pith. sign in

arxiv: 2604.09033 · v1 · submitted 2026-04-10 · 🧮 math.PR

Uniform asymptotics for a multidimensional renewal risk model with random number of delayed claims and multivariate subexponentiality

Pith reviewed 2026-05-10 17:45 UTC · model grok-4.3

classification 🧮 math.PR
keywords multivariate risk modelrenewal counting processsubexponential distributionsdelayed claimsasymptotic analysisrare setsKaramata index
0
0 comments X

The pith

The probability that discounted aggregate claims enter rare sets in a renewal risk model with delayed claims admits uniform asymptotics determined by the multivariate subexponential tails.

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

This paper establishes uniform asymptotic formulas for the probability that the discounted sum of claims, including random numbers of delayed claims, enters certain rare sets over finite or infinite time horizons in a multidimensional renewal risk model with constant interest. These formulas hold when the main and delayed claim vectors are multivariate subexponential and fully incorporate the effects of the renewal counting process, the random delays, the interest rate, and various dependence structures between claims. A sympathetic reader cares because exact probabilities are typically intractable in such models, so these approximations enable reliable estimation of the risk of large losses or ruin in insurance and finance applications with multiple claim types. The results also include closure properties for the subexponential class and explicit formulas under regular variation, along with numerical validation.

Core claim

In a multivariate risk model driven by a common renewal process where each main claim vector is followed by a random number of delayed claim vectors, the entrance probability into a rare set A for the discounted aggregate claims process is asymptotically equivalent to an expression involving the integrated tail of the main claim distribution (adjusted for the interest and the random delays), uniformly in time for the finite horizon case, provided the claims are multivariate subexponential; for the infinite horizon a positive lower Karamata index is additionally required to ensure the equivalence holds. The asymptotics capture all sources of randomness and different dependence structures.

What carries the argument

The multivariate subexponential distribution class, which ensures that the tail of the sum or the maximum is governed by the individual tails in a specific way, allowing the rare-set probabilities to be reduced to tail integrals without losing the effects of dependencies and delays.

If this is right

  • The finite-time asymptotics hold with local uniformity over the time interval.
  • The results apply both when delayed claims have tails equivalent to main claims and when they are asymptotically negligible.
  • Under multivariate regular variation, more explicit and simpler asymptotic formulas are obtained.
  • Closure properties hold for the subexponential class with positive lower Karamata index under convolution and product convolution.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The uniform nature of the asymptotics suggests they can be used to approximate ruin probabilities even when the time horizon is random or data-driven.
  • These results may extend the applicability of subexponential techniques to portfolio risk management with correlated claim types across different lines of business.
  • Numerical accuracy shown in the paper indicates the approximations remain useful for practical threshold levels in insurance calculations.

Load-bearing premise

The main claim vectors and the delayed claim vectors both follow multivariate subexponential distributions, with the additional requirement of a positive lower Karamata index for the infinite time horizon case.

What would settle it

Numerical computation of the exact entrance probability for a concrete multivariate subexponential distribution at increasingly large thresholds and checking whether the ratio to the asymptotic expression approaches one.

read the original abstract

In this paper we examine a multivariate risk model, with common renewal counting process, constant interest rate, and each claim vector is accompanied by a random number of delayed claim vectors. The interest is focused on the asymptotic behavior of the entrance probability of the discounted aggregate claims into some rare-sets, over a finite and an infinite time horizon. Our results study the the case where the main claims and the delayed claims have in some sense, asymptotic equivalent tails, but also the case where the delayed claims are negligible with comparisons with the main claims. More precisely, our estimations over finite time horizon are equipped with local uniformity, and are valid under the assumption of multivariate subexponential distributions for the claim distributions. On the case of infinite time horizon we need a mild restriction on the distribution class of multivariate subexponential distributions with positive lower Karamata index. The asymptotic relations reflect completely as all the sources of randomness, under the concrete rare-sets A, and the different dependence structures as well, without loosing elegance in spite of their generality. Further, we provide some more explicit formulas, together with relaxations of some assumptions, for the claim distributions from the multivariate regular variation. For the proof of the main results on infinite time case and for the construction of examples of multivariate distributions we need some closure properties of subexponential distributions with positive lower Karamata index. Especially, we present some necessary and sufficient conditions for the closure property with respect to convolution and some sufficient conditions for the closure property with respect to product convolution. Finally, we carry out some numerical studies to show the accuracy of our asymptotic estimations.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 4 minor

Summary. The paper derives uniform asymptotic approximations, both local and global, for the finite- and infinite-horizon probabilities that the discounted aggregate claims process enters a rare set A in a multivariate renewal risk model driven by a common renewal counting process, constant interest rate, and a random number of delayed claim vectors. The main and delayed claim vectors are assumed to belong to the class of multivariate subexponential distributions (with positive lower Karamata index required for the infinite-horizon case). The asymptotics are shown to incorporate the renewal structure, discounting, arbitrary dependence, and the distinction between asymptotically equivalent tails and negligible delayed claims; explicit formulas are supplied for the multivariate regularly varying subcase, and closure properties under convolution and product convolution are established for the relevant distribution class.

Significance. If the derivations are correct, the work supplies a substantial extension of univariate subexponential risk asymptotics to the multivariate setting with delayed claims. The uniform character of the finite-horizon results and the explicit treatment of different dependence structures and rare-set geometries are technically valuable. The necessary-and-sufficient conditions for closure under convolution (and sufficient conditions for product convolution) for multivariate subexponentials with positive lower Karamata index constitute a useful contribution to the theory of heavy-tailed multivariate distributions. The numerical illustrations provide direct checks of the formulas.

major comments (2)
  1. §3.2, Theorem 3.3: the passage from the finite-horizon local-uniform asymptotics to the infinite-horizon statement invokes the closure under convolution proved in §4; however, the argument does not explicitly verify that the lower Karamata index remains positive after the random number of convolutions induced by the delay mechanism, which is load-bearing for the infinite-horizon claim.
  2. §5, Eq. (5.4): the explicit regularly-varying formula is stated to hold uniformly over the rare sets A, yet the proof sketch only controls the radial component; an additional argument is needed to justify uniformity with respect to the angular component when the dependence structure between main and delayed vectors is arbitrary.
minor comments (4)
  1. Abstract, line 3: 'the the case' is a typographical error.
  2. Abstract, line 7: 'loosing' should be 'losing'.
  3. Notation section: the symbol for the random delay count is introduced without an explicit range or moment assumption, which affects readability of the subsequent statements.
  4. Figure 1 caption: the legend does not distinguish the simulated paths from the asymptotic curves, reducing clarity.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful reading and constructive comments on our manuscript. We address each major comment point by point below and will incorporate the necessary clarifications and additions in the revised version.

read point-by-point responses
  1. Referee: §3.2, Theorem 3.3: the passage from the finite-horizon local-uniform asymptotics to the infinite-horizon statement invokes the closure under convolution proved in §4; however, the argument does not explicitly verify that the lower Karamata index remains positive after the random number of convolutions induced by the delay mechanism, which is load-bearing for the infinite-horizon claim.

    Authors: We agree that an explicit verification is required for rigor. The closure properties established in Section 4 (Theorem 4.1) are stated for fixed convolutions, but the delay mechanism introduces a random number of summands. In the revised manuscript we will add a short lemma (or remark following Theorem 4.1) showing that the positive lower Karamata index is preserved under random convolutions whenever the counting random variable has finite moments of all orders; the argument follows directly from the necessary-and-sufficient conditions already proved in Section 4 together with a standard truncation argument. This will be inserted before the proof of Theorem 3.3 so that the passage to the infinite-horizon case is fully justified. revision: yes

  2. Referee: §5, Eq. (5.4): the explicit regularly-varying formula is stated to hold uniformly over the rare sets A, yet the proof sketch only controls the radial component; an additional argument is needed to justify uniformity with respect to the angular component when the dependence structure between main and delayed vectors is arbitrary.

    Authors: We thank the referee for this observation. The proof sketch in Section 5 indeed focuses on the radial scaling; uniformity in the angular component follows from the definition of multivariate regular variation (vague convergence of the normalized measures on the unit sphere) and the fact that the limiting measure is continuous on the sphere under the joint regular-variation assumption. In the revised version we will expand the argument after Equation (5.4) to make this explicit: we invoke the uniform convergence theorem for regularly varying functions on compact angular sets and note that arbitrary dependence between main and delayed vectors is already encoded in the joint limiting measure, so no additional restriction on the dependence structure is needed. The uniformity over the class of rare sets A then follows immediately. revision: yes

Circularity Check

0 steps flagged

No significant circularity; derivation self-contained

full rationale

The paper derives uniform asymptotics for finite- and infinite-horizon entrance probabilities into rare sets A by assuming multivariate subexponentiality (with positive lower Karamata index for the infinite case) for main and delayed claim vectors. It explicitly proves the needed closure properties under convolution and product convolution as part of the argument rather than importing them via self-citation. The asymptotics incorporate the renewal counting process, random delays, discounting, and dependence structures directly from these tail assumptions and standard renewal theory, without any reduction of a claimed prediction to a fitted parameter, self-definition, or unverified self-citation chain. The central results remain independent of the paper's own outputs.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claims rest on the assumption that claim vectors belong to the class of multivariate subexponential distributions; this is a standard domain assumption in heavy-tailed risk theory rather than a new postulate invented by the paper.

axioms (1)
  • domain assumption Claim size vectors follow multivariate subexponential distributions (with positive lower Karamata index for infinite horizon).
    Invoked throughout the abstract as the condition under which the uniform asymptotics hold.

pith-pipeline@v0.9.0 · 5603 in / 1338 out tokens · 63591 ms · 2026-05-10T17:45:06.940900+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

50 extracted references · 50 canonical work pages · 2 internal anchors

  1. [1]

    N.H., Goldie, C.M., Teugels, J.L

    Bingham. N.H., Goldie, C.M., Teugels, J.L. \ (1987) Regular Variation Cambridge University Press, Cambridge

  2. [2]

    \ (2016) Stochastic Models with Power-Law Tails

    Buraczewski, D., Damek, E., Mikosch, T. \ (2016) Stochastic Models with Power-Law Tails . Springer, New York

  3. [3]

    Asymptotics for aggregated interdependent multivariate subexponential claims with general investment returns

    Chen, Z., Konstantinides, D.G., Passalidis, C.D. \ (2025) Asymptotics for aggregated interdependet multivariate subexponential claims with general investment returns. Preprint, arXiv:2507.23713

  4. [4]

    \ (2013) Uniform asymptotics for the finite-time ruin probabilities of two kinds of nonstandard bidimensional risk modes

    Chen, Y., Wang, L., Wang, Y. \ (2013) Uniform asymptotics for the finite-time ruin probabilities of two kinds of nonstandard bidimensional risk modes. J. Math. Anal. Appl. , 401, no. 1, 114--129

  5. [5]

    \ (2024) Multivariate regular varying insurance and financial risks in d -dimensional risk model

    Cheng, M., Konstantinides, D.G., Wang, D. \ (2024) Multivariate regular varying insurance and financial risks in d -dimensional risk model. J. Appl. Probab. , 61, no. 4, 1319 -- 1342

  6. [6]

    \ (1994) Subexponentiality of the product of independent random variables

    Cline, D.B.H., Samorodnitsky, G. \ (1994) Subexponentiality of the product of independent random variables. Stoch. Process. Appl. , 49, 75--98

  7. [7]

    \ (2013) An Introduction to Heavy-Tailed and Subexponential Distributions

    Foss, S., Korshunov, D., Zachary, S. \ (2013) An Introduction to Heavy-Tailed and Subexponential Distributions. Springer, New York, 2nd ed

  8. [8]

    \ (2014) Asymptotic ruin probabilities in a generalized bidimensional risk model perturbed by diffusion with constant force of interest

    Gao, Q., Yang, X. \ (2014) Asymptotic ruin probabilities in a generalized bidimensional risk model perturbed by diffusion with constant force of interest. J. Math. Anal. Appl. , 419, no. 2, 1193--1213

  9. [9]

    \ (2019) Asymptotics for a delay-claim risk model with diffusion, dependence structures and constant force of interest

    Gao, Q., Zhuang, J., Huang, Z. \ (2019) Asymptotics for a delay-claim risk model with diffusion, dependence structures and constant force of interest. J. Comput. Appl. Math. , 353, 219--231

  10. [10]

    \ (2009) Asymptotic tail probabilities of sums of dependent subexponential random variables

    Geluk, J., Tang, Q. \ (2009) Asymptotic tail probabilities of sums of dependent subexponential random variables. J. Theor. Probab. , 22, 871--882

  11. [11]

    \ (2008) A uniform asymptotic estimate for discounted aggregate claims with subexponential tails

    Hao, X., Tang, Q. \ (2008) A uniform asymptotic estimate for discounted aggregate claims with subexponential tails. Insur. Math. Econom. , 43, 116--120

  12. [12]

    \ (2025) Asymptotics for ruin probabilities of a bidimensional risk model with a random number of delayed claims

    Jia, Y., Chen, Z., Cheng, D. \ (2025) Asymptotics for ruin probabilities of a bidimensional risk model with a random number of delayed claims. Commun. Stat. Th. Meth. , 54, no. 10, 2990--3007

  13. [13]

    \ (2015) Uniform asymptotic estimate for finite-time ruin probabilities of a time-dependent bidimensional renewal model

    Jiang, T., Wang, Y., Chen, Y., Xu, H. \ (2015) Uniform asymptotic estimate for finite-time ruin probabilities of a time-dependent bidimensional renewal model. Insur. Math. Econom. , 64, 45--53

  14. [14]

    \ (2008) Sums of dependent non-negative random variables with subexponential tails

    Ko, B.W., Tang Q.H. \ (2008) Sums of dependent non-negative random variables with subexponential tails. J. Appl. Probab. , 45, 85--94

  15. [15]

    (2025) On the joint tail behavior of randomly weighted sums of dependent random variables with applications to ris k theory

    Konstantinides, D.G., Liu, J., Passalidis, C.D. \ (2026) Uniform asymptotics for a multidimensional renewal risk model with multivariate subexponential claims. Scand. Act. J. , p. 1 -- 21. Doi.org/10.1080/03461238.2025.2584008

  16. [16]

    (2024) Random vectors in the presence of a single big jump

    Konstantinides, D.G., Passalidis, C.D. \ (2024) Random vectors in the presence of a single big jump. Preprint, arXiv:2410.10292

  17. [17]

    Heavy-tailed random vectros: theory and applications

    Konstantinides, D.G., Passalidis, C.D. \ (2025) Heavy-tailed random vectors: theory and applications. Preprint, arXiv:2503.12842

  18. [18]

    \ (2025) A new approach in two-dimensional heavy-tailed distributions

    Konstantinides, D.G., Passalidis, C.D. \ (2025) A new approach in two-dimensional heavy-tailed distributions. Ann. Actuar. Scien. , 19, no.2, 317 -- 349

  19. [19]

    \ (2025) Uniform asymptotic estimates for ruin probabilities of a multidimensional risk model with c\' a dl\' a g returns and multivariate heavy-tailed claims

    Konstantinides, D.G., Passalidis, C.D. \ (2025) Uniform asymptotic estimates for ruin probabilities of a multidimensional risk model with c\' a dl\' a g returns and multivariate heavy-tailed claims. Insur. Math. Econom. , 125 , 103148

  20. [20]

    \ (2025) Multivariate subexponentiality and interplay of insurance and financial risks in a renewal risk model

    Konstantinides, D.G., Passalidis, C.D. \ (2025) Multivariate subexponentiality and interplay of insurance and financial risks in a renewal risk model. Preprint, arXiv:2510.17377

  21. [21]

    \ (2002) Estimates for the ruin probability in the classical risk model with constant interest force in the presence of heavy tails

    Konstantinides, D., Tang, Q., Tsitsiashvili, G. \ (2002) Estimates for the ruin probability in the classical risk model with constant interest force in the presence of heavy tails. Insur. Math. Econom. , 31, 447--460

  22. [22]

    \ (1966) Some concepts of dependence

    Lehmann, E.L. \ (1966) Some concepts of dependence. Ann. Math. Stat. , 37, 1137--1153

  23. [23]

    \ (2020) On a closure property of convolution equivalent class of distributions

    Leipus, R., S iaulys, J. \ (2020) On a closure property of convolution equivalent class of distributions. J. Math. Anal. Appl. , 490, no. 124226

  24. [24]

    \ (2023) Closure Properties for Heavy-Tailed and Related Distributions: An Overview

    Leipus, R., S iaulys, J., Konstantinides, D.G. \ (2023) Closure Properties for Heavy-Tailed and Related Distributions: An Overview. Springer Nature, Cham Switzerland

  25. [25]

    \ (2013) On pairwise quasi-asymptotically independent random variables and their applications

    Li, J. \ (2013) On pairwise quasi-asymptotically independent random variables and their applications. Stat. Prob. Lett. , 83, 2081--2087

  26. [26]

    \ (2016) Uniform asymptotics for a multidimensional time-dependent risk model with multivariate regularly varying claims and stochastic return

    Li, J. \ (2016) Uniform asymptotics for a multidimensional time-dependent risk model with multivariate regularly varying claims and stochastic return. Insur. Math. Econom. , 71, 195--204

  27. [27]

    \ (2023) Asymptotic ruin probabilities for a renewal risk model with a random number of delayed claims

    Li, J. \ (2023) Asymptotic ruin probabilities for a renewal risk model with a random number of delayed claims. J. Indust. Manag. Optim. , 19, no. 6, 3840--3853

  28. [28]

    \ (2024) Uniform asymptotics for a risk model with constant force of interest and a random number of delayed claims

    Liu, X., Gao, Q., Chen, Y. \ (2024) Uniform asymptotics for a risk model with constant force of interest and a random number of delayed claims. Stochastics , 97, no. 7, 1817--1839

  29. [29]

    \ (2025) Uniform asymptotics for a time-dependent bidimensional delay-claim risk model with stochastic return and dependent subexponential claims

    Lu, D., Qin, X., Yuan, M. \ (2025) Uniform asymptotics for a time-dependent bidimensional delay-claim risk model with stochastic return and dependent subexponential claims. Adv. Appl. Probab. , 1-37. Doi:10.1017/apr.2025.10038

  30. [30]

    \ (2007) Heavy-Tail Phenomena

    Resnick, S. \ (2007) Heavy-Tail Phenomena. Probabilistic and Statistical Modeling. Springer, New York

  31. [31]

    \ (2016) Stochastic Processes and Long Range Dependence Springer, New York

    Samorodnitsky, G. \ (2016) Stochastic Processes and Long Range Dependence Springer, New York

  32. [32]

    \ (2016) Multivariate subexponential distributions and their applications

    Samorodnitsky, G., Sun, J. \ (2016) Multivariate subexponential distributions and their applications. Extremes , 19, no. 2, 171--196

  33. [33]

    \ (2022) Uniform asymptotics for ruin probabilities of multidimensional risk models with stochastic returns and regular variation claims

    Shen, X., Yuan, M., Lu, D. \ (2022) Uniform asymptotics for ruin probabilities of multidimensional risk models with stochastic returns and regular variation claims. Commun. Stat. Th. Method. , 52, no. 19, 6878--6895

  34. [34]

    \ (1946) A note on comulative sums

    Stein, C. \ (1946) A note on comulative sums. Ann. Math. Stat. , 4, 498--499

  35. [35]

    \ (2004) Asymptotics for the finite-time ruin probability in the renewal risk model with consistent variation

    Tang, Q. \ (2004) Asymptotics for the finite-time ruin probability in the renewal risk model with consistent variation. Stoch. Models , 20, no. 3, 281--279

  36. [36]

    \ (2006) The subexponentiality of products revisited

    Tang, Q. \ (2006) The subexponentiality of products revisited. Extremes , 9, 231--241

  37. [37]

    \ (2003) Precise estimates for the ruin probability in finite horizon in a discrete-time model with heavy-tailed insurance and financial risks

    Tang, Q., Tsitsiashvili, G. \ (2003) Precise estimates for the ruin probability in finite horizon in a discrete-time model with heavy-tailed insurance and financial risks. Stoch. Process. Appl. , 108, 299--325

  38. [38]

    \ (2014) Randomly weighted sums of subexponential random variables with application to capital allocation

    Tang, Q., Yuan, Z. \ (2014) Randomly weighted sums of subexponential random variables with application to capital allocation. Extremes , 17, 467--493

  39. [39]

    \ (2016) Random difference equations with subexponential innovations

    Tang, Q., Yuan, Z. \ (2016) Random difference equations with subexponential innovations. Scien. China Math. , 59, 2411--2426

  40. [40]

    \ (2011) Randomly weighted sums of dependent subexponential random variables

    Wang, K. \ (2011) Randomly weighted sums of dependent subexponential random variables. Lith. Math. J. , 51, no. 4, 573--586

  41. [41]

    \ (1985) Ruin probabilities allowing for delay in claims settlement

    Waters, H.R., Papatriandafylou, A. \ (1985) Ruin probabilities allowing for delay in claims settlement. Insur. Math. Econom. , 4, no. 2, 113--122

  42. [42]

    \ (2018) A necessary and sufficient condition for the subexponentiality of product convolution

    Xu, H., Cheng, F., Wang, Y., Cheng, D. \ (2018) A necessary and sufficient condition for the subexponentiality of product convolution. Adv. Appl. Probab. 50, no.1, 57--73

  43. [43]

    \ (2019) On asymptotic finite-time ruin probabilities for a renewal risk model with subexponential main claims and delayed claims

    Yang, H., Li, J. \ (2019) On asymptotic finite-time ruin probabilities for a renewal risk model with subexponential main claims and delayed claims. Stat. Probab. Lett. , 58, 185--192

  44. [44]

    \ (2023) Asymptotic behavior of ruin probabilities in a multidimensional risk model with investment and multivariate regularly varying claims

    Yang, Y., Su, Q. \ (2023) Asymptotic behavior of ruin probabilities in a multidimensional risk model with investment and multivariate regularly varying claims. J. Math. Anal. Appl. , 525, 127319

  45. [45]

    \ (2021) Finite-time ruin probability of a perturbed risk model with dependent main and delayed claims

    Yang, Y., Wang, X., Zhang, Z. \ (2021) Finite-time ruin probability of a perturbed risk model with dependent main and delayed claims. Nonlin. Anal. Mod. Contr. , 26, no. 5, 801--820

  46. [46]

    \ (2011) Approximation of the tail probability of randomly weighted sums of dependent random variables with dominated variation

    Yi, L., Chen Y., Su, C. \ (2011) Approximation of the tail probability of randomly weighted sums of dependent random variables with dominated variation. J. Math. Anal. Appl., 376 , 365--372

  47. [47]

    \ (2001) Ruin probabilities for time-correlated claims in the compound binomial model

    Yuen, K.C., Guo, J.Y. \ (2001) Ruin probabilities for time-correlated claims in the compound binomial model. Insur. Math. Econom. , 29, no. 1, 47--57

  48. [48]

    \ (2005) On ultimate ruin in a delayed-claims risk model

    Yuen, K.C., Guo, J.Y., Ng, K.W. \ (2005) On ultimate ruin in a delayed-claims risk model. J. Appl. Probab. , 42, no. 1, 143--174

  49. [49]

    \ (2023) Asymptotics for a time-dependent by-claim model with dependent subexponential claims

    Yuan, M., Lu, D. \ (2023) Asymptotics for a time-dependent by-claim model with dependent subexponential claims. Insur. Math. Econom. , 112, 120--141

  50. [50]

    \ (2025) Asymptotics for a multidimensional risk model with a random number of delayed claims and multivariate regularly varying distribution

    Yuan, M., Lu, D., Fu, Y. \ (2025) Asymptotics for a multidimensional risk model with a random number of delayed claims and multivariate regularly varying distribution. Adv. Appl. Probab. , , 1--30