• The Korean Journal of Applied Statistics
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• v.24 no.5
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• pp.769-789
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• 2011

The life table is a statistical model for life expectancy and reflects mortality experiences exposed to a particular group of people. The following three issues are prerequisite for constructing the life table : a selection of how to estimate the death probability from observed death rates, a graduation method to smooth irregularity of the death probabilities, and an extension method of the death probabilities for oldest-old ages. To construct the life table that is fittest to Korean mortality experiences, we examine five estimation methods such as Chiang's and Greville's for the death probability, three graduation techniques including Beer's and Greville's formulae, and twelve mathematical functions for the extension of death probabilities for oldest-old ages. We also propose a method to resolve the cross-over problem arising from construction the life table.

• Korea journal of population studies
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• v.24 no.1
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• pp.67-90
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• 2001

Korea National Statistical Office(KNSO) estimated period birth rates, period death rates, and probability of dying for infant(q$q_{0}$) at period life table, considering the unregistered infant deaths. As Ministry of Health and Welfare(MHW) conducted 1993 and 1996 birth cohort infant death surveys. KNSO re-estimated infant mortality levels(especially q$q_{0}$). For the re-estimation, reference data were derived from death registration. MHW surveys, death registration of developed countries. Model Life Tables, and Life Table for Japan. Seventeen simulations were made by the combination of estimation methods and reference data. The final $q_{0}$ was estimated based on the relationship between $q_{0}$ of MHW 1993 survey and $q_{1-4}$ of registered deaths for the period of 1971~1997. For 1993, $q_{0}$ was calculated directly from the 1993 MHW survey and interpolation and extrapolation were made for 1995 and 1997 using the relative decrease rates of $q_{0}$ between 1993 and 1996 MHW surveys. Utilizing the formular of Coale-Demeny North Model, $q_{0}$ was transformed into $m_{0}$ for the period 1971~1997. Finally, cremation data are found to be very useful for the estimation of 1998 infant mortality level by supplementing unregistered infant deaths, especially neonatal deaths. Furthermore, they are found to be very useful to produce fetal and perinatal death statistics.

• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.49-57
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• 2005

This study developed a methodology for estimating the fatality reduction by introducing technical regulation on pedestrian protection in pedestrian-vehicle collisions. Modeling a probabilistic pedestrian fatality model with logistic regression approach was one of keen interests, which employed in estimating the fatality reduction. Collision speed obtained from the accident reconstruction was used in the model development. The effects of fatality reduction, in case various Head Injury Criterion (HIC) and collision speeds are applied for the regulation. were presented as the major outcome of this study. It is expected that the outcome of this study would be an invaluable tool to assist in developing various technologies and policies for pedestrian protection.

• Environmental and Resource Economics Review
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• v.16 no.3
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• pp.683-699
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• 2007

This study applied the choice experiment (CE) method to measure values of statistical lives from multi-attributed mortality risk reduction choices. The four characteristics of mortality risk (i.e. cause of death, voluntariness of mortality risk, timing of death, magnitude of mortality risk reduction) are utilized to design the alternatives of choice sets. The estimation results for the multinomial logit model show that individuals are willing to pay 27,930 won per year for a change from the status quo to a $\frac{1}{100}$ mortality risk reduction for 10 years, 116,773 won per year for mortality risk reduction associated with adults, 97,682 won per year for voluntary mortality risk reduction, 77,234 won per year for involuntary mortality risk reduction. There were several estimates of VSL related to different attributes of mortality risk. The mean VSLs of infant/child/young adult ranged from 1,165 million won to 1,367 million won. The mean VSLs ranged from 1,631 million won to 1,833 million won for adult, and were between 1,128 million won and 1,330 million won for old person.

• Environmental and Resource Economics Review
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• v.32 no.1
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• pp.1-26
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• 2023

This study employs the dichotomous choice contingent valuation method to estimate the Value of a Statistical Life (VSL) and the Value per Statistical Case (VSCC) of cancer risk. In contrast to the previous studies, which presented the mortality risk probability directly, the study uses conditional probability, which combines the chance of getting cancer and dying from it. In addition, the study examines the impact of variables that may affect willingness to pay for reducing the risk of death from cancer and getting cancer, such as the impact on daily life and pain levels associated with cancer. The results indicate that the estimated cancer VSL ranges from approximately 952 million won to 3.359 billion won, while the VSCC is estimated to be between about 0.42 billion won and 2.72 billion won. The study finds a significant difference in the VSL depending on whether the reduction in mortality risk is from a decrease in the chance of getting cancer or a decrease in the chance of dying from cancer. However, the effect of impacts on daily activities and pain on willingness to pay is inconclusive.

• The Korean Journal of Applied Statistics
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• v.28 no.3
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• pp.393-406
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• 2015

We examine how to model mortality risk using the adaptation of the mean-reverting processes for the two factor model proposed by Cairns et al. (2006b). Mortality improvements have been recently observed in some countries such as United Kingdom; therefore, we assume long-run mortality converges towards a trend at some unknown time and the mean-reverting processes could therefore be an appropriate stochastic model. We estimate the parameters of the two-factor model incorporated with mean-reverting processes by a Metropolis-Hastings algorithm to fit United Kingdom mortality data from 1991 to 2015. We forecast the evolution of the mortality from 2014 to 2040 based on the estimation results in order to evaluate the issue price of a longevity bond of 25 years maturity. As an application, we propose a method to quantify the speed of mortality improvement by the average mean reverting times of the processes.

• Environmental and Resource Economics Review
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• v.17 no.4
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• pp.845-873
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• 2008

This study estimates the VSL(value of a statistical life) as well as the WTP(willingness to pay) for mortality risk reduction using sample selection model with data on liver cancer examination which is associated with little possibility of multi-purpose(i.e. joint production) in averting behavior. The marginal benefits of mortality risk reduction are estimated by applying for household production function model with medical expense and the time required for medical examination of liver cancer. Individuals are more likely to take liver cancer test if they are male, older, higher educated, those with spouse, smoker, more income of household, and more anxious about their health. The costs of liver cancer examination are statistically significantly affected with expected signs by size of mortality risk reduction, sex, period of eduction, those with spouse, and household income. The marginal effect of mortality risk reduction owing to taking liver cancer examination is estimated at 321,097 won. The costs of liver cancer examination are increased by 905 won with more one year of education period and by 1,743 won with more one million won in household income. On liver cancer examination, male spends more 12,310 won than female and those with spouse pay more 7,969 won than those without spouse. Therefore the VSL from mortality risk reduction due to liver cancer examination is 321.10 million won at mean size of mortality risk reduction and mean cost of liver cancer examination. The results of sensitivity tests on costs and effects of liver cancer test shows that the VSLs are estimated in a range from 160.55 million won to 642.19 million won.

• The Korean Journal of Applied Statistics
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• v.37 no.2
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• pp.225-237
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• 2024

In the analysis of competing risks data, some of covariates may not be fully observed for some subjects. In such cases, excluding subjects with missing covariate values from the analysis may result in biased estimates and loss of efficiency. In this paper, we studied multiple imputation and the augmented inverse probability weighting method for regression parameter estimation in the cause-specific proportional hazards model with missing covariates. The performance of estimators obtained from multiple imputation and the augmented inverse probability weighting method is evaluated by simulation studies, which show that those methods perform well. Multiple imputation and the augmented inverse probability weighting method were applied to investigate significant risk factors for the risk of death from breast cancer and from other causes for breast cancer data with missing values for tumor size obtained from the Prostate, Lung, Colorectal, and Ovarian Cancer Screen Trial Study. Under the cause-specific proportional hazards model, the methods show that race, marital status, stage, grade, and tumor size are significant risk factors for breast cancer mortality, and stage has the greatest effect on increasing the risk of breast cancer death. Age at diagnosis and tumor size have significant effects on increasing the risk of other-cause death.

• The Korean Journal of Applied Statistics
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• v.28 no.4
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• pp.703-719
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• 2015

We propose an extension of the Lee and Jho (2015) mean reverting the two factor mortality model by incorporating a period-specific cohort effect. We found that the consideration of cohort effect improves the mortality fit of Korea male data above age 65. Parameters are estimated by the weighted least squares method and Metropolis algorithm. We also emphasize that the cohort effect is necessary to choose the base survival index to calculate longevity bond issue price. A key contribution of the article is the proposal and development of a method to calculate the longevity bond price to hedge the longevity risk exposed to Korea National Pension Services.

• The Korean Journal of Applied Statistics
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• v.27 no.2
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• pp.211-226
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• 2014

This paper discusses life expectancy differentials of beneficiaries of national pension old-age benefit and benefit-cost analysis in Korea. These results are useful indicators for the assessment of retirement income security of beneficiaries and old-age benefits. This paper analyzes benefit-cost ratio, internal rate of return and generation transfer amount, using life tables by lifetime incomes. The result of the actuarial analysis for male life expectancy is approximately 21.69 to 24.63 years. The result of the actuarial analysis for female life expectancy is approximately 27.63 to 29.81 years. The result of the actuarial analysis of low income level is that the benefit-cost ratio is lower approximately 2.68 to 4.83%, the internal rate of return lower approximately 0.00 to 0.74%, the generation transfer amount lower approximately 3.00 to 5.74%, than total income level. The result of the actuarial analysis of high income level is that the benefit-cost ratio is higher approximately 2.07 to 4.98%, the internal rate of return higher approximately 0.03 to 1.73%, the generation transfer amount higher approximately 2.53 to 9.68%, than the total income level. The results by income varies due to the effect of income redistribution and life expectancy on the national pension.