Pith. sign in

REVIEW 3 major objections 3 minor 1 cited by

Optimal Policy Characterization for a Class of Multi-Dimensional Ergodic Singular Stochastic Control Problems

T0 review · 3 major / 3 minor · reviewed 2026-08-04 · deepseek-v4-flash

Pith's one-line read For a class of ergodic singular stochastic control problems with a one-dimensional controlled state and a multi-dimensional uncontrolled factor, the optimal policy is a Skorokhod reflection at factor-dependent boundaries obtained from an au

desk verdict Genuinely new multi-dimensional ergodic singular control / Dynkin game connection; both applications check out, with the usual rubber-meets-road gaps in delegated lemmas. read the letter →

arxiv 2510.11158 v2 pith:VP2OSDXC submitted 2025-10-13 math.OC math.PR

classification math.OCmath.PR MSC 93E0360G4049L2035R3590B05
keywords ergodicsingularstochasticcontrolDynkingamefreeboundarySkorokhodreflectionverificationtheoreminventorymanagementpartialobservationvalueprofile
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper proves that for a class of long-run-average (ergodic) singular stochastic control problems, where a one-dimensional controlled process is modulated by an uncontrolled multi-dimensional factor Y, the optimal policy has barrier form: reflect the controlled state at two Y-dependent boundaries a+(Y) and a-(Y). The value and boundaries come not from the ergodic Bellman equation but from an auxiliary zero-sum optimal stopping game, whose value function U serves as the derivative of a pseudo-potential V(x,y)=∫U(x',y)dx'. The authors give verification theorems showing that if U solves a two-obstacle free-boundary problem with the right monotonicity inequalities, then the reflection policy is optimal; they then fully solve two genuinely two-dimensional inventory problems, one with partially observable mean-reversion level and one with fully observable mean-reverting level.

What carries the argument

The load-bearing object is the auxiliary Dynkin game: a zero-sum game of optimal stopping in which one player chooses a stopping time and the other chooses a stopping time, with payoff built from the x-derivative of the running cost and the constants K±; its value U(x,y) plays the role of the derivative of a pseudo-potential. Free boundaries a+(y)<a-(y) split the state into stopping regions and the continuation region, and the optimal singular control is exactly Skorokhod reflection at these Y-dependent barriers. The verification rests on Hypothesis 2.2: U must solve the free-boundary problem classically and the inequalities (2.23)-(2.24) must hold outside the continuation region, supplying

What would settle it

Compute, for either Section 3 example, the long-run average cost of the Skorokhod reflection policy at the numerical solution of the free-boundary problem, and compare with a policy that occasionally lets X drift inside the continuation region before reflecting; if any such policy achieves strictly lower average cost, the characterization in Theorems 2.2 and 2.3 fails. A cheaper check: exhibit coefficients satisfying Assumption 2.1 for which the inequalities (2.23)-(2.24) fail at the boundary, since then Hypothesis 2.2 cannot hold.

Watch

Extended reading notes

Core claim

The central construction is the auxiliary Dynkin game defined in (2.22), whose value function U is used to build a pseudo-potential V(x,y)=∫_α^x U(x',y)dx' and a value profile λ(y) via (2.27). Theorems 2.2 and 2.3 show that, if U is a classical solution of the free-boundary problem (2.25) with boundaries a±(y) satisfying inequalities (2.23)-(2.24), then (V,λ) solves the auxiliary PDE (2.7), and the control that reflects X at a±(Y) is optimal. In the two inventory case studies the authors verify this hypothesis: in the partial-observation example, U∈C^1 is established via hypoellipticity and boundary regularity despite the degenerate parabolic structure; in the observable mean-reverting examp

Load-bearing premise

The whole construction depends on Hypothesis 2.2: the value U of the auxiliary Dynkin game must be a sufficiently regular classical solution of the two-obstacle free-boundary problem, with boundaries a± satisfying inequalities (2.23)-(2.24); if those fail, the constructed pseudo-potential need not satisfy the verification equation and the reflection policy may be suboptimal.

Editorial extensions

If this is right

  • If Hypothesis 2.2 holds, the optimal policy is fully characterized by the two boundaries a±(Y), with no need to solve the gradient-constrained ergodic Bellman equation.
  • The value of the ergodic control problem is the long-run time average of the value profile λ(Y_t); when Y is ergodic, this value is a constant independent of the initial state.
  • The two inventory models are solved completely: in the partial-observation case, the optimal policy reflects the inventory at belief-dependent boundaries driven by the filter; in the full-observation case, at Lipschitz-continuous boundaries driven by the mean-reversion level.
  • The representation remains valid even when the factor Y is not recurrent, with the value depending on the initial factor level.
  • Degeneracy of the state process in the partial-information example is overcome by showing the generator is hypoelliptic, so U is C^1 and the verification theorem still applies.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Beyond the paper: the same construction suggests a computational route—solve a two-obstacle optimal stopping problem rather than the ergodic variational inequality; the boundaries of the stopping set are then ready-made control barriers.
  • Beyond the paper: in the degenerate limit where Y is constant, formula (2.40) recovers the classical smooth-fit relation c(a-)+K-b = c(a+)-K+b, so the framework contains the standard one-dimensional barrier solution as a special case.
  • Beyond the paper: a natural stress test is to perturb the two examples by making Y mean-reverting with coefficients that violate condition b>δ or the parameter condition (3.29); the conjecture is that reflection remains optimal but boundary regularity degrades, which would test how much of the regularity machinery is truly needed.
  • Beyond the paper: the value-profile viewpoint suggests that for non-ergodic factors the correct solution concept is an initial-condition-dependent value rather than a single constant, which may matter for mean-field game analogues.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 3 minor

Summary. The paper characterizes optimal policies for a class of multi-dimensional ergodic singular stochastic control problems where a one-dimensional linearly controlled process is modulated by a multi-dimensional uncontrolled factor. The main contribution is a general verification framework: given a solution (V, λ) to an auxiliary PDE with gradient constraints, a Skorokhod-reflection control at Y-dependent free boundaries is optimal (Theorem 2.1). The construction of (V, λ) is then reduced to the analysis of an auxiliary Dynkin game: under Hypothesis 2.2, the pseudo-potential V is the integral of the Dynkin game's value U, and λ is given explicitly (Theorems 2.2 and 2.3). Two inventory problems are solved: a partially observable model with a two-state Markov chain, where the separated problem yields a degenerate diffusion and Theorem 2.3 applies after proving hypoellipticity, smooth fit, and verifying the key identity (2.35); and a fully observable model with an Ornstein-Uhlenbeck factor, where uniform ellipticity gives W^{2,∞}_{loc} regularity of U and Theorem 2.2 applies with Lipschitz boundaries.

Significance. If the claims hold, the paper provides the first systematic connection between multi-dimensional ergodic singular stochastic control and Dynkin games, yielding explicit optimal policies in two genuinely two-dimensional settings. The general theorems are well-structured and the case studies are substantial. The verification theorems are stated as conditional results with checkable hypotheses, which is appropriate for a first paper in a new direction. The paper also contains useful methodological developments: the hypoellipticity argument for the filter dynamics in Section 3.1 and the Lipschitz regularity of free boundaries in Section 3.2. The main load-bearing steps are argued carefully, with the only notable delegation being the Skorokhod reflection lemma (Lemma 3.13), which is plausible and supported by prior work. On balance, the result is significant and the technical execution appears sound.

major comments (3)
  1. [Lemma 3.13 / Skorokhod reflection problem] The existence of the reflection control with state-dependent, discontinuous boundaries a±(Π) is the key existence step for optimality in Section 3.1, but the proof is delegated to '[35, Section 4.3]' and '[34, Section 6.1]' with a sketch. In particular, Lemma 3.13 states that a solution to (3.65) exists and is admissible, but the verification of admissibility (the limit in (2.2)) is only one sentence. Since Theorem 3.15 relies on this lemma for the existence of the optimal control, I would like to see a more self-contained argument or a precise statement of which theorem in [35,34] applies to the present discontinuous-boundary setting. This is a normal reliance on prior results, but it is the one step I would want checked independently.
  2. [Theorem 2.3, Eq. (2.35)] The identity (2.35) is load-bearing: it replaces the direct computation of L V that was possible in Theorem 2.2. In Theorem 3.15 it is verified by direct computation for the specific model, which is fine. However, the general Theorem 2.3 is stated with (2.35) as an assumption, and the paper does not discuss when (2.35) is expected to hold beyond the example. This is not an error, but the theorem would be more useful if it stated a sufficient condition (e.g., V∈C^2( C) plus the free-boundary equation for U in C) that implies (2.35).
  3. [Hypothesis 2.2(II)] The inequalities (2.23)-(2.24) are assumed globally in x≥a−(y) and x≤a+(y), respectively. In the two case studies they are verified via the monotonicity of c' and the explicit bounds on a± from Lemma 3.4(ii). In the general statement, however, the hypotheses are stated as assumptions without a discussion of when they are natural or automatically satisfied. This is acceptable for a conditional theorem, but it would be helpful to mention that these inequalities are exactly what is needed to turn the free-boundary problem for U into the variational inequality for V.
minor comments (3)
  1. [Throughout] There are typographical errors and spacing issues (e.g., 'F∞', 'dP⊗dt' without spaces, missing parentheses in several displayed equations). For example, in the abstract 'F∞' appears in the definition of admissible controls, and in Eq. (3.29) the parentheses around 'sup' are missing. These should be corrected.
  2. [Section 3.2, proof of Lemma 3.16(iv)] In the proof of Lipschitz continuity of a+, the representation (3.80) is used to compute the derivative of aε+. It is not fully justified that (aε+(y), y) belongs to C for all ε>0 and that the implicit function theorem applies; this is briefly stated. A reference to a similar argument would help.
  3. [Remark 2.4] The remark explains why the argument does not work directly for the DPE. It is useful but would benefit from a more explicit explanation of the distinction between λ(y) and the constant value λ⋆.

Circularity Check

0 steps flagged · score 2.0 of 10

No significant circularity: the verification theorems are conditional but self-contained; the case studies independently verify the hypotheses.

full rationale

The paper's central derivation is not circular. Theorem 2.2 constructs the pseudo-potential V as the x-integral of the Dynkin-game value U and defines the value profile λ by (2.27); it then verifies directly, through equation (2.30) and the sign conditions (2.23)-(2.24), that the constructed pair solves the auxiliary PDE (2.7). This is a genuine verification step, not an equivalence-by-definition: U is defined independently by the Dynkin game (2.22), and the boundary functions a± arise from U's level sets rather than being fitted to the control problem's value. Theorem 2.1 then provides the lower and upper bounds that establish optimality of the reflection control, assuming such a control exists. The two applications are also self-contained in the relevant sense: Section 3.1 verifies Hypothesis 2.2 through Lemma 3.4, Lemma 3.6, and Theorem 3.9, and Section 3.2 does so through Lemma 3.16 and the cited elliptic-obstacle theory of Friedman. The main soft spots are technical rather than circular: Theorem 2.3's proof is omitted as completely analogous, and the existence of the Skorokhod reflection control in Lemma 3.13 is proved by a sketched recursive construction 'as in [35, Section 4.3] and [34, Section 6.1]', with minor use of the authors' prior work for auxiliary facts such as [34, Lemma A.1]. These are supporting technical lemmas, not the central claim, and they do not reduce the paper's predictions to its inputs. No fitted parameters are renamed as predictions, and no uniqueness theorem from the authors' own prior work is used to force the choice of boundaries. The paper's own Remark 3.1 about 'circularity of information' concerns the information structure of the partially observed control problem, not the derivation chain, and is resolved by the separated-problem formulation.

Assumptions & free parameters 1 free parameters · 6 assumptions · 0 invented entities

No parameters fitted to data. The only arbitrary constant α is a gauge freedom. The paper relies on a set of structural assumptions (Hypothesis 2.2, Assumptions 2.1/3.1-3.3) and standard external results; no new physical entities.

free parameters (1)
  • α = any point in (sup_y a+(y), inf_y a-(y))
    Chosen by hand to define V(x,y)=∫_α^x U(x',y)dx' and λ(y) in (2.26)-(2.27). The optimal control is independent of α (Section 2.3), so this is a gauge freedom, not a fitted constant.
assumptions (6)
  • domain assumption Hypothesis 2.2: there exist measurable a+<a- with inequalities (2.23)-(2.24) and U∈C^2(C)∩C solving the free-boundary problem (2.25).
    Load-bearing structural hypothesis for Theorems 2.2 and 2.3; verified in the two case studies but not proven for general problems.
  • domain assumption Assumption 2.1: Lipschitz/linear growth of coefficients, local Lipschitz joint conditions, growth of cost c.
    Standard SDE well-posedness and differentiability requirements.
  • domain assumption Assumption 3.1: c∈C^∞ strictly convex with polynomial growth and lim c'=±∞.
    Used in the first case study to get smoothness, monotonicity and inverse of c'.
  • domain assumption Assumption 3.2: δ large relative to γ, λ1, λ2, p.
    Technical condition ensuring uniform integrability in the proof of U_y smooth-fit (Theorem 3.9).
  • domain assumption Assumption 3.3: b>δ in observable case.
    Ensures Lipschitz continuity of free boundaries via the derivative bound in Lemma 3.16.
  • standard math External results: [30, Thm 2.1] Dynkin game saddle point; [72] Schwartz-solution regularity; [35,34] Skorokhod reflection construction; [76] flow diffeomorphism; [74] stochastic stability.
    Invoked as black boxes; the paper treats them as established.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Optimal Policy Characterization for a Class of Multi-Dimensional Ergodic Singular Stochastic Control Problems." pith.science (2026). https://pith.science/paper/VP2OSDXC

@misc{pith2026251011158,
  author       = {Pith},
  title        = {Pith review of: Optimal Policy Characterization for a Class of Multi-Dimensional Ergodic Singular Stochastic Control Problems},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/VP2OSDXC}},
  note         = {Machine review of arXiv:2510.11158}
}
read the original abstract

In ergodic singular stochastic control problems, a decision-maker can instantaneously adjust the evolution of a state variable using a control of bounded variation, with the goal of minimizing a long-term average cost functional. The cost of control is proportional to the magnitude of adjustments. This paper characterizes the optimal policy and the value in a class of multi-dimensional ergodic singular stochastic control problems. These problems involve a linearly controlled one-dimensional stochastic differential equation, whose coefficients, along with the cost functional to be optimized, depend on a multi-dimensional uncontrolled process Y. We first provide general verification theorems providing an optimal control in terms of a Skorokhod reflection at Y-dependent free boundaries, which emerge from the analysis of an auxiliary Dynkin game. We then fully solve two two-dimensional optimal inventory management problems. To the best of our knowledge, this is the first paper to establish a connection between multi-dimensional ergodic singular stochastic control and optimal stopping, and to exploit this connection to achieve a complete solution in a genuinely two-dimensional setting.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Robust Ergodic Control of Jump-Diffusion Systems under Drift and Intensity Uncertainty

    math.OC 2026-05 unverdicted novelty 6.0 of 10

    Robust ergodic singular control for jump-diffusions with drift and intensity uncertainty reduces the HJB to a nonlinear integro-differential free-boundary problem whose worst-case model is bang-bang and whose optimal ...

Reference graph

Works this paper leans on

84 extracted references · 4 linked inside Pith · cited by 1 Pith paper

  1. [1]

    L. H. R. Alvarez. A class of solvable stationary singular stochastic control problems, 2018

  2. [2]

    L. H. R. Alvarez E. and A. Hening. Optimal sustainable harvesting of populations in random environ- ments.Stochastic Process. Appl., 150:678–698, 2022

  3. [3]

    Arapostathis, A

    A. Arapostathis, A. Biswas, and G. Pang. Ergodic control of multi-classM/M/N+Mqueues in the Halfin-Whitt regime.Ann. Appl. Probab., 25(6):3511–3570, 2015

  4. [4]

    Arapostathis and G

    A. Arapostathis and G. Pang. Ergodic diffusion control of multiclass multi-pool networks in the Halfin- Whitt regime.Ann. Appl. Probab., 26(5):3110–3153, 2016

  5. [5]

    Bain and D

    A. Bain and D. Crisan.Fundamentals of stochastic filtering, volume 60 ofStochastic Modelling and Applied Probability. Springer, New York, 2009

  6. [6]

    F. M. Baldursson and I. Karatzas. Irreversible investment and industry equilibrium.Finance and stochastics, 1:69–89, 1996

  7. [7]

    Bandini, T

    E. Bandini, T. De Angelis, G. Ferrari, and F. Gozzi. Optimal dividend payout under stochastic dis- counting.Math. Finance, 32(2):627–677, 2022. 34 A. CAL VIA, F. CANNEROZZI, AND G. FERRARI

  8. [8]

    Bensoussan.Stochastic control of partially observable systems

    A. Bensoussan.Stochastic control of partially observable systems. Cambridge University Press, Cam- bridge, 1992

Show all 84 references
  1. [9]

    Bensoussan and J.-L

    A. Bensoussan and J.-L. Lions.Applications of variational inequalities in stochastic control, volume 12 ofStudies in Mathematics and its Applications. North-Holland Publishing Co., Amsterdam-New York,

  2. [10]

    Boetius and M

    F. Boetius and M. Kohlmann. Connections between optimal stopping and singular stochastic control. Stochastic Process. Appl., 77(2):253–281, 1998

  3. [11]

    Boryc and L

    M. Boryc and L. Kruk. Characterization of the optimal policy for a multidimensional parabolic singular stochastic control problem.SIAM J. Control Optim., 54(3):1657–1677, 2016

  4. [12]

    Budhiraja, A

    A. Budhiraja, A. P. Ghosh, and C. Lee. Ergodic rate control problem for single class queueing networks. SIAM J. Control Optim., 49(4):1570–1606, 2011

  5. [13]

    Cadenillas, P

    A. Cadenillas, P. Lakner, and M. Pinedo. Optimal control of a mean-reverting inventory.Operations research, 58(6):1697–1710, 2010

  6. [14]

    Callegaro, C

    G. Callegaro, C. Ceci, and G. Ferrari. Optimal reduction of public debt under partial observation of the economic growth.Finance Stoch., 24(4):1083–1132, 2020

  7. [15]

    Cannerozzi and G

    F. Cannerozzi and G. Ferrari. Cooperation, correlation and competition in ergodicN-player games and mean-field games of singular controls: A case study.ArXiv preprint arXiv:2404.15079, 2024

  8. [16]

    H. Cao, J. Dianetti, and G. Ferrari. Stationary discounted and ergodic mean field games with singular controls.Math. Oper. Res., 48(4):1871–1898, 2023

  9. [17]

    M. B. Chiarolla and U. G. Haussmann. The optimal control of the cheap monotone follower.Stochastics Stochastics Rep., 49(1-2):99–128, 1994

  10. [18]

    M. B. Chiarolla and U. G. Haussmann. Controlling inflation: the infinite horizon case.Appl. Math. Optim., 41(1):25–50, 2000

  11. [19]

    Christensen, A

    S. Christensen, A. r. Holk Thomsen, and L. Trottner. Data-driven rules for multidimensional reflection problems.SIAM/ASA J. Uncertain. Quantif., 12(4):1240–1272, 2024

  12. [20]

    Cohen, A

    A. Cohen, A. Hening, and C. Sun. Optimal ergodic harvesting under ambiguity.SIAM J. Control Optim., 60(2):1039–1063, 2022

  13. [21]

    Cohen and C

    A. Cohen and C. Sun. Existence of optimal stationary singular controls and mean field game equilibria. Mathematics of Operations Research, 2025

  14. [22]

    J. G. Dai and D. Yao. Brownian inventory models with convex holding cost, Part 1: Average-optimal controls.Stoch. Syst., 3(2):442–499, 2013

  15. [23]

    De Angelis, S

    T. De Angelis, S. Federico, and G. Ferrari. Optimal boundary surface for irreversible investment with stochastic costs.Math. Oper. Res., 42(4):1135–1161, 2017

  16. [24]

    De Angelis and G

    T. De Angelis and G. Ferrari. Stochastic nonzero-sum games: a new connection between singular control and optimal stopping.Adv. in Appl. Probab., 50(2):347–372, 2018

  17. [25]

    De Angelis and G

    T. De Angelis and G. Peskir. GlobalC1 regularity of the value function in optimal stopping problems. Ann. Appl. Probab., 30(3):1007–1031, 2020

  18. [26]

    De Angelis and G

    T. De Angelis and G. Stabile. On Lipschitz continuous optimal stopping boundaries.SIAM J. Control Optim., 57(1):402–436, 2019

  19. [27]

    Dianetti and G

    J. Dianetti and G. Ferrari. Multidimensional singular control and related Skorokhod problem: sufficient conditions for the characterization of optimal controls.Stochastic Process. Appl., 162:547–592, 2023

  20. [28]

    Dianetti, G

    J. Dianetti, G. Ferrari, and I. Tzouanas. Ergodic mean-field games of singular control with regime- switching (extended version).arXiv preprint arXiv:2307.12012, 2023

  21. [29]

    E. B. Dynkin.Markov processes. Vols. I, II, volume Band 121, 122 ofDie Grundlehren der mathematis- chen Wissenschaften. Springer-Verlag, Berlin-Göttingen-Heidelberg; Academic Press, Inc., Publishers, New York, 1965. Translated with the authorization and assistance of the autho...

  22. [30]

    Ekström and G

    E. Ekström and G. Peskir. Optimal stopping games for Markov processes.SIAM J. Control Optim., 47(2):684–702, 2008

  23. [31]

    P. A. Ernst and H. Mei. The minimax Wiener sequential testing problem.SIAM J. Control Optim., 63(1):206–226, 2025

  24. [32]

    P. A. Ernst, H. Mei, and G. Peskir. Quickest real-time detection of multiple Brownian drifts.SIAM J. Control Optim., 62(3):1832–1856, 2024

  25. [33]

    P. A. Ernst and G. Peskir. The gapeev-shiryaev conjecture.arXiv preprint arXiv:2405.01685, 2024

  26. [34]

    Federico, G

    S. Federico, G. Ferrari, and N. Rodosthenous. Two-sided singular control of an inventory with unknown demand trend.SIAM J. Control Optim., 61(5):3076–3101, 2023

  27. [35]

    Federico and H

    S. Federico and H. Pham. Characterization of the optimal boundaries in reversible investment problems. SIAM J. Control Optim., 52(4):2180–2223, 2014. MULTI-DIMENSIONAL ERGODIC SINGULAR STOCHASTIC CONTROL 35

  28. [36]

    G. Ferrari. On the optimal management of public debt: a singular stochastic control problem.SIAM J. Control Optim., 56(3):1938–1975, 2018

  29. [37]

    Ferrari and S

    G. Ferrari and S. Zhu. On a merton problem with irreversible healthcare investment.ArXiv preprint 2212.05317, 2023

  30. [38]

    W. H. Fleming and H. M. Soner.Controlled Markov processes and viscosity solutions, volume 25 of Stochastic Modelling and Applied Probability. Springer, New York, second edition, 2006

  31. [39]

    Friedman.Variational principles and free-boundary problems

    A. Friedman.Variational principles and free-boundary problems. A Wiley-Interscience Publication. John Wiley & Sons, Inc., New York, 1982. Pure and Applied Mathematics

  32. [40]

    Gilbarg and N

    D. Gilbarg and N. S. Trudinger.Elliptic partial differential equations of second order. Classics in Mathematics. Springer-Verlag, Berlin, 2001. Reprint of the 1998 edition

  33. [41]

    Glover and G

    K. Glover and G. Peskir. Quickest detection problems for Ornstein-Uhlenbeck processes.Math. Oper. Res., 49(2):1045–1064, 2024

  34. [42]

    S. K. Goyal and B. C. Giri. Recent trends in modeling of deteriorating inventory.European Journal of operational research, 134(1):1–16, 2001

  35. [43]

    K. L. Helmes, R. H. Stockbridge, and C. Zhu. Continuous inventory models of diffusion type: long-term average cost criterion.Ann. Appl. Probab., 27(3):1831–1885, 2017

  36. [44]

    K. L. Helmes, R. H. Stockbridge, and C. Zhu. A weak convergence approach to inventory control using a long-term average criterion.Adv. in Appl. Probab., 50(4):1032–1074, 2018

  37. [45]

    Y. Hu, Z. Liu, and J. Wu. Optimal impulse control of a mean-reverting inventory with quadratic costs. J. Ind. Manag. Optim., 14(4):1685–1700, 2018

  38. [46]

    R. Hynd. The eigenvalue problem of singular ergodic control.Comm. Pure Appl. Math., 65(5):649–682, 2012

  39. [47]

    Ikeda and S

    N. Ikeda and S. Watanabe. A comparison theorem for solutions of stochastic differential equations and its applications.Osaka Math. J., 14(3):619–633, 1977

  40. [48]

    Asingularcontrolproblemwithanexpectedandapathwiseergodicperformance criterion.J

    A.JackandM.Zervos. Asingularcontrolproblemwithanexpectedandapathwiseergodicperformance criterion.J. Appl. Math. Stoch. Anal., pages Art. ID 82538, 19, 2006

  41. [49]

    Kallenberg.Foundations of modern probability

    O. Kallenberg.Foundations of modern probability. Probability and its Applications (New York). Springer-Verlag, New York, second edition, 2002

  42. [50]

    Karatzas

    I. Karatzas. A class of singular stochastic control problems.Adv. in Appl. Probab., 15(2):225–254, 1983

  43. [51]

    Karatzas and S

    I. Karatzas and S. E. Shreve. Connections between optimal stopping and singular stochastic control. I. Monotone follower problems.SIAM J. Control Optim., 22(6):856–877, 1984

  44. [52]

    Karatzas and S

    I. Karatzas and S. E. Shreve.Brownian motion and stochastic calculus, volume 113 ofGraduate Texts in Mathematics. Springer-Verlag, New York, second edition, 1991

  45. [53]

    Karatzas and H

    I. Karatzas and H. Wang. Connections between bounded-variation control and Dynkin games. In Optimal control and partial differential equations, pages 363–373. IOS, Amsterdam, 2001

  46. [54]

    E. V. Krichagina and M. I. Taksar. Asymptotically optimal policies for controlled queues in heavy traffic. InStochastic theory and adaptive control (Lawrence, KS, 1991), volume 184 ofLect. Notes Control Inf. Sci., pages 256–269. Springer, Berlin, 1992

  47. [55]

    E. V. Krichagina and M. I. Taksar. Diffusion approximation forGI/G/1controlled queues.Queueing Systems Theory Appl., 12(3-4):333–367, 1992

  48. [56]

    L. Kruk. Optimal policies forn-dimensional singular stochastic control problems. I. The Skorokhod problem.SIAM J. Control Optim., 38(5):1603–1622, 2000

  49. [57]

    L. Kruk. Optimal policies forn-dimensional singular stochastic control problems. II. The radially symmetric case. Ergodic control.SIAM J. Control Optim., 39(2):635–659, 2000

  50. [58]

    Kunwai, F

    K. Kunwai, F. Xi, G. Yin, and C. Zhu. On an ergodic two-sided singular control problem.Appl. Math. Optim., 86(2):Paper No. 26, 34, 2022

  51. [59]

    T. G. Kurtz and R. H. Stockbridge. Existence of Markov controls and characterization of optimal Markov controls.SIAM J. Control Optim., 36(2):609–653, 1998

  52. [60]

    Liang, Z

    G. Liang, Z. Liu, and M. Zervos. Singular Stochastic Control Problems Motivated by the Optimal Sustainable Exploitation of an Ecosystem.SIAM J. Control Optim., 63(3):2029–2052, 2025

  53. [61]

    R. S. Liptser and A. N. Shiryaev.Statistics of random processes. II., volume 6 ofApplications of Mathematics (New York). Springer-Verlag, Berlin, expanded edition, 2001. Applications, Translated from the 1974 Russian original by A. B. Aries, Stochastic Modelling and Applied Pr...

  54. [62]

    R. S. Liptser and A. N. Shiryayev.Statistics of random processes. I, volume Vol. 5 ofApplications of Mathematics. Springer-Verlag, New York-Heidelberg, 1977. General theory, Translated by A. B. Aries

  55. [63]

    J. Liu, K. F. C. Yiu, and A. Bensoussan. Ergodic control for a mean reverting inventory model.J. Ind. Manag. Optim., 14(3):857–876, 2018. 36 A. CAL VIA, F. CANNEROZZI, AND G. FERRARI

  56. [64]

    Løkka and M

    A. Løkka and M. Zervos. A model for the long-term optimal capacity level of an investment project. Int. J. Theor. Appl. Finance, 14(2):187–196, 2011

  57. [65]

    Løkka and M

    A. Løkka and M. Zervos. Long-term optimal investment strategies in the presence of adjustment costs. SIAM J. Control Optim., 51(2):996–1034, 2013

  58. [66]

    Menaldi and M

    J.-L. Menaldi and M. Robin. On optimal ergodic control of diffusions with jumps. InStochastic analy- sis, control, optimization and applications, Systems Control Found. Appl., pages 439–456. Birkhäuser Boston, Boston, MA, 1999

  59. [67]

    Menaldi, M

    J.-L. Menaldi, M. Robin, and M. I. Taksar. Singular ergodic control for multidimensional Gaussian processes.Math. Control Signals Systems, 5(1):93–114, 1992

  60. [68]

    J. R. Norris.Markov chains, volume 2 ofCambridge Series in Statistical and Probabilistic Mathematics. Cambridge University Press, Cambridge, 1998. Reprint of 1997 original

  61. [69]

    Nualart.The Malliavin calculus and related topics

    D. Nualart.The Malliavin calculus and related topics. Probability and its Applications (New York). Springer-Verlag, Berlin, second edition, 2006

  62. [70]

    S. C. Perera and S. P. Sethi. A survey of stochastic inventory models with fixed costs: Optimality of (s, s) and (s, s)-type policies—discrete-time case.Production and Operations Management, 32(1):131–153, 2023

  63. [71]

    G. Peskir. Optimal stopping games and Nash equilibrium.Teor. Veroyatn. Primen., 53(3):623–638, 2008

  64. [72]

    Weaksolutionsinthesenseofschwartztodynkin’scharacteristicoperatorequation.Potential Anal., 2025

    G.Peskir. Weaksolutionsinthesenseofschwartztodynkin’scharacteristicoperatorequation.Potential Anal., 2025

  65. [73]

    Possamaï, H

    D. Possamaï, H. Mete Soner, and N. Touzi. Homogenization and asymptotics for small transaction costs: the multidimensional case.Comm. Partial Differential Equations, 40(11):2005–2046, 2015

  66. [74]

    P. E. Protter.Stochastic integration and differential equations, volume 21 ofStochastic Modelling and Applied Probability. Springer-Verlag, Berlin, second edition, 2005. Corrected third printing

  67. [75]

    F. Raafat. Survey of literature on continuously deteriorating inventory models.Journal of the Opera- tional Research society, 42(1):27–37, 1991

  68. [76]

    L. C. G. Rogers and D. Williams.Diffusions, Markov processes, and martingales. Vol. 2. Cambridge Mathematical Library. Cambridge University Press, Cambridge, 2000. Itô calculus, Reprint of the second (1994) edition

  69. [77]

    H. M. Soner and S. E. Shreve. Regularity of the value function for a two-dimensional singular stochastic control problem.SIAM J. Control Optim., 27(4):876–907, 1989

  70. [78]

    H. M. Soner and N. Touzi. Homogenization and asymptotics for small transaction costs.SIAM J. Control Optim., 51(4):2893–2921, 2013

  71. [79]

    M. I. Taksar. Average optimal singular control and a related stopping problem.Math. Oper. Res., 10(1):63–81, 1985

  72. [80]

    Weerasinghe

    A. Weerasinghe. An abelian limit approach to a singular ergodic control problem.SIAM J. Control Optim., 46(2):714–737, 2007

  73. [81]

    A. P. N. Weerasinghe. Stationary stochastic control for Itô processes.Adv. in Appl. Probab., 34(1):128– 140, 2002

  74. [82]

    W. M. Wonham. On the separation theorem of stochastic control.SIAM J. Control, 6:312–326, 1968

  75. [83]

    D. Yao, X. Chao, and J. Wu. Optimal control policy for a Brownian inventory system with concave ordering cost.J. Appl. Probab., 52(4):909–925, 2015

  76. [1982]

    Translated from the French

Pith tools

Reviewed August 4, 2026 · model on record in the stance chip above.