value Z(r, r) of Z(⋅ , ⋅)) is naturally introduced and the well-posedness of such kind of equations is briefly presented.

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DOI : 10.1051/cocv/2021027
Classification : 93E20, 49N70, 60H20, 35F21, 49L20, 90C39
Keywords: Time-inconsistent optimal control problem, backward stochastic Volterra integral equation, stochastic differential games, equilibrium strategy, equilibrium Hamilton–Jacobi–Bellman equation
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     title = {Time-inconsistent stochastic optimal control problems and backward stochastic volterra integral equations},
     journal = {ESAIM: Control, Optimisation and Calculus of Variations},
     year = {2021},
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     doi = {10.1051/cocv/2021027},
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Wang, Hanxiao; Yong, Jiongmin. Time-inconsistent stochastic optimal control problems and backward stochastic volterra integral equations. ESAIM: Control, Optimisation and Calculus of Variations, Tome 27 (2021), article no. 22. doi: 10.1051/cocv/2021027

[1] N. Agram and B. Øksendal, Malliavin calculus and optimal control of stchastic Volterra equations. J. Optim. Theory Appl. 167 (2015) 1070–1094.

[2] A. Aman and M. N’Zi, Backward stochastic nonlinear Volterra integral equation with local Lipschitz drift. Probab. Math. Statist. 25 (2005) 105–127.

[3] V. V. Anh, W. Grecksch and J. Yong, Regularity of backward stochastic Volterra integral equations in Hilbert spaces. Stoch. Anal. Appl. 29 (2011) 146–168.

[4] C. Bender and S. Pokalyuk, Discretization of backward stochastic Volterra integral equations. Recent Developments in Computational Finance. Interdiscip. Math. Sci. 14 (2013) 245–278.

[5] T. Björk, M. Khapko and A. Murgoci, On time-inconsistent stochastic control in continuous time. Finance Stoch. 21 (2017) 331–360.

[6] T. Björk and A. Murgoci, A theory of Markovian time-inconsistent stochastic control in discrete time. Finance Stoch. 18 (2014) 545–592.

[7] T. Björk, A. Murgoci and X. Y. Zhou, Mean-variance portfolio optimization with state-dependent risk aversion. Math. Finance 24 (2014) 1–24.

[8] L. Di Persio Backward stochastic Volterra integral equation approach to stochastic differential utility. Int. Electr. J. Pure Appl. Math. 8 (2014) 11–15.

[9] J. Djordjević and S. Janković, On a class of backward stochastic Volterra integral equations. Appl. Math. Lett. 26 (2013) 1192–1197.

[10] J. Djordjević and S. Janković, Backward stochastic Volterra integral equations with additive perturbations. Appl. Math. Comput. 265 (2015) 903–910.

[11] D. Duffie and L. G. Epstein, Stochastic differential utility. Econometrica 60 (1992) 353–394.

[12] D. Duffie and L. G. Epstein, Asset pricing with stochastic differential utility. Re. Financ. Studi. 5 (1992) 411–436.

[13] N. Ei Karoui, S. Peng and M. C. Quenez, Backward stochastic differential equations in finance. Math. Finance 7 (1997) 1–71.

[14] I. Ekeland and A. Lazrak, Being Serious about Non-Commitment: Subgame Perfect Equilibrium in Continuoue Time. Preprint (2006). | arXiv

[15] I. Ekeland and A. Lazrak, The golden rule when preferences are time inconsistent. Math. Financ. Econ. 4 (2010) 29–55.

[16] I. Ekeland and T. A. Pirvu, Investment and consumption without commitment. Math. Financ. Econ. 2 (2008) 57–86.

[17] Y. Hu and B. Øksendal, Linear Volterra backward stochastic integral equations. Stochastic Process. Appl. 129 (2019) 626–633.

[18] Y. Hu, H. Jin and X. Y. Zhou, Time-inconsistent stochastic linear–quadratic control. SIAM J. Control Optim. 50 (2012) 1548–1572.

[19] Y. Hu, H. Jin, and X. Y. Zhou, Time-inconsistent stochastic linear-quadratic control: characterization and uniqueness of equilibrium. SIAM J. Control Optim. 55 (2017) 1261–1279.

[20] E. Kromer and L. Overbeck, Differentiability of BSVIEs and dynamical capital allocations. Int. J. Theor. Appl. Finance 20 (2017) 1750047.

[21] A. Lazrak, Generalized stochastic differential utility and preference for information. Ann. Appl. Probab. 14 (2004) 2149–2175.

[22] A. Lazrak and M. C. Quenez, A generalized stochastic differential utility. Math. Oper. Res. 28 (2003) 154–180.

[23] J. Lin, Adapted solution of a backward stochastic nonlinear Volterra integral equation. Stoch. Anal. Appl. 20 (2002) 165–183.

[24] J. Ma, P. Protter, and J. Yong, Solving forward-backward stochastic differential equations explicitly — four step scheme, Probab. Theory Related Fields 98 (1994) 339–359.

[25] J. Ma and J. Yong, Forward-Backward Stochastic Differential Equations and Their Applications. Vol. 1702 of Lecture Notes in Mathematics. Springer-Verlag, Berlin (1999).

[26] J. Marin-Solano and J. Navas, Consumption and portfolio rules for time-inconsistent investors. Euro. J. Oper. Res. 201 (2010) 860–872.

[27] J. Marin-Solano and E. V. Shevkoplyas, Non-constant discounting and differential games with random time horizon. Automatica 47 (2011) 2626–2638.

[28] H. Mei and J. Yong, Equilibrium strategies for time-inconsistent stochastic switching systems. ESAIM: COCV 25 (2019) 64.

[29] L. Overbeck and J. A. L. Röder, Path-dependent backward stochastic Volterra integral equations with jumps, differentiability and duality principle. Probab. Uncertain. Quant. Risk 3 (2018) 4.

[30] E. Pardoux and S. Peng, Adapted solution of a backward stochastic differential equation. Systems Control Lett. 14 (1990) 55–61.

[31] R. A. Pollak, Consistent planning. Rev. Econ. Stud. 35 (1968) 185–199.

[32] Y. Ren, On solutions of backward stochastic Volterra integral equations with jumps in Hilbert spaces. J. Optim. Theory Appl. 144 (2010) 319–333.

[33] Y. Shi, T. Wang and J. Yong, Mean-field backward stochastic Volterra integral equations. Discrete Contin. Dyn. Syst. Ser. B 18 (2013) 1929–1967.

[34] Y. Shi, T. Wang and J. Yong, Optimal control problems of forward-backward stochastic Volterra integral equations. Math. Control Relat. Fields 5 (2015) 613–649.

[35] H. Wang, Extended backward stochastic Volterra integral equations, quasilinear parabolic equations, and Feynman–Kac formula. Stoch. Dyn. 21 (2021) 2150004.

[36] H. Wang, J. Sun and J. Yong, Recursive utility processes, dynamic risk measures and quadratic backward stochastic Volterra integral equations. Appl. Math. Optim. (2019) . | DOI

[37] T. Wang, Linear quadratic control problems of stochastic Volterra integral equations. ESAIM: COCV 24 (2018) 1849–1879.

[38] T. Wang and J. Yong, Comparison theorems for some backward stochastic Volterra integral equations. Stochastic Process. Appl. 125 (2015) 1756–1798.

[39] T. Wang and J. Yong, Backward stochastic Volterra integral equations—representation of adapted solutions. Stochastic Process. Appl. 129 (2019) 4926–4964.

[40] T. Wangand H. Zhang, Optimal control problems of forward-backward stochastic Volterra integral equations with closed control regions. SIAM J. Control Optim. 55 (2017) 2574–2602.

[41] Z. Wang and X. Zhang, Non-Lipschitz backward stochastic Volterra type equations with jumps. Stoch. Dyn. 7 (2007) 479–496.

[42] Q. Wei, J. Yong and Z. Yu, Time-inconsistent recursive stochastic optimal control problems. SIAM J. Control Optim. 55 (2017) 4156–4201.

[43] W. Yan and J. Yong, Time-inconsistent optimal control problems and related issues. Vol. 164 of Modeling, Stochastic Control, Optimization, and Applications, Edited by G. Yin and Q. Zhang, IMA Volumes in Mathematics and Its Applications. Springer (2019) 533–569.

[44] J. Yong, Well-posedness and regularity of backward stochastic Volterra integral equations. Probab. Theory Related Fields 142 (2008) 21–77.

[45] J. Yong, Time-inconsistent optimal control problems and the equilibrium HJB equation. Math. Control Relat. Fields 2 (2012) 271–329.

[46] J. Yong, Time-inconsistent optimal control problems, in Proceedings of 2014 ICM, Section 16. Control Theory and Optimization (2014) 947–969.

[47] J. Yong, Linear-quadratic optimal control problems for mean-field stochastic differential equations–time-consistent solutions. Trans. Amer. Math. Soc. 369 (2017) 5467–5523.

[48] J. Yong, Representation of adapted solutions to backward stochastic Volterra integral equations. Scientia Sinica Mathematica 47 (2017) 1–12 (in Chinese).

[49] J. Yong and X. Y. Zhou, Stochastic Control: Hamiltonian Systems and HJB Equations. Springer-Verlag, New York (1999).

[50] X. Y. Zhou, Stochastic near-opyimal controls: necessary and sufficient conditions for near-optimality. SIAM J. Control Optim. 36 (1998) 929–947.

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