# RECORD 75ba68147bf6e34f9b631b70a8cea636eda11e65 # TITLE: Use of Geographically Weighted Regression (GWR) Method to Estimate the Effects of Location Attributes on the Residential Property Values # YEAR: 2017.0 VENUE: nan DOI: 10.22146/ijg.27036 # AUTHORS: M. Dziauddin; Z. Idris # PAGES: 14 CANDIDATE TABLE PAGES (1-based): [6, 7] # ABSTRACT: This study estimates the effect of locational attributes on residential property values in Kuala Lumpur, Malaysia. Geographically weighted regression (GWR) enables the use of the local parameter rather than the global parameter to be estimated, with the results presented in map form. The results of this study reveal that residential property values are mainly determined by the property’s physical (structural) attributes, but proximity to locational attributes also contributes marginally. The use of GWR in this study is considered a better approach than other methods to examine the effect of locational attributes on residential property values. GWR has the capability to produce meaningful results in which different locational attributes have differential spatial effects across a geographical area on residential property values. This method has the ability to determine the factors on which premiums depend, and in turn it can assist the government in taxation matters. ===== PAGE 1 (score 13, numeric-paren 0, table-words 0, var-words 13) ===== Use of Geographically Weighted Regression (GWR) Method to Estimate the Effects of Location Attributes on the Residential Property Values Mohd Faris Dziauddin and Zulkefli Idris Received: 08 04 2016 / Accepted: 24 08 2016 / Published online: 30 06 2017 © 2017 Faculty of Geography UGM and The Indonesian Geographers Association Abstract This study estimates the effect of locational attributes on residential property values in Kuala Lumpur, Malay­ sia. Geographically weighted regression (GWR) enables the use of the local parameter rather than the global parameter to be estimated, with the results presented in map form. The results of this study reveal that residential property values are mainly determined by the property’s physical (structural) attributes, but proximity to locational attributes also con­ tributes marginally. The use of GWR in this study is considered a better approach than other methods to examine the effect of locational attributes on residential property values. GWR has the capability to produce meaningful results in which different locational attributes have differential spatial effects across a geographical area on residential property values. This method has the ability to determine the factors on which premiums depend, and in turn it can assist the government in taxation matters. Abstrak Studi ini memperkirakan pengaruh atribut lokasi terhadap nilai properti residensial di Kuala Lumpur, Malaysia. Regresi berbobot secara geografis (GWR) diperkirakan memungkinkan penggunaan parameter lokal daripada parameter global , dengan hasil disajikan dalam bentuk peta. Hasil penelitian ini mengungkapkan bahwa nilai properti residensial terutama ditentukan oleh atribut fisik (struktural) properti, namun kedekatan dengan atribut lokasional juga berkontribusi sedikit. Penggunaan GWR dalam penelitian ini dianggap sebagai pendekatan yang lebih baik daripada metode lain untuk menguji pengaruh atribut lokasi terhadap nilai properti residensial. GWR memiliki kemampuan untuk menghasilkan hasil yang berarti dimana atribut lokasi yang berbeda memiliki efek spasial yang berbeda di wilayah geografis mengenai nilai properti residensial. Metode ini memiliki kemampuan untuk menentukan faktor-faktor dimana premi bergantung, dan pada gilirannya dapat membantu pemerintah dalam hal perpajakan. Keywords: Geographically weighted regression; Kuala Lumpur ; Location attributes; Residential property values Kata kunci: Atribut lokasi; Kuala Lumpur ; Nilai properti perumahan; Regresi tertimbang secara geografis. 1.Introduction Location is acknowledged as an important attribute of immovable objects such as land and improvements to land. In the last five decades or so, many studies have been conducted to investigate the effect of location on land values and subsequently residential property values. In the standard practice of property valuation, property location is considered the most important factor in determining property value because the physical structure of the property depreciates over time. The land underneath the physical structure is what increases in value, and this is why the most common mantra we usually hear from real estate practitioners is ‘location, location and location’. The theory of property value formation examines location as a composite effect of a set of locational Mohd Faris Dziauddin Department of Geography & Environment Faculty of Human Sciences, Sultan Idris Education University, 35900 Tanjong Malim, Perak, Malaysia. Zulkefli Idris UMW Technology Sdn. Bhd.16-1, Level 16, Menara Prestige No 1, Jalan Pinang, 50450 Kuala Lumpur. Malaysia. Correspondent E-mail: faris@fsk.upsi.edu.my attributes [Kauko, 2003]. In other words, attributes such as the central business district (CBD), parks, shopping malls, schools, rail transit systems, highway, etc. may contribute positively towards the formation of a residential property value, particularly in urban areas. It has to be noted that, the benefits of locational attributes are realised mainly in the form of externalities, hence they are collectively shared by a large number of people and houses [Kauko, 2003; Orford, 1999]. Externalities can be positive (beneficial) and negative (harmful). For example, rail transit systems can generate both positive (improve accessibility) and negative externality (traffic congestion and noise pollution) effects. Since an assessment of the relationship between residential property values and a locational externality effect will benefits the government, housing developers and home buyers, it is important to evaluate their relationship in monetary terms. The most commonly used method to estimate the value formation of a residential property in monetary terms is hedonic pricing model (HPM). HPM is a well- established technique used for analysing a market for a single commodity with many attributes, in particular ISSN 2354-9114 (online), ISSN 0024-9521 (print) Indonesian Journal of Geography Vol. 49, No.1, June 2017 (97 - 110) DOI: http://dx.doi.org/10.22146/ijg.2323, website: https://jurnal.ugm.ac.id/ijg © 2017 Faculty of Geography UGM and The Indonesian Geographers Association ===== PAGE 6 (score 40, numeric-paren 0, table-words 7, var-words 17) ===== USE OF GEOGRAPHICALLY WEIGHTED REGRESSION Mohd Faris Dziauddin, et all 102 from the Environmental Systems Research Institute support centre. The network–distance measurement using this programme requires three layers of spatial data: points of origin (observations), points of destinations (locational attributes) and road network data. This measurement allows the shortest route from each observation to the locational attributes to be calculated. Moreover, the Multiple Origins to Multiple Destinations programme enables more than one destination to be selected at any one time. Thus, proximity to the locational attributes can be calculated simultaneously for each observation. Table 1 presents a list of explanatory variables considered for inclusion in the HPM together with their descriptive statistics. In all regression-based analysis, some explanatory variables are usually multicollinear. To handle this problem, the correlations among the explanatory variables used for the inclusion in the final models were detected by using Pearson’s correlation coefficient and variance inflation factors (VIFs). Following Orford [1999], a Pearson’s correlation coefficient above 0.8 and a VIF above 10 indicate harmful collinearity. This rule was applied in this study. 3. Results and Discussion The results of the HPM and GWR models are presented in two stages: the first part shows the results from the HPM and the second part shows the results from the GWR model. The HPM Estimation According to the seminal works in the area of hedonic pricing of Rosen [1974], Freeman [1979b], Halvorsen and Pollawski [1981] and Palmquist [1984], four common functional forms are used to measure the relationship between the dependent and the explanatory variables in HPM: linear, semi-log, double- log and Box-Cox transformations. Unfortunately, no studies have been conducted on how to choose a particular functional form in HPM except for the work of Cropper et al. [1988], which extensively reviewed the choice of functional form for HPM by previous researchers. This study concluded that linear, semi- log, double-log and Box-Cox linear perform best with quadratic forms, with the quadratic Box-Cox faring relatively poorly. After performing and comparing these functional forms for the data in this study, we found that the semi-log functional form performed the best, and thus we used it estimate the relationship being studied. The semi-log regression equation is regressed on a set of determinants as follows: lnPi = β0 + β1FREEHOLDi + β2FLOORSIZEi + β3LOTSIZEi + β4BEDROOMSi + β5TYPE TERRACEDi + β6TYPE_TOWNHOUSEi + β7TYPE_SEMIDETACHEDi + β8TYPE BUNGALOWi + β9PRIMARY_SCHOOLi + β10SECONDARY_SCHOOLi + β11SHOPMALLi + β12FORESTi + β13RAIL STATIONi + β14MALAYi + β15CHINESEi + εi.......(4) Table 1. A list of explanatory variables and descriptive statistics of the model’s variables Variable Hedonic price model (HPM) GWR model Coefficients (β) Standardised coefficients (β) t-ratio Lower quartile Median Upper quartile Intercept 11.647 0.159 183.944 11.080 11.985 12.328 FREEHOLD 0.294 0.542 18.733 0.084 0.155 0.232 FLOORSIZE 0.005 0.086 49.578 0.004 0.005 0.005 LOTSIZE 1.860E-4 0.108 9.593 4.800E-4 4.030E-4 0.001 BEDROOMS 0.190 -0.043 11.497 0.076 0.132 0.173 TYPE_TERRACED -0.084 -0.062 -2.841 0.038 0.290 0.391 TYPE_TOWNHOUSE -0.223 0.124 -5.645 -0.210 0.024 0.179 TYPE_SEMIDETACHED 0.357 0.096 10.454 0.338 0.571 0.635 TYPE_BUNGALOW 0.442 0.031 9.869 0.182 0.361 0.497 PRIMARY_SCHOOL 2.832E-5 0.070 2.783 2.700E-5 1.400E-5 8.500E-5 SECONDARY_SCHOOL 5.244E-5 -0.112 6.881 9.000E-6 3.900E-5 1.070E-4 SHOPMALL -8.112E-5 0.052 -11.385 -8.000E-5 -5.600E-5 -4.000E-6 FOREST -2.973E-5 -0.018 -5.934 -2.200E-5 -4.000E-6 8.000E-6 RAIL_STATION -0.036 0.117 -2.132 -0.073 -0.019 0.030 MALAY 0.041 0.067 12.629 0.006 0.033 0.070 CHINESE 0.025 7.416 -0.037 -0.002 0.025 Notes: Goodness of fit: Adjusted R2=0.73 (HPM); adjusted R2=0.85 (GWR). AICc=5663.63 (HPM); AICc=3185.55 (GWR) ===== PAGE 7 (score 43, numeric-paren 0, table-words 7, var-words 20) ===== Indonesian Journal of Geography, Vol. 49 No. 1, June2017: 97- 109 103 where i is the subscript denoting each property, Pi is the price of property i in Malaysian Ringgit (MYR), ln is the natural logarithm; FREEHOLD is the dummy variable that indicates the status of ownership of the property, FLOORSIZE is the floor area of the property measured in square metre, LOTSIZE is the lot size of the property measured in square metre, BEDROOMS is the dummy variable that indicates a property with four or more bedrooms, TYP xxx is the set of dummy variables that illustrates the type of house, and it is further described as follows: TYPE_TERRACED is 1 if the property is cluster, 0 otherwise; TYPE_TOWNHOUSE is 1 if the property is town house, 0 otherwise; TYPE_SEMIDETACHED is 1 if the property is semi- detached, 0 otherwise; TYPE_BUNGALOW is 1 if the property is bungalow, 0 otherwise. PRIMARY_SCHOOL, SECONDARY_SCHOOL, SHOPMALL and FOREST are the network–distance variables measured in metres from the property to primary schools, secondary schools, shopping malls and forests, respectively. RAIL_STATION is the dummy variable that indicates properties within a 2 km radius to the nearest station. The 2 km radius is chosen in accordance with the theory of the rail transit system– residential property value relationship. MALAY and CHINESE are the percentages of residents from the Malay and Chinese ethnic groups. β0,...,β15 denotes a set of parameters to be estimated on the explanatory variables (including the intercept term), and εi is the standard error of the estimation assumed to be independently and identically distributed. The parameter estimates for HPM together with the GWR model are shown in Table 2. In general, HPM explains approximately 73% of the variation in the dependent variable, consistent with other published empirical results. In the final model, all of the explanatory variables that influenced residential property values were significant at the 1% level. Note that explanatory variables were incorporated in the final model based on significant coefficient values, and they alleviated the potential issues of multicollinearity. As the model is a semi-log functional form, the interpretation of the parameter estimates relates to their proportional (or their percentage when multiplied by 100) effect on price. Among the structural attributes, property size, which is measured by floor size (FLOORSIZE), is the most significant contribution to the value formation of a residential property. Specifically, for every square metre increase in floor size, the expected selling price of a residential Table 2. Estimation results of the global (HPM) and local (GWR) models (n=4393) Variable Hedonic price model (HPM) GWR model Coefficients (β) Standardised coefficients (β) t-ratio Lower quartile Median Upper quartile Intercept 11.647 183.944 11.080 11.985 12.328 FREEHOLD 0.294 0.159 18.733 0.084 0.155 0.232 FLOORSIZE 0.005 0.542 49.578 0.004 0.005 0.005 LOTSIZE 1.860E-4 0.086 9.593 4.800E-4 4.030E-4 0.001 BEDROOMS 0.190 0.108 11.497 0.076 0.132 0.173 TYPE_TERRACED -0.084 -0.043 -2.841 0.038 0.290 0.391 TYPE_TOWNHOUSE -0.223 -0.062 -5.645 -0.210 0.024 0.179 TYPE_SEMIDETACHED 0.357 0.124 10.454 0.338 0.571 0.635 TYPE_BUNGALOW 0.442 0.096 9.869 0.182 0.361 0.497 PRIMARY_SCHOOL 2.832E-5 0.031 2.783 2.700E-5 1.400E-5 8.500E-5 SECONDARY_SCHOOL 5.244E-5 0.070 6.881 9.000E-6 3.900E-5 1.070E-4 SHOPMALL -8.112E-5 -0.112 -11.385 -8.000E-5 -5.600E-5 -4.000E-6 FOREST -2.973E-5 0.052 -5.934 -2.200E-5 -4.000E-6 8.000E-6 RAIL_STATION -0.036 -0.018 -2.132 -0.073 -0.019 0.030 MALAY 0.041 0.117 12.629 0.006 0.033 0.070 CHINESE 0.025 0.067 7.416 -0.037 -0.002 0.025 Notes: Goodness of fit: Adjusted R2=0.73 (HPM); adjusted R2=0.85 (GWR). AICc=5663.63 (HPM); AICc=3185.55 (GWR) ===== PAGE 8 (score 14, numeric-paren 0, table-words 4, var-words 6) ===== USE OF GEOGRAPHICALLY WEIGHTED REGRESSION Mohd Faris Dziauddin, et all 104 property increases by 0.5% (at the mean value, this equates to a premium of MYR 4331 or USD 1379, with the FOREX rate at MYR 3.14 or USD 1.00 in December 2010). Among the locational attributes, distance to a local shopping mall is the most statistically significant. The model suggests that for every metre away from a local shopping mall, residential property values are likely to decrease at approximately 0.008% (at the mean value, this equates to MYR 70 or USD 22), thus signifying a strong appreciation of house buyers for this locational attribute category. The distance to rail transit stations (RAIL_STATION) is the least statistically significant locational attribute, and it has a counter- intuitive sign. Residential properties are estimated to be sold at discounts of up to 3.6%, which is equal to MYR 31,181 (USD 9930) at the mean value, in a radius of 2 km to the nearest station. Among neighbourhood variables, the percentage of residents from the Malay ethnic group contributes most significantly to the value formation of a residential property. For every 1% increase in ethnic Malay (MALAY), residential property values are likely to increase by about 4.1 %, which is equal to MYR 35,512 (USD 11,309). In all regression-based analyses, the independent variables possess various units of measurements, and thus their relative importance to the dependent variable is difficult to assess. To help overcome this difficulty, the computer-intensive LMG method developed by Lindeman et al. [1980] can be used to decompose R2 [Grömping, 2006]. The LMG method can be written in the following form [Christensen, 1992]: where n(S) is the number of variables included in the set of regressors S. Therefore, LMG is defined as the average contributions in models of different sizes. The order of the regressors in any model is a permutation of available regressors x1, …, xp, which is denoted by the tuple of indices r. When the unit of measurement for independent variables is standardised, the relative importance of these variables on the dependent variable can be determined. The results from the LMG method indicate that structural variables are more influential than locational and neighbourhood variables in estimating residential property values. Specifically, the structural attributes Figure 2. Shares of relative importance (LMG) for residential property values, OLS-Model (Note: The R2 with significant variables is 73%)