1. Introduction
Walkable environments correlate with increased walking, biking, and physical activity [
1,
2,
3], a reduction in diseases, and an improvement in overall health [
4,
5,
6,
7]. Moreover, increasing evidence has suggested that a walkable environment can have an impact on environmental and social benefits. A walkable environment may improve air pollution through reduced use of vehicles [
8,
9,
10], increased safety through reduced crime rates [
11,
12,
13], and promote social cohesion through increased social interaction among residents [
14,
15]. Therefore, many professionals, including urban planners and designers, transportation engineers, environmental scientists, public health scientists, and even policy makers, endeavor to create walkable environmental conditions in urban contexts.
In 2016, the city of Seoul implemented a project called “Walkable City, Seoul” to improve Seoul’s pedestrian environment and its citizens’ quality of life. To launch this project, the city of Seoul suggested the slogan, “Good bye Car, Good day Seoul” and implemented four policy directions, including “Possible to walk”, “Easy to walk”, “Want to walk”, and “Walk together” [
16]. Before “Walkable City, Seoul” was launched, Seoul had made significant efforts to create a pedestrian-friendly environment, and perhaps as a result of that, the health behavior of Seoul citizens has increased over the past decade. According to the Community Health Survey, the rate of walking has increased from 57.3% (2008) to 61.5% (2017), while the rate of moderate to vigorous physical activity has also increased from 19.1% (2009) to 22.2% (2017) over the last decade [
17].
As mentioned above, a walkable environment has many health, environmental, and social benefits, so it may also be considered one of the most important factors in residents’ choice of housing, and it may even affect housing prices. Many empirical studies show that the level of walkability in a neighborhood has a positive correlation with property values [
18,
19,
20,
21,
22]. For example, Leinberger and Alfonzo found that the housing prices in walkable neighborhoods were higher than those in less walkable neighborhoods in Washington, D.C. [
18]. Some researchers have employed the walk score as an indicator of the walkability level and have used it to estimate the impact on real estate values. Cortright conducted a study in 15 metropolitan areas in the United States and found that when the walk score increased by an additional one point, housing prices would increase from US
$700 to
$3000 [
19]. Washington focused on 259 large cities with a population of over 100,000 in the United States and found that a one-point increase in the walk score would increase housing prices by about 0.5% [
20]. Pivo and Fisher found that a 10-point increase in the walk score value increased the property value by 1% to 9%, depending on the type of property in the United States [
21]. Rauterkus and Miller also found a significantly positive relationship between the walk score and land values in Jefferson County, Alabama [
22]. These studies were all carried out in the United States because walk score data by address are only available in the United States and Canada [
23].
This has led to many efforts to develop the walkability indicator adapted from the walk score methodology in Europe and Asia. Reyer et al. tried to develop the walk score and investigate its association with active transportation in Stuttgart, Germany [
24]. Zhang et al. also calculated the walkability level and defined its relationship with residential estate value in Futian District, China [
25]. In particular, Zhang and colleagues’ study found a negative association between walkability and housing prices in 2018. In Korea, efforts have been made to produce walkability data, and Kim et al. calculated the walkability score throughout all of Seoul. As in the case of Stuttgart and Futian, Seoul’s walkability score was basically adopted from the walk score methodology derived from the United States [
26].
How does the walkability score correlate with housing prices in Seoul? It may be negatively correlated, as was the case in Zhang and colleagues’ study, or positively correlated, as in other studies carried out in the United States. As shown in previous studies in the United States, the level of walkability is calculated based on the accessibility of the amenities local residents need to live their daily lives, which is typically reflected in the neighborhood’s housing prices [
18,
19,
20,
21,
22]. On the other hand, Zhang and colleagues’ study obtained a contrary result, because their study area (Futian District, China) was characterized by rapid urbanization and car-dependent urban form. Therefore, it can be inferred that housing prices in Futian District may have been more influenced by factors other than the walkability of the neighborhood. There has been little research on the relationship between walkability and housing prices using objectively measured variables in Seoul, Korea. The aim of this study is to examine the relationships between the level of environmental walkability and housing prices at the neighborhood level. The walkability score is identified as the key independent variable in this research. The following hypothesis will be tested:
H1. Areas with more walkable environments have a higher housing price than those with less walkable environments.
4. Discussion and Conclusions
It is often said that a walkable environment is one of the most important factors in selecting a residence. People want to walk and ride bikes in their neighborhoods. Some studies show that the level of walkability in neighborhoods is positively correlated with housing prices [
18,
19,
20,
21,
22]. The walk score is widely used as an indicator of the walkability level in a neighborhood [
82]. This study examined 5986 apartment complexes in Seoul, Korea, all of which had conducted transactions in 2017. Using both spatial regression models and the OLS regression model, we established and empirically analyzed our research hypothesis as follows: “Areas with more walkable environments have a higher housing price than those with less walkable environments”.
The overall findings of the study are summarized in the following points. First, the hypothesis of this study is half correct. There was no significant relationship between the walkability score and housing prices across all of Seoul, but different results were revealed when Seoul was divided into two subsamples: a significant correlation was revealed between the walkability score and housing prices in areas with high housing prices, whereas no statistical relationship existed between them in areas with low housing prices. When considering the level of walkability as a factor influencing housing prices, it is difficult to encapsulate the entire housing market in Seoul. Second, although the relationship was only statistically significant in areas with low housing prices, a positive correlation was observed between the walkability score and housing prices, as shown in previous studies in the United States [
19,
20,
21,
22]. In particular, results showed that a one-point increase in the walkability score would increase housing prices by about 0.2% in areas with low housing prices. Third, there was no significant correlation between the walkability score and housing prices in areas with high housing prices. Interestingly, the quality of high school, as measured by the SKY league admission rate, was a very important factor for housing prices in areas with high housing prices. In Seoul, schools of good quality are mostly located in areas with high housing prices [
47,
48], consequently, the result showed a strong, positive correlation with the quality of high school and housing prices in those areas. This is in line with the results of preceding studies, which showed that the quality of the high school in the Gangnam Area (commonly referenced as Gangnam-gu, Seocho-gu, and Songpa-gu) is a very important factor in the elevation of housing prices [
47,
48,
49]. In addition, this can be interpreted as representing the symbolic characteristics of the Gangnam Area in Seoul. The Gangnam Area transcends its function as simply a residential area, as the residents who live there also assume a socially superior status. That is, the level of walkability in the neighborhood may not be considered in the Gangnam Area and its neighboring districts as a factor in determining housing prices. Fourth, additional environmental variables were correlated with housing prices. The distance to the subway station had a significantly negative correlation with housing prices in areas with low housing prices, while no statistical relationship was found between them in areas with high housing prices. This result could be explained with the relatively high dependence on public transport in areas with low housing prices compared to that of areas with high housing prices. Housing prices were significantly associated with the mean slope (−) and the mean NDVI (+) of neighborhood environmental conditions in both subsample areas.
Although this study provides a greater understanding of the relationship between walkability and housing prices in Seoul, it has several limitations, which suggest directions for future studies. First, the walkability score needs to be revised and developed to better evaluate the level of walkability in a given neighborhood. Although the factor of park accessibility was already considered in the walkability score calculation, the mean NDVI showed a positive correlation with housing prices. This means that greenness can be an important factor that cannot be overemphasized in residential housing selection for urban dwellers. When developing the walkability index in further study, it is necessary to give greater consideration to the greenness factor. Second, it is required to divide Seoul into more disaggregated areas to examine the correlation between the level of walkability and housing prices. Based on the examination of the spatial patterns of the walkability score and the housing prices, this study divided Seoul into two groups (the top 30% of the housing prices vs. the bottom 70% of the housing prices). To produce more meaningful results, future research may allow further subdivision of groups (e.g., subdivisions by 25 municipalities). This can help to suggest practical implications for establishing housing and/or urban regeneration policies. Moreover, another limitation of this study is its cross-sectional design. It is necessary to examine the correlation between the walkability and housing prices in areas where housing prices have recently surged and/or markedly dropped. If we examine the correlation between these two factors before and after the housing price transition, this would give us a closer look at the importance of walkability level as a determinant of housing prices.
This study examined the correlation between the level of walkability and housing prices, which has been studied substantially in the United States and other countries. It is meaningful to analyze 5,986 apartment complexes throughout all of Seoul, not limited to some districts. Following our examination of the hypothesis regarding the correlation between walkability and housing prices, we also observed an additional interesting result: the correlation differed depending on a given area. This study is significant because it revealed a positive correlation between walkability and the housing prices in areas with low housing prices; meanwhile, no significant relationship was observed in areas with high housing prices. This suggests that policies tailored to regional characteristics need to be addressed. The results of this study can be used to suggest public policy proposals in urban planning, environmental design, and housing policies.