## 3 Literature Review
### Study of the Causes of Housing Abandonment
[21] also categorized regional characteristics in terms of nationwide, urban, and rural areas and analyzed the impact of regional characteristics on housing abandonment. The result of the analysis revealed the following: in urban areas, housing abandonment was influenced by population, the ratio of older adults, the ratio of women of childbearing age, the building age, and accessibility; while in rural areas, housing abandonment was influenced by population variables, building age, and the number of businesses. In the nationwide area, a wide variety of factors contributed to housing abandonment. They concluded that the speculated determinants for housing abandonment greatly varied from one region to another. [PERSON] and [PERSON] [22] selected 258 submunicipal divisions in Jeonju Metropolitan City and in urban-rural complex areas in Jeoltanam-do and Jeollabuk-do provinces in Korea, and analyzed the variables of housing environment that affected housing abandonment in terms of economic, social, and environmental factors (i.e., safety, public sanitation, convenience, and comfort). The results of the analysis showed that housing abandonment was affected by the ratio of recipients of the National Basic Living Security Allowance, the ratio of the elderly population, and the ratio of houses older than 30 years. [PERSON] and [PERSON] [23] used the data from Statistics Korea and analyzed the variables of housing abandonment in the nationwide area, Seoul Metropolitan Area, five metropolitan cities, and provincial regions. They discovered that an increase in the new housing ratio and the old housing ratio was found to influence the housing abandonment in all areas. By contrast, an increase in the number of households and employees exerted the reverse impact on housing abandonment throughout the country. The housing sale price index had an impact only in the metropolitan area and in the five major metropolitan cities, while the increased ratio of the elderly population had an impact only in the provincial regions. Several scholars viewed physical and environmental factors as the main cause of housing abandonment. A well-known study conducted by [PERSON] et al. [24] examined the environmental and behavioral variables that affected housing abandonment in Newark, NJ, USA, and argued that the occurrence of housing abandonment was attributed to many social variables and some physical variables, such as building maintenance, the ratio of abandoned houses in the area, and the status of residence. [PERSON] et al. [25] asserted that the physical housing condition determines the likelihood of housing abandonment. [PERSON] [5] analyzed the impact of neighborhood condition on housing abandonment in Columbus and Youngstown, OH, USA, and argued that the characteristics of a neighborhood, such as physical condition, housing market, and gentrification, affected housing abandonment, with each characteristic having a different impact depending on the region. [PERSON] et al. [26] identified many cases of housing abandonment in an area with a large elderly population in Philadelphia, PA, USA, and asserted that the structure or the scale of houses and sites, physical and functional defects, and the location of houses impacted housing abandonment. [PERSON] et al. [7] analyzed the effect of neighborhood variables on housing abandonment in 16 districts in Busan, Korea. The results of the analysis revealed that housing abandonment was more likely to occur in areas with a low-density general population and a high-density elderly population, and that were far from major commercial districts and large-scale retail stores, and far from the highway interchanges. To identify the area-specific variables influencing the occurrence of housing abandonment, [PERSON] et al. [27] selected 424 dongs in Seoul as the target area and added the variables related to redevelopment or reconstruction, in addition to those related to the decline of the region.