Development of Discrete Choice Model Considering the Budget Allocation Stage: Focusing on Multi-stage and Multi-category Cases with Outside goods

학위논문 (박사)-- 서울대학교 대학원 : 협동과정 기술경영·경제·정책전공, 2012. 8. 이종수.경제 발전으로 인해 기업들은 시장에 무수히 많은 제품 및 서비스들을 시장에 출시하고, 제품 간의 경쟁을 통해 극소수의 제품 및 서비스만 살아남아 이윤을 내고 있다. 또한 지속적인 국가 발전을 위해 정부는 인프라 구축 및 기술개발 로드맵을 수립하고, 친환경 제품들의 확산을 지원하는 등 다양한 활동을 하고 있으나, 일부 정책만이 그 효과를 내고 있다. 이와 같이, 새로운 제품이나 정책에 대한 소비자들의 반응을 사전에 알 수 없는 시장의 불확실성으로 인해서 기업 및 정부는 효과적인 제품 계획 및 정책 제안하는데 한계가 있다. 따라서 시장 불확실성을 줄이기 위해 소비자 구매 행태 연구는 경영 전략 및 정책 방향 수립 관점에서 필수적이다. 다양한 제품 및 서비스에 대한 소비자 구매 행태 연구는 IT, 마케팅, 에너지 및 환경 분야 등 여러 분야에서 수행되어 왔다. 또한 소비자 구매 행태 연구를 위해 다양한 모형들이 개발되고 사용되어 왔고, 그 중 이산 선택 모형은 소비자 선호 분석에 유용한 방법론의 하나로써 단일 선택 모형, 복수 선택 모형, 소비자 이질성을 반영한 모형 등 다양하게 개발되어 왔다. 하지만, 기존의 대부분의 모형들은 단일 품목에만 관심을 가지고 분석하고, 다른 품목의 상품들에 대한 가격과 특징에 대해서는 무관심 하였다. 경제학적으로 다른 품목을 선택모형에 고려해야 현실적인 가격 정책 및 소비자 선호를 분석할 수 있다. 또한 소비자들은 단순 선택 상황을 제외하고는 1단계 이상의 의사결정 과정을 거치므로, 소비자 의사결정 단계를 고려한 선택 모형 개발이 필요하다. 이러한 점에서 소비자들의 의사결정 구조와 다른 품목을 고려한 새로운 선택 모형 개발이 필요하다. 이 때, 수요 분석 및 예측 모형에 다른 품목을 고려하는 것은 소비자 관점에서는 소득 배분 단계를 소비자들의 의사결정 단계에 고려하는 것과 유사하다. 따라서 본 논문에서는 다른 품목과 소비자들의 의사결정 단계를 고려하기 위해 소득 배분 단계를 선택 모형에 고려한 모형 개발을 목적으로 한다. 본 논문에서 제안된 모형은 관심 품목에 속하는 제품의 가격 및 속성 수준에 대한 소비자 선호 분석과 더불어 다른 품목의 예산 구조가 관심 품목에 속하는 제품의 선택에 미치는 영향 등 포괄적인 분석이 가능하다. 본 논문에서 제안된 선택 모형은 소득 배분 단계와 제품 선택 단계를 고려한 모형과 소득 배분 단계와 제품 선택 및 사용 단계를 고려한 모형으로 구분된다. 두 가지 모형을 이용하여 본 논문에서는 ICT, 가정용품, 자동차 분야의 대표 제품들에 대한 실증분석을 수행한다. 첫 번째 실증연구는 스마트 기기의 등장으로 인해 소비자들의 소비 패턴에 많은 영향을 끼치고 있는 점을 고려하여 스마트 기기 선택에 대한 수요 분석을 소득 배분 단계를 고려하여 분석한다. 두 번째 실증연구는 녹색 발전을 위해 널리 확산되어야 할 친환경 제품의 선택에 대한 수요 분석을 소득 배분 단계를 고려하여 분석한다. 세 번째 실증연구는 차세대 스마트 자동차 제품 선택 및 사용을 고려한 수요 분석을 소득 배분 단계를 고려하여 분석한다. 세 가지 실증연구들을 통하여 본 논문에서 제안된 다양한 모형들의 활용성과 도출 가능한 함의들을 살펴본다. 결과적으로 본 논문에서 제안된 모형을 바탕으로 관심 품목과 다른 품목들 간의 소득 배분 변화가 관심 품목에 속하는 재화 선택과 사용에 미치는 영향을 종합적으로 분석함으로써 좀 더 정교한 소비자 구매 행태 분석이 가능하게 된다. 이를 바탕으로 정확한 제품의 수요 예측과 제품의 가격 정책 등의 정책적 제안을 하기 위한 유용한 정보를 제공할 것으로 기대된다. 또한, 본 논문에서 제안된 모형은 소비자 의사결정 구조 분석에 대한 방법론적 함의를 제공할 수 있을 것으로 생각된다.Due to—and in pursuit of—economic growth in the market, firms tend to release a variety of products and services onto the market. With competition occurring among these products, only a few of them survive and actually make a profit. In addition, while government performs various activities—such as constructing infrastructure, establishing a technology development roadmap, and supporting the diffusion of eco-friendly products, in order to pursue sustainable national development—few of its policies have had a lasting effect on the market. Thus, firms and government each bear limitations in being able to suggest effective product plans and policies, given that market uncertainty means that consumer preferences vis-à-vis new products or policies cannot be predicted in advance. Therefore, to reduce market uncertainty, research on purchasing behavior is essential to understanding the perspectives inherent in establishing management strategy and policy direction. Research on consumer purchasing behavior towards various products and services has been conducted in a variety of fields, such as the information technology (IT), marketing, energy, and environmental industries, among others. Additionally, various models have been developed and applied to analyze consumer purchasing behavior. Among these various methodologies, the discrete choice model—one of the more effective methods used to estimate consumer preference—has been developed in a diversity of ways, including the single choice model, the multiple choice model, and the choice model with heterogeneity. However, most of the previous models have focused only on inside goods, and do not consider product prices or attributes in other categories (i.e., outside goods). Economically, outside goods are included in a choice model, to analyze realistic price policy and consumer preference. Moreover, because a consumers decision-making process contains more than one stage—save for those related to the simplest of decision-making—choice models that consider multiple stages of the consumer decision-making process need to be developed. From these points, it is clear that the development of a new choice model that considers both outside goods and structure with regard to a consumers decision-making process is needed. The issue of considering outside goods within a choice model of demand analysis converges into cases that consider the budget allocation stage of a consumers decision-making process, from an individual-level perspective. Therefore, the purpose of this dissertation is to develop a choice model that includes the budget allocation stage, in order to consider both outside goods and the consumers decision-making stage. The proposed model in this dissertation can be used to undertake comprehensive analysis vis-à-vis the impact of the budget structure of outside goods on the product choice of inside goodsit can also be used in the general analysis of consumer preference vis-à-vis product prices and the attributes of inside goods. The proposed choice models in this dissertation are classified into two cases: one consists of the budget allocation and product choice stages, and the other of the budget allocation, product choice, and product usage stages. Based on these two proposed model types, this dissertation conducts empirical research on representative products from the information communication and technology (ICT), household products, and automobile industries. In the first empirical study, because consumer consumption patterns have been influenced in many ways by the introduction of smart devices, consumer purchasing behavior with regard to smart devices is analyzed by considering the budget allocation stage. In the second empirical study, demand analysis with regard to choices in eco-friendly products—with the endpoint of promoting green growth—is conducted by using a choice model with considering the budget allocation stage. In the third empirical study of this dissertation, consumer preference with regard to product choice and usage for smart cars—a next-generation automobile—is analyzed by considering the budget allocation stage. Through the three empirical studies, the utilization of the proposed models and the implications that derive from proposed models are examined. In conclusion, based on the proposed models in this dissertation, it is possible to analyze consumer purchasing behavior more accurately by comprehensively analyzing the impact of changes in the allocated budget between inside goods and outside goods on product choice and usage of inside goods. Moreover, the estimation results from the proposed model are expected to provide useful information that can be used to perform accurate demand forecasting vis-à-vis new products, and establish policy suggestions. Additionally, the proposed models are also expected to bear methodological implications with regard to analysis of the consumer decision-making process.Chapter 1. Introduction 1 1.1 Research Background 1 1.1.1 Standard Choice Model for Analyzing Consumer Purchasing Behavior 1 1.1.2 Budget Allocation (Inside goods v.s. Outside goods) Stage in the Choice Model 5 1.2 Research Motivation and Objectives 8 Chapter 2. Previous Literature 16 2.1 Choice Models with a Single/Multi-stage Model 17 2.1.1 Single-stage Model 17 2.1.2 Multi-stage Model 25 2.2 Choice Models with a Single/Multi-category Model 33 2.2.1 Single-category Model 34 2.2.2 Multi-category Model 42 2.3 Limitation and Recent Issues considering the Budget Allocation Stage in the Choice Model 45 Chapter 3. Models 50 3.1 Research Subjects 51 3.2 Multi-stage and Multi-category Discrete-continuous Choice Model with Outside goods 56 3.2.1 Previous Model: Multi-stage and Single-category Model 56 3.2.2 Proposed Model 60 3.2.3 Identification Issue and Estimation Method 73 3.2.4 Validation of Proposed Models 84 3.2.5 Implications of Proposed Models 95 Chapter 4. Empirical Study 98 4.1 Multi-stage and Multi-category Discrete Choice Model with Outside goods in ICT 99 4.1.1 Introduction 99 4.1.2 Data and Empirical Model 101 4.1.3 Results and Discussion 106 4.2 Multi-stage and Multi-category Discrete Choice Model with Outside goods in Household Products 120 4.2.1 Introduction 120 4.2.2 Data and Empirical Model 122 4.2.3 Results and Discussion 126 4.3 Multi-stage and Multi-category Discrete-continuous Choice Model with Outside goods in Automobiles 138 4.3.1 Introduction 138 4.3.2 Data and Empirical Model 141 4.3.3 Results and Discussion 146 Chapter 5. Summary and Conclusion 158 Bibliography 164 Appendix A: Conditional Multivariate Normal Distribution 183 Appendix B: The Results of the Simulation Study 185 Abstract (Korean) 191Docto

A case of a cutaneous angiomyolipoma

A cutaneous angiomyolipoma, which is also known as a cutaneous angiolipoleiomyoma, is a rare benign mesenchymal tumor. Only 18 cases have been reported in the English literature. We describe a case of an angiomyolipoma presenting on the right ear helix of a 26-year-old female. The histopathologic examination revealed a typical form of an angiomyolipoma with a proliferation of mature adipocytes. As with all previously reported cases, our patient did not present with the stigmata of tuberous sclerosis. This is the 20th reported case of cutaneous angiomyolipoma and the 3rd reported case in Koreaope

Study of impact factors upon health care expenditure by household

보건행정학과/석사[한글]경제수준의 향상은 건강에 대한 관심과 건강 수준의 향상을 불러일으켰다. 이와 같은 건강 수준의 향상을 위한 비용이기도 하지만, 그동안 의료비는 비약적으로 증가하였다. 2000년 GDP의 4.8%(27.6조원)이던 국민의료비가 2005년에는 5.9% (48.1조원)에 이르렀다.본 연구는 이와 같이 급증하고 있는 의료비 지출에 어떠한 요인들이 영향을 주고 있는지를 파악하고, 더 나아가 이러한 결과를 활용할 방안을 모색하는데 주요한 목적을 두고 있다. 특히, 여기에서는 가계에서 이루어지는 가계본인부담 지출에 중점을 두어 실증분석을 하고자 한다.실증분석 대상으로는 2005년 가계조사 자료를 사용하였으며, 보건의료비를 보건의료서비스에 대한 비용, 의약품에 대한 비용, 보건의료용품기구에 대한 비용으로 나누어 세부적으로 살펴보았다.연구 결과에 의하면, 가계에서 이루어지는 보건의료비 지출은 ‘소비지출규모’, ‘가구원수’, ‘가구유형’, ‘가구주의 교육수준’의 유의한 영향을 받는 것으로 나타났다. 주요 연구 결과는 다음과 같다.첫째, ‘소비지출규모’가 증가할수록 보건의료서비스 비용, 의약품비, 보건의료용품기구 비용은 유의하게 증가하였다.둘째, ‘가구원수’는 비목별로 약간의 차이는 있었지만, 전반적으로 집단 간 유의한 차이를 보였다. 의약품비는 2인 가구가 높은 지출을 보였고, 보건의료용품기구 비용은 3인 가구 이상의 나머지 집단 모두가 2인 가구에 비해 높은 지출을 보였다. 보건의료서비스 비용은 6인 이상 가구가 높은 지출을 하는 것으로 나타났다.셋째, ‘가구유형’의 경우, 노인가구가 모든 비목에서 일반가구보다 지출이 높았으며, 반대로 모자가구는 보건의료서비스 비용과 의약품비의 지출이 낮았다.넷째, ‘가구주의 교육수준’의 경우, 고등 교육을 받을수록 의약품비와 보건의료서비스 비용의 지출은 감소하였고, 보건의료용품기구 비용의 지출은 증가하였다.이와 같은 결과는 개별 가계의 의료비 지출 행동을 설명하는데 사용할 수 있을 뿐만 아니라, 더 나아가 국민보건계정을 구축하는데도 활용할 수 있다. 본 연구에서 분석 대상으로 한 가계조사 데이터는 우리나라의 의료비 규모를 산출하는 보건계정 작업의 기초자료이기도 하기 때문이다.따라서 본 연구를 통해 밝혀진 가구원수와 같은 영향 요인들을 최대한 반영한다면 국민보건계정 구축 및 국민의료비 추계의 정확성을 더욱 높일 수 있을 것으로 기대된다. [영문]With stronger economic growth, the public's interest in the health care system increases as well as health care expenditures. Total health expenditure as a share of GDP was 4.8% in 2000, and 5.9% in 2005, an increase of 1.1%.The main objective of this study is to examine impact factors upon health care expenditures which have sharply increased. Particularly, this study focuses on out-of-pocket payments per household.For the empirical analysis, data from the Household Income and Expenditure Survey (HIES) conducted in 2005 was used. Health care expenditures are divided into three detailed components: expenditure of medical services, expenditure of drugs, and the expenditure of medical supplies and devices.The empirical results show that household health care expenditures are significantly related to household expenditure, family size, type of household, and the level of household occupants' education.First, household expenditure was significant for all detailed components, where its effect was positive.Second, there was little difference between the detailed components; medical services, drugs and medical supply expenditures, but the component that showed great significance was family size. Families that consist of 2 family members spent more on drugs than households consisting of more then 3 members. In contrast, other households with 3 or more family members spent more on medical supplies and devices than those with 2 members. Households with 6 family members spent more on medical services than those with 2 members.Third, elderly households, with members aged 65 years and older, spent more money in all instances of health care. Single mother households spent less money on medical services and drugs.Fourth, higher levels of education were negative for the expenditure of medical services and drugs, but positive for the expenditure of medical supplies and devices.Based on the above findings, this analysis would contribute not only to explain the household's behavioral patterns but also to show the importance of constructing National Health Accounts. Household Income and Expenditure Survey data which used for the empirical analysis of this study must be the baseline data for constructing National Health Accounts.This study's results have shown the correlation between family size and health care expenditures, and to consider these factors when modifying National Health Accounts.ope

Atopic dermatitis and skin barrier dysfunction

Atopic dermatitis is a chronic relapsing eczematous dermatosis, which usually starts in childhood, and various causes are intricately associated with the development of the disease. Recently, various abnormalities in barrier function have been identified as the cause of atopic dermatitis. Loss-of-function mutation of filaggrin, a significant constituent of skin barrier, has been revealed as a cause for atopic dermatitis, and factors like enhanced protease activity, and decreased synthesis of the lipid lamellae especially ceramides also plays an important role in barrier dysfunction. Not only these genetic causes but also environmental factors are associated in barrier dysfunction, such as soap or detergents which increases skin pH, or proteases of dust mites or cockroaches which enhances epidermal barrier breakdown. Lately, skin barrier dysfunction is also thought to play an important role in the early stage of other allergic diseases such as asthma. Therefore, comprehension of the function of skin barrier can provide help in understanding various allergic diseases.ope

Reactivation of anti-human alpha-enolase antibody-positive Behçet's disease by carbon dioxide laser treatment.

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A Case of Netherton Syndrome Responsive to 1% Topical Pimecrolimus Cream

Netherton syndrome is a rare autosomal recessive disorder associated with mutation of the SPINK5 gene. Its typical manifestations are the triad of ichthyosis, hair shaft abnormality, and atopic diathesis. We report a case of Netherton syndrome and suggest topical pimecrolimus as a well-tolerated agent for truncal lesions. A 17-year-old male patient presented with skin lesions involving the whole body and hair present shortly after his birth. On physical examination, there were polycyclic serpiginous patches with peripheral scales on the extremities (Fig. 1A, 1B). Erythematous lesions resembling atopic dermatitis were present on the popliteal fossa area; however, they were mild and without lichenification. Also, diffuse erythema was noted on the face with a positive Hertoghe sign and brittle hair (Fig. 1C). Clinically, the lesions with geographic, sharply defined erythema on the trunk were compatible with ichthyosis linearis circumflexa (ILC). Pathological findings revealed hyperkeratosis, acanthosis, and parakeratosis along with perivascular cellular infiltration, mostly lymphocytic, in the upper dermis (Fig. 2A). Also, a closer inspection of the patient’s hair with light microscopy and scanning electromicrography yielded findings suspicious for trichorrhexis invaginata (Fig. 2B). Complete blood count and routine blood chemistry were all within normal limits; however, total IgE was elevated (3,449 IU/mL) and allergen-specific IgE to Dermatophagoides farinae was strongly positive (class 6) on ImmunoCAP®. The combination of ichthyosis, hair shaft abnormality, and atopic tendency satisfied the diagnostic triad of Netherton syndrome. For treatment, 1% topical pimecrolimus ointment was applied once daily for 6 months. No adverse events occurred, and the most prominent changes occurred over the extremities with a reduction of scaly hyperkeratotic plaques (Fig. 1D, 1E). However, the facial erythema persisted despite the applica tion of pimecrolimus. There was an approximately ＞50% reduction of the Netherton Area and Severity Assessment score from the initial value. There is no set guideline for the treatment of Netherton syndrome. Topical steroid, topical pimecrolimus, tacrolimus, calcipotriene, 12% ammonium lactate, systemic retinoid, and NB-UVB are some of the options available. Among these treatments, pimecrolimus has been suggested as an effective choice for ILC1. Treatment with pimecrolimus for 18 months caused a dramatic reduction in disease severity and pruritus score compared with baseline2. Also, despite concerns of decreased protease inhibition within the epidermis and defective barrier function increasing the risk of transepidermal water loss, skin infection, and, most important, systemic absorption of topical drugs3, treatment of 99% of the body surface area with pimecrolimus did not result in its increased level in blood, assuring its relative safety4. The atopic dermatitis on flexural sites and ichthyosis on the trunk and extremities in our patient showed improvement after treatment with pimecrolimus. However, no effect on facial erythema was seen. Diffuse erythema on the face is commonly noted in Netherton syndrome. Yet, it is still unclear whether the major contributory factors for persistent erythema are a result of an ineffective barrier, vasculature abnormality, or environmental effects. We report an educational case reminding of the classical triad of Netherton syndrome and showing the effectiveness of topical pimecrolimus. Our patient showed comparable results to those reported in Western countries; however, we additionally suggest the need for future studies aimed at uncovering the mechanism of facial erythema refractory to treatment.ope

The Clinical Efficacy of Azathioprine in Korean Patients with Atopic Dermatitis

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Efficacy of Biodegradable Microneedle Patches on Periorbital Wrinkles

BACKGROUND: Biodegradable microneedle technology is a recently developed method to deliver medical and pharmaceutical medications into the skin, and is expected to yield better treatment results than topical application methods. OBJECTIVE: To evaluate the efficacy of hyaluronic acid (HA)-based microneedle patches and epidermal growth factor (EGF)-containing microneedle patches on periorbital wrinkle improvement. METHODS: A 20-week randomized, double-blind study was performed. Twenty-five Korean patients with periorbital wrinkles and a wrinkle severity rating scale (WSRS) score above 2 were enrolled into the study. The patients completed the study using the two different types of patches on each side of the designated periorbital wrinkles area every other day for 8 weeks. Patients were requested for an additional 12-week follow up. Wrinkle improvements were assessed by WSRS score, subjective patient satisfaction score, and imaging analysis using the visiometer, corneometer, cutometer, and mexameter, respectively (Courage&Khazaka, Cologne, Germany). RESULTS: Both the HA-based microneedle patch and EGF-containing HA-based microneedle patch had positive effects on WSRS score, patient satisfaction levels, and corneometer result with statistically significant differences. No significant side effects were noticed. CONCLUSION: With respect to efficacy, no statistical difference between the two groups were noted, indicating that the anti-wrinkle effects of the microneedle patch may solely be due to the HA rather than the EGF.ope

Clinical Efficacy and Safety of Naltrexone Combination Therapy in Older Patients with Severe Pruritus

BACKGROUND: Severe pruritus is a challenging condition, and it is more difficult to deal with in older patients due to their limitations in taking oral medication because of underlying diseases, possible interaction with concurrent medications, and poor general condition. OBJECTIVE: We evaluated the efficacy and safety of naltrexone (Revia®), an opioid antagonist, in elderly patients with severe pruritus that was not easily controlled with conventional antipruritics. METHODS: Eighteen patients were enrolled, with a mean age of 73 years. They additionally received 50 mg of naltrexone per day for an average of 2 months. RESULTS: Using the visual analogue scale, 13 (72.2%) of 18 patients showed a "much improved" condition, reporting more than a 50% decrease in pruritus intensity. Sixteen (88.9%) showed symptomatic improvement, and only 2 (11.1%) had persistent pruritus. Five patients reported side effects including insomnia, fatigue, constipation, and anorexia. However, reactions were either limited to the first 2 weeks or well managed. CONCLUSION: Naltrexone could be an effective and safe alternative treatment option to control severe pruritus in older patients.ope

Lupus miliaris disseminatus faciei without facial involvement.

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