• Title/Summary/Keyword: 이중차분분석

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Analysis of Tidal Effects on Network-based GPS Positioning (조석영향에 의한 망기반 GPS 측위 변화 분석)

  • Yoon, Ha-Su;Hong, Chang-Ki;Kwon, Jay-Hyoun;Choi, Yun-Soo
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.31-34
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    • 2010
  • The rover positioning is performed by estimating the baseline vector components in doubledifference positioning mode. This means that relative displacement due to the tide effects can be neglected when the distance between the reference and rover station is relatively short. However, the tide effects should be carefully modeled and removed as the baseline length gets longer. In this study, the relative displacement over the Korean Peninsula due to tide effects are examined through the numerical analysis. The results show that the tide modeling is required for the precise GPS positioning at cm-level accuracy.

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The Effects of The Minimum Wage On Working Poor's Poverty-Exit Possibility (최저임금이 근로빈곤 탈출에 미치는 효과)

  • Lee, Sikyoon
    • Korean Journal of Labor Studies
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    • v.19 no.1
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    • pp.35-64
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    • 2013
  • This paper explores whether or not a minimum wage increase can do much to alleviate working poor. For this purpose, I analyze transitions from working poor to working non-poor and to unemployment or non-economically active states, using KLIPS (Korea Labor and Income Panel Study). This study uses the multilevel multinomial logit model to control unobserved individual heterogenous characteristics. It finds that a minimum wage increase tends to cause a higher probability of transitions from working poor to working non-poor. It is also discovered that a minimum wage increase is not negatively related with the persistence of the working state. It is concluded that minimum wage increases are likely to be effective in improving the living standards of the 'working poor'.

The Impact of Attracting University Campuses on the Local Economies of Small and Medium-Sized Cities - Focusing on Changes in Neighborhood Commercial Areas - (지방 중소도시 내 대학캠퍼스 유치가 지역경제에 미치는 영향 -근린상권 변화를 중심으로-)

  • Lee, Dong Yun;Jeong, Seok
    • Journal of the Korean Regional Science Association
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    • v.40 no.2
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    • pp.3-19
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    • 2024
  • The purpose of this study is to analyze the impact of attracting a university campus on the local economies of small and medium-sized cities, focusing on changes in local commercial neighborhoods(such as the number of startups, closures, and stores counts). For this study, a Difference-in-Difference(DID) analysis was used to compare the period before and after the attraction of university campuses in four local small and medium-sized cities. These include the Yangsan Campus of Pusan National University, the Jincheon Campus of Woosuk University, the Taean Campus of Hanseo University, and the Dangjin Campus of Hoseo University. The comparison was based on the number of startups, closures, and store counts, using local data provided by the Ministry of the Interior and Safety. The main findings of the study are as follows. First, attracting a university campus has a positive impact on the number of startups, both spatially and temporally. The spatial factors for the number of closures and stores showed a decrease, while the interaction terms representing the period before and after attracting the university campus all indicated an increase. Second, the number of startups in cultural and food-related sectors increase, reflecting the new demand created by attracting the university campus. However, there was also an increase in the number of closures, indicating rapidly changing consumption trends among university students. Third, physical environmental factors such as the number of building floors, land use zoning, and officially assessed land prices have a significant impact on the number of startups, closures, and stores. This supports the assertion that attracting university campus have a positive impact on the revitalization of local commercial neighborhoods.

Analysis of the Impact of Investment in National Fishing Ports on Fishery Income Opportunities Using the Propensity Score Matching Difference-in-difference Method (국가어항 투자의 어업소득 기회 영향 분석: 성향점수매칭 이중차분법을 이용하여)

  • Kim, Bong-Tae
    • The Journal of Fisheries Business Administration
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    • v.53 no.3
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    • pp.85-101
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    • 2022
  • This study analyzed the performance of the national fishing port development project, which lacked ex-post impact evaluation despite a lot of investment in terms of fishery income opportunities. Using micro data from the Census of Agriculture, Forestry, and Fisheries, the sales amount of fishery products and the proportion of fishery-related businesses were used as performance indicators. The fishery households in the fishing port area (treatment group) and those not in the area (control group) were classified through data pre-processing, and factors unrelated to the fishing ports were controlled using the propensity score matching difference-in-difference method. The analysis target is six fishing ports with large investment in from 2010 to 2014. As a result of the analysis, it was confirmed that the sales of fishery products increased significantly in four of the six fishing ports, and the proportion of fishery-related businesses increased in two fishing ports. The analysis method of this study can be fully utilized in the evaluation of the Fishing Community New Deal 300 Project, which is in need of performance analysis.

An Empirical Analysis on the Production and Price Effect by Agricultural Disaster Insurance (농업재해보험의 생산량 및 가격 효과에 관한 실증분석)

  • Han, Sungmin
    • KDI Journal of Economic Policy
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    • v.36 no.4
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    • pp.135-169
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    • 2014
  • This study empirically analyzes changes in production patterns of farmers by agricultural disaster insurance. The aim of this project is to achieve stability of farm management by paying insurance in case of a natural disaster. However, it causes farmers to change production patterns in the direction of increasing production, and leads the crop price to drop. This can be explained by producers' risk reduction through the disaster insurance. The empirical analysis is based on IV approach with using two stage least squares method. The first stage estimates by difference-in-differences methodology indicate that the production of insurable crops increases more about 80,000ton on average than that of non-insurable crops. In addition, to solve the endogeneity problem caused by general supply and demand model, I use the first stage estimates and find that the price index of the crops drops about 2.3% according to the production increase by 10,000ton. The credibility of these results is also attained by various robustness checks. These findings suggest that it is necessary for government to analyze the whole economy which consists of producer and consumer welfare when it determines the policy. Besides, it implies that it is essential to develop a new market to cope with the unintended effect.

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Ownership Structure and Performances: An Analysis of Cooperatives and Investor-Owned Utilities in the U.S. Electric Power Industry (미국 전력산업에서 기업의 소유권 형태에 따른 운영성과의 차이 분석)

  • Jang, Heesun
    • Environmental and Resource Economics Review
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    • v.27 no.1
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    • pp.161-194
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    • 2018
  • This study examines performances of cooperatives relative to investor-owned firms in the US electric power industry. Using a panel data of firms from 2001 to 2014, the results show that cooperatives operate under conditions of more difficult capital constraints associated with the higher cost of debt and limited access to external equity capital. While investor-owned utilities, especially the large utilities that are less capital constrained, take benefits from substantial scale economies existing in the industry, the marginal cost of operation substantially increases with output for cooperatives. I do not find differences in profitability between the two ownership structures, measured by return on assets and return on equity. Plant capacity utilization, which is a measure of plant efficiency conditional on the operation, is also not statistically different between the two groups.

Analysis of Disaster Reduction Effect of Industrial Disaster Prevention Financial Support Project: Focusing on Small Business Sites (산업재해 예방 재정지원 사업의 재해 감소 효과 분석: 소규모 사업장을 중심으로)

  • Choi, Hun;Park, Manhee
    • The Journal of the Korea Contents Association
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    • v.19 no.4
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    • pp.54-62
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    • 2019
  • With regard to industrial accidents, large corporations and public institutions are continuously reducing disasters through systematic management. However, industrial accidents continue to increase in small-scale workplaces. In order to ensure the safety of workers, the government supports the purchasing of industrial accident prevention equitments through financial support projects for small business. However, despite the financial support, the effectiveness of the project is hardly verified. In this study, we analyze the policy effectiveness of the financial support program for industrial accident prevention in a small-scale workplace using the difference-in-difference method. To achieve research purposes, we used the data on the occurrence of industrial accidents, the status of workplaces by year and the data on the status of workplace benefiting from financial support program for the past 10 years. This study is significant in that it analyzed the net effect of financial support programs for disaster reduction in the small business site.

An Empirical Analysis of the Private Tutoring Prohibition Policy and Class Mobility (사교육금지정책과 계급이동의 관계에 관한 실증분석)

  • Jang, Soomyung;Han, Chirok;Yeo, Eugene
    • 한국사회정책
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    • v.23 no.1
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    • pp.179-202
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    • 2016
  • This study analyses the effects of the major educational policies, focusing on the private tutoring prohibition policy(PTPP), on the intergenerational class mobility(ICM) by using Korea Labor and Income Panel Study(KLIPS) 1st-12th surveys. Because private tutoring(shadow education) can be effective for academic achievement of children of above middle classes that spend most private tutoring expenditure and have more information on education, the private tutoring prohibition policy can increase the intergenerational mobility. This study confirms this possibility. Even when the overlapping effect of the middle school equalization polity is controlled for, there is still high effect of the PTPP. We think that we still need to examine the level of intergenerational mobility with PTPP cohort with that of later cohorts in the future. We also emphasize the compositive effect of the several consistent policies such as middle school and high school equalization polices and the PTPP and length and continuity of the policies for the higher mobility.

Analysis on the Effect of the Urban Park Development on Change of Urban Spatial Structures - Focused on Gentrification around Seoul Forestry Park in Seongdong-gu - (도시공원 조성이 도시공간구조 변화에 미치는 영향 분석 - 성동구 서울숲 젠트리피케이션 현상을 중심으로 -)

  • Moon, Seung-Woon;Kim, Euijune;Ku, Jin-Hyuk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.45 no.2
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    • pp.76-88
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    • 2017
  • The urban park plays important roles in protecting the urban landscape and improving citizens' health, recreation, and the emotional life. Above and beyond these roles, the urban park is expected to rearrange urban spatial structures as a kind of urban system. The purpose of this paper is to identify empirically to change urban spatial structures by construction of the urban park. This study regards gentrification around the urban park as a process to change urban spatial structures. The gentrification means the regeneration and upgrading of deteriorated urban property by the middle class or commercial developers. The site of case analysis is the Seoul Forestry Park in Sungdong-gu, Seoul. The Seoul Forestry Park is regarded as a representative urban park of Seoul, and caused gentrification around park after the 2005 opening. This study operationally defines the gentrification index and the accessibility index from an urban park and offers an empirical analysis of relation among the urban park, the gentrification and urban spatial structure in a statistic district which is the minimum unit of Korean statistic data in 2000, 2005, and 2010, using Difference-in-Difference method and linear probability model. The results of this empirical study show that the Seoul Forestry Park changes urban spatial structures by gentrification. It reverses a trend of migration of gentrifiers before and after construction of the Seoul Forestry Park. It suggests urban park construction as an alternative method for urban regeneration by inducing the middle class into the inner city of Seoul.

The Impact of Internal Migration on Wage Growth among College Graduates (지역이동이 대졸자의 임금 변화에 미치는 영향)

  • Choi, Koangsung;Kang, Dongwoo;Cho, Chung
    • Journal of Labour Economics
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    • v.41 no.2
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    • pp.61-88
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    • 2018
  • This paper examines the impact of internal migration on wage growth among college graduates using Propensity Score Matching methods. We define migration as moving between Seoul Metropolitan Area (SMA) and non-SMA based on the locations of graduates' first and second jobs. We also take the direction of migration into account for examining the wage premium in SMA. In order to estimate the impact of migration on wage growth, we use the Graduate Occupational Mobility Survey (2010GOMS) coupled with other supplementary data such as College Scholastic Ability Test score and local characteristic variables. The results reveals that graduates moving from SMA to non-SMA do not experience significant wage growth. However, we find that graduates moving from non-SMA to SMA experience an increase in their monthly wage about 170,000~186,000 KRW on average (9.5~10.3% of their monthly wage on the first job).

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