{"title":"The joint model of default and prepayment for a mortgage loan and its application in mortgage insurance","authors":"Lan Bu , Fang Wang , Jingping Yang","doi":"10.1016/j.insmatheco.2026.103227","DOIUrl":null,"url":null,"abstract":"<div><div>In a portfolio of loans, default and prepayment are two competing events, and only the time and type of the first event to occur can be observed. Modeling the competing risks is crucial for mortgage insurance. This paper focuses on modeling the joint distribution of the time to default and the time to prepayment by considering two components: subdistributions of the time to default and time to prepayment, and a copula to model their dependence structure, where the subdistributions are estimated from the portfolio data, and the copula is chosen by concentrating on some optimal criteria.</div><div>For this purpose, we discuss the compatibility of a copula with the given subdistributions, and provide a method for deriving the marginal distributions of default and prepayment from the subdistributions and a compatible copula. Moreover, two criteria are proposed for finding a copula compatible with the given subdistributions. For estimating the subdistributions, a bilinear model is proposed. The asymptotic properties of the model’s estimators are proved. Additionally, a simulation study demonstrates the consistency of the estimators by considering both large and small sample cases. Finally, an empirical study is performed to estimate the subdistributions with static and time-varying covariates, and to identify compatible copulas under the proposed criteria. The application of the proposed method is further highlighted for determining premiums of mortgage insurance.</div></div>","PeriodicalId":54974,"journal":{"name":"Insurance Mathematics & Economics","volume":"127 ","pages":"Article 103227"},"PeriodicalIF":2.2000,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Insurance Mathematics & Economics","FirstCategoryId":"96","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S016766872600017X","RegionNum":2,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/1/29 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"ECONOMICS","Score":null,"Total":0}
引用次数: 0
Abstract
In a portfolio of loans, default and prepayment are two competing events, and only the time and type of the first event to occur can be observed. Modeling the competing risks is crucial for mortgage insurance. This paper focuses on modeling the joint distribution of the time to default and the time to prepayment by considering two components: subdistributions of the time to default and time to prepayment, and a copula to model their dependence structure, where the subdistributions are estimated from the portfolio data, and the copula is chosen by concentrating on some optimal criteria.
For this purpose, we discuss the compatibility of a copula with the given subdistributions, and provide a method for deriving the marginal distributions of default and prepayment from the subdistributions and a compatible copula. Moreover, two criteria are proposed for finding a copula compatible with the given subdistributions. For estimating the subdistributions, a bilinear model is proposed. The asymptotic properties of the model’s estimators are proved. Additionally, a simulation study demonstrates the consistency of the estimators by considering both large and small sample cases. Finally, an empirical study is performed to estimate the subdistributions with static and time-varying covariates, and to identify compatible copulas under the proposed criteria. The application of the proposed method is further highlighted for determining premiums of mortgage insurance.
期刊介绍:
Insurance: Mathematics and Economics publishes leading research spanning all fields of actuarial science research. It appears six times per year and is the largest journal in actuarial science research around the world.
Insurance: Mathematics and Economics is an international academic journal that aims to strengthen the communication between individuals and groups who develop and apply research results in actuarial science. The journal feels a particular obligation to facilitate closer cooperation between those who conduct research in insurance mathematics and quantitative insurance economics, and practicing actuaries who are interested in the implementation of the results. To this purpose, Insurance: Mathematics and Economics publishes high-quality articles of broad international interest, concerned with either the theory of insurance mathematics and quantitative insurance economics or the inventive application of it, including empirical or experimental results. Articles that combine several of these aspects are particularly considered.