Description: This paper introduces actuaries to the concept of 'copulas,' a tool for understanding relationships among multivariate outcomes. A copula is a function that links univariate marginals to their full multivariate distribution. Recently, there has been a rapidly developing literature on the statistical properties and applications of copulas. This paper explores some of these practical applications, including estimation of joint life mortality and multidecrement models. In addition, the paper describes basic properties of copulas, their relationships to measures of dependence and several families of copulas that have appeared in the literature. This paper will also be useful to those who wish to use copulas for statistical inference. Statistical inference procedures are illustrated using insurance company data on losses and expenses. For this data, the paper shows how to fit copulas and describes their usefulness by pricing a reinsurance contract and estimating expenses for pre-specified losses.

Description: Stochastic approximation is a powerful tool for sequential estimation of zero points of a function. In this paper, this methodology is defined and is shown to be related to a broad class of credibility formulae derived for the Exponential Dispersion Family. The authors further consider a Location Dispersion Family which is rich enough and for which no simple credibility formula exists. For this case, a Generalized Sequential Credibility Formula is suggested and an optimal stepwise gain sequence is derived.

Description: This paper presents an unbiased, consistent and asymptotically efficient estimator based on importance sampling variance reduction technique in the framework of Monte Carlo simulation methods. It shows that the estimator is highly efficient in terms of number of computations. Using the Pollaczeck-Khinchine formula, the authors extend the use of the estimator to the calculation of ultimate ruin probabilities in the context of the Classical case of Risk Theory and compare their results with recent actuarial literature using the same methodology.

Description: Design and future maintenance of an asset portfolio backing a new line of business is critical for proper asset and liability management for that business. Most portfolio optimization methods utilize linear or quadratic programming and require the user to specify the asset and liability attributes and cash flows into the program. The programmer must also supply an objective function to allow the program to find the optimal asset mix for the associated liabilities. Two problems with this approach are that the liability cash flows are fairly static and that one must frequently rebalance the portfolio. An alternative approach would be to develop a corporate model of both the assets and liabilities and incorporate various economic scenarios as input into the model. Asset strategies would be measured against a specific objective function that is calculated by the corporate model. Unfortunately, the majority of maximization algorithms available are very time consuming, and obtaining a reasonable portfolio mix becomes impractical. This paper overcomes this difficulty by using a very rapid optimization method from the chemical engineering profession called the Floppy Triangle. The paper includes an example of the use of this process to determine an optimal portfolio. It also discusses modifications of the algorithm that is required when the shorting of assets is not permitted.

Description: Mortality rates for a local community are desired in conjunction with the calculation of health-adjusted life expectancy HALE, an indicator of population health.

Description: Equity-indexed annuities [EIAs] can be viewed as mutual funds wrapped around with various guarantees. A recent paper derived a closed form formula for pricing this dynamic guarantee if early withdrawal from the fund [before maturity] is not permitted. This paper studies the pricing of dynamic protection without a maturity date, i.e., the investor chooses the date to cash in the fund accumulation.

Description: In this paper the author shows that the aggregate claims distribution of a portfolio modeled by a mix of the individual and collective models can be obtained with a single recursion under some conditions. He discusses why the collective model is not necessarily an approximation of the individual model in the context of pension funds, for example. An application to a Swiss pension fund is presented. From Actuarial Research Clearing House 2003, Vol. 1.

Description: A contingency table is a set of counts or frequencies obtained by classifying observations in two or more different ways. Log-linear analysis is applied to disability terminations, linking them to variables such as sex, age, region and maximum benefit period. Application to risk classification and underwriting are outlines.

Description: The author comments on the article Exposure Formulas Based on the Assumption of Uniform Distribution of Deaths written by T.N.E. Greville.

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