# RECORD bbc85c0376ef4c6974813a189124a40708684478 # TITLE: PRICE CHANGES OF REPEAT-SALES HOUSES IN KAOHSIUNG CITY: ANALYSES BASED ON HIERARCHICAL LINEAR GROWTH MODELS # YEAR: 2023.0 VENUE: International Journal of Strategic Property Management DOI: 10.3846/ijspm.2023.19935 # AUTHORS: Chun-Chang Lee; Yu-Chen Wang; Chih-Min Liang; Zheng Yu # PAGES: 14 CANDIDATE TABLE PAGES (1-based): [9, 11] # ABSTRACT: This study adopts the hierarchical linear growth modeling approach to analyze the differences in the changes of repeat-sales house prices in Kaohsiung City from 2012 to 2020. The Level 1 time-varying factors include house age and the time of repeat-sales; the Level 2 factors include house attributes such as house area, house type, and house location. Based on the results of the null model, the estimated variance is 0.42816, with a 1% level of significance. This shows that significant differences exist in the mean repeat-sales prices between houses. The interclass correlation coefficient is 91.65%, showing that the interclass variation and intraclass variation of the mean repeat-sales prices are 91.65% and 8.35%, respectively. The estimation results of the non-randomly varying slope model indicate that the sales time and sales time squared significantly affect repeat-sales prices. The annual growth rate and quadratic growth of sales prices do not differ by house type (luxury condominiums and apartment buildings) but are affected by house area and house location. The effect of house age on repeat-sales prices is moderated by house area, house type, and house location. ===== PAGE 1 (score 14, numeric-paren 1, table-words 2, var-words 9) ===== Copyright © 2023 The Author(s). Published by Vilnius Gediminas Technical University This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unre- stricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Introduction On August 1, 2012, Taiwan began to implement a real estate actual price registration scheme. Before this, the previous sales prices of a new or pre-owned house had remained unavailable to housebuyers. However, the actual price registration scheme is unable to present the repeat- sales prices of the same house at different points in time. Therefore, the actual price registration scheme does not reveal whether changes in the price of a single house over time are in line with market conditions. The repeat-sales model was first proposed by Bailey et al. (1963) and was later reinterpreted and applied by Case and Shiller (1987). This model centers on analyzing the selling price of a single house at different points in time; it is generally used to formulate a real estate prop- erty price index. The interference of external factors can be reduced by observing the same property at different pe- riods, assuming that the structural, material, and external quality of the property remains unchanged. By combin- ing the repeat-sales approach with weighted indices and the hedonic price model, Shiller (1991) examined house International Journal of Strategic Property Management ISSN: 1648-715X / eISSN: 1648-9179 2023 Volume 27 Issue 5: 290–303 https://doi.org/10.3846/ijspm.2023.19935 *Corresponding author. E-mail: lcc@mail.nptu.edu.tw PRICE CHANGES OF REPEAT-SALES HOUSES IN KAOHSIUNG CITY: ANALYSES BASED ON HIERARCHICAL LINEAR GROWTH MODELS Chun-Chang LEE1,*, Yu-Chen WANG1, Chih-Min LIANG2, Zheng YU3 1 Department of Real Estate Management, National Pingtung University, Pingtung City, Taiwan 2 Department of Public Finance and Tax Administration, National Taipei University of Business, Taipei City, Taiwan 3 Department of Land Economics, National Chengchi University, Taipei City, Taiwan Received 18 January 2023; accepted 7 September 2023 Abstract. This study adopts the hierarchical linear growth modeling approach to analyze the differences in the changes of repeat-sales house prices in Kaohsiung City from 2012 to 2020. The Level 1 time-varying factors include house age and the time of repeat-sales; the Level 2 factors include house attributes such as house area, house type, and house location. Based on the results of the null model, the estimated variance is 0.42816, with a 1% level of significance. This shows that significant differences exist in the mean repeat-sales prices between houses. The interclass correlation coefficient is 91.65%, showing that the interclass variation and intraclass variation of the mean repeat-sales prices are 91.65% and 8.35%, respec- tively. The estimation results of the non-randomly varying slope model indicate that the sales time and sales time squared significantly affect repeat-sales prices. The annual growth rate and quadratic growth of sales prices do not differ by house type (luxury condominiums and apartment buildings) but are affected by house area and house location. The effect of house age on repeat-sales prices is moderated by house area, house type, and house location. Keywords: hierarchical linear growth modeling, repeat-sales, house prices, house area, house type, house location. price indices in Atlanta, Chicago, Dallas, and San Francis- co from 1970 to 1986. Clapp and Giaccotto (1998) wrote that the repeat-sales model increases the precision validity of the standard error in an estimator indicator. Recently, Beltrán et al. (2019) adopted the repeat-sales model to an- alyze the effects of flooding in England on property prices. The results show that property prices in completely inun- dated areas fell by 21%, although this reduction was only significant within five years. On the other hand, the effects of flooding on lower-priced houses lasted for 6 to 7 years. Ryu and Song (2020) applied the repeat-sales model to exploring the price of office spaces in Seoul. According to their results, the price of office spaces per 3.3 m2 per year has risen continuously by 12% from 2000 to 2019. However, many studies have analyzed the factors af- fecting house prices using the hedonic price model (Ros- en, 1974; Nelson & Schumaker, 2001; Umanailo et  al., 2019). Hox (1995) uniquely pointed out that estimating different levels of characteristic variables at the same in- dividual level will lead to fallacies in statistical inference. Giuliano et al. (2010) suggest that hierarchical linear mod- eling (HLM) can control the variation in research data ===== PAGE 9 (score 40, numeric-paren 2, table-words 16, var-words 3) ===== 298 C.-C. Lee et al. Price changes of repeat-sales houses in Kaohsiung city: analyses based on hierarchical... transferred house area among the 3,167 pieces of data is 125.079 m2 (SD = 60.879 m2); houses located in the sub- urbs accounted for 8.6% (273 pieces) of the sample, while houses located in the CBD accounted for 91.4% (2,894 pieces) of the sample; condominiums, luxury condomini- ums, and apartment buildings accounted for 20.1% (637 pieces), 10.3% (325 pieces), and 69.6% (2,205), respectively. In the same data period, there were 136,913 pieces of single sales data, and the mean house area was 134.48 m2 while the mean house age was 19.95 years. In terms of house type, condominiums, luxury condominiums, and apartment buildings accounted for 19.3%, 9.1%, and 71.6%, respectively. In terms of location, houses in the suburbs accounted for 9.1% while houses in the CBD ac- counted for 90.9%. The house attribute statistics did not vary greatly between the two samples. 4. Empirical results and analysis 4.1. Null model A null model was developed for this study to check for sig- nificant differences between the mean sales price of each house, as well as to examine the extent to which the vari- ation in house prices is caused by variation between the houses. The estimation results obtained through HLM6.08 software are presented in Table 4. As shown in Table 4, the estimated coefficient of the grand mean of the first sales price of each house (b00) is 6.132 and attains a 1% level of significance. In terms of random effects, the variance in Level 2 derived from the restricted maximum likelihood approach is 0.428, with a chi-square value of 80,509; it attains a 1% level of sig- nificance. This suggests that the mean house prices differ significantly. To understand whether the empirical results can be estimated through the HLGM approach, we first computed the intraclass correlation coefficient (ICC). The ICC was determined to be 0.91648, indicating that the in- terclass variance and intraclass variance of the repeat-sales prices account for 91.65% and 8.35% of the total variance respectively. In other words, the variance between the sales prices of a single house at different sales times ac- counts for 8.35% of the total variance. Therefore, it is suit- able to use the HLGM approach for subsequent analysis. 4.2. Non-randomly varying slope model The empirical results of the non-randomly varying slope model are presented in Table 5. In terms of fixed effects, the estimated coefficient of the grand mean of the first sales price of each house (b00) is 6.0497, attaining a 1% level of significance. The estimated coefficient of house area (b01) is 0.0088, attaining a 1% level of significance, which suggests that every 1-m2 increase in house area in- creases the sales price by 0.88% (converted using (eb –1) hereafter). The estimated coefficients of the two house types (b02 and b03) are 0.2395 and 0.4180, respectively, and both attain a 1% level of significance. This suggests that luxury condominiums and apartment buildings are 27.06% and 51.89% more expensive, respectively, than condominiums. The estimated coefficient of house loca- tion is 0.5478, attaining a 1% level of significance. This shows that houses in the CBD are 72.94% more expensive than those in the suburbs. Arribas et al. (2016) have dem- onstrated that, regardless of the regression model used for estimation, house attributes significantly affect sales prices. Therefore, the results of our study align with those of Arribas et al. (2016). Thhe estimated coefficient of the time of repeat-sales (b10) is 0.0382, attaining a 1% level of significance. This shows that the price of a house has grown annually by 3.89% from 2012 onwards. The estimated coefficient of the time of repeat-sales squared (b20) is –0.0035, attaining a 5% level of significance. This suggests that the curve of the quadratic growth of house prices in Kaoshiung City opens downward and that the growth rate of house prices gradually falls over time. In other words, an increase in the repeat-sales time increases the sales price of a house, and the margin diminishes with the sales time. In terms of moderating effects, the estimated interaction coef- ficient between house area and the time of repeat-sales (b11) is –0.0005 and attains a 5% level of significance. The interaction coefficient between house area and the time of repeat-sales squared (b21) is 0.0001, attaining a 1% level of significance. These findings indicate that an increase in house area reduces the growth rate of sales prices and that the quadratic growth gradually reduces over time. The estimated interaction coefficients between the two house types (Type1 and Type2) and the time of repeat-sales (b12 Table 4. Analysis results of the null model Fixed effects Coefficient Standard error t-ratio p-value Grand mean of the first sales price of each house b00 6.1317 0.0118 516.458 0.001*** Random effects Variance Degree of freedom Chi-square p-value Level 2 t00 Interclass variance 0.4282 3,166 80,509.915 0.001*** Level 1 s2 Intraclass variance 0.0394 Deviance 7,354.474 Number of estimated parameters 2 Note: *** denotes p < 0.01. Standard errors are presented as robust standard errors. ===== PAGE 10 (score 19, numeric-paren 0, table-words 6, var-words 6) ===== International Journal of Strategic Property Management, 2023, 27(5): 290–303 299 and b13) are 0.0049 and 0.0381, respectively, and do not attain a level of significance; the estimated interaction co- efficients between the two house types and the time of repeat-sales squared (b22 and b23) are 0.0002 and –0.0025, respectively, and also do not attain a level of significance. These findings indicate that the growth rate and quadratic growth (changes in the growth rate over time) of house prices are not moderated by house type. In other words, the annual growth in house prices do not differ by house types. The estimated interaction coefficient between house location and the time of repeat-sales (b14) is –0.1335, at- taining a 1% level of significance; the interaction coef- ficient between house area and the time of repeat-sales squared (b24) is 0.0182, attaining a 5% level of signifi- cance. These findings indicate that the growth rate and quadratic growth (changes in the growth rate over time) of house prices are moderated by house location. Houses in the CBD have a lower growth rate than those in the suburbs. Melser (2017) has demonstrated that houses in suburbs have a higher price appreciation than houses in the city center. Locational differences will diminish the differences in the growth rates of house prices over time. The estimated coefficient of house age (b30) is –0.0211 and attains a 1% level of significance; the estimated coeffi- cient of house age squared (b40) is 0.0005 and attains a 1% level of significance. This shows that an increase in house age reduces the sales price, and that the decrease becomes more gradual with decreasing house age. Soltani et  al. (2021) show that house age has the most substantial effect on sales prices, compared to other house attributes. Shi- mizu et al. (2010) concur that sales prices change over time and that such changes also vary continuously over time. Lyndsey et al. (2020) report that an increase in house age has diminishing effects on the sales prices of older houses and those suitable for redevelopment. In terms of moder- ating effects, the estimated interaction coefficient between house area and house age (b31) is 0.0001, attaining a 1% level of significance; the interaction coefficient between house area and house age squared (b41) is 0.000002, at- taining a 10% level of significance. These findings indicate that an increase in house area and house age will reduce the decrease in sales prices, and that the depreciation in sales prices accelerates with increasing house age. The es- timated interaction coefficients between Type1 houses and house age (b32) and house age squared (b42) are 0.0342 and –0.0008, attain levels of significance of 10% and 5%, respectively. This suggests that, compared to condomini- ums, the decrease in the prices of luxury condominiums is smaller when the house age is higher, while the rate of depreciation falls with an increasing house age. The esti- mated interaction coefficients between Type2 houses and house age (b33) and house age squared (b43) are 0.0278 and –0.0012, attaining levels of significance of 5% and 1%, respectively. This suggests that, compared to condomini- ums, the decrease in the prices of apartment buildings is smaller when the house age is higher, while the rate of depreciation falls with increasing house age. The estimated interaction coefficient between house location and house age (b34) is 0.0279 and attains a 1% level of significance; the interaction coefficient between house location and house age squared (b44) is –0.0008 and attains a 1% level of significance. These findings indicate that, compared to houses in suburbs, an increase in house age will reduce the decrease in the prices of houses in the CBD, while the de- preciation diminishes with increasing house age. Xu et al. (2018) have found that the added value of older houses in Beijing between 2005 and 2012 stems from the land itself rather than buildings on the land, while the price growth rate and quadratic growth are affected by house location. Liou et al. (2016) report that, between 2004 and 2012, the annual quadratic growth of house prices in Taipei City was faster than that of houses in New Taipei City. These findings demonstrate that the quadratic growth of house prices is affected by house location. In terms of random effects, p0i is a Level 2 variable used to interpret p0i based on the three Level 2 charac- teristics (i.e., house area, house type, and house location). r0i is the error term with an estimated variance (t00) of 0.0727 that has a significance of 1%. Therefore, p0i remains random even after controlling for the effects of the three Level 2 variables on house prices. In other words, other house attribute variables affect house prices. We apply the HLGM approach to analyze repeat-sales data. Our empirical results suggest that the annual growth rate and quadratic growth of sales prices do not differ by house type. The effects of house age and the time of re- peat-sales on sales prices are affected by house location and house area. Thus, the annual growth rate and qua- dratic growth of repeat-sales prices are affected by house location and house area. Controlling for the effects of the Level 2 variables (house area, house type, and house loca- tion) and a Level 1 variable (house age) on sales prices will reduce the random component of the initial price (p0i). Lastly, given that area is a continuous variable and its moderating effects cannot be plotted easily, and house type (Type1, Type2) did not significantly influence the re- lationship between the time variables and house price, we did not plot the effects of these variables. We only plotted the effects of house location on sales time and price; house type and location affected the relationship between house age and price (see Figures 3 to 5). Figure 3. The moderating effects of house location on the relationship between house price and sales time ===== PAGE 11 (score 43, numeric-paren 22, table-words 5, var-words 1) ===== 300 C.-C. Lee et al. Price changes of repeat-sales houses in Kaohsiung city: analyses based on hierarchical... Figure 4. The moderating effects of house type on the relationship between house price and age Figure 5. The confounding effects of house location on the relationship between house price and age Table 5. Analysis results of the non-randomly varying slope model Fixed effects Coefficient Standard error t-ratio p-value Grand mean of the first sales price of each house b00 6.0497 0.0186 325.730 0.001*** Area b01 Type1 b02 Type2 b03 Location b04 0.0088 0.2395 0.4180 0.5478 0.0003 0.0907 0.0698 0.0571 31.099 2.641 5.987 9.591 0.001*** 0.009*** 0.001*** 0.001*** Time – T b10 Area b11 Type1 b12 Type2 b13 Location b14 0.0382 –0.0005 0.0049 0.0381 –0.1335 0.0090 0.0002 0.0336 0.0282 0.0436 4.260 –2.222 0.146 1.350 –3.060 0.001*** 0.026** 0.884 0.177 0.003*** (Time – T)2 b20 Area b21 Type1 b22 Type2 b23 Location b24 –0.0035 0.0001 0.0020 –0.0025 0.0182 0.0014 0.00004 0.0050 0.0042 0.0072 –2.542 3.358 0.411 –0.578 2.499 0.011** 0.001*** 0.681 0.563 0.013** Age b30 Area b31 Type1 b32 Type2 b33 Location b34 –0.0211 0.0001 0.0342 0.0278 0.0279 0.0030 0.00003 0.0179 0.0113 0.0052 –7.090 3.271 1.910 2.459 5.286 0.001*** 0.001*** 0.056* 0.014** 0.001*** Age2 b40 Area b41 Type1 b42 Type2 b43 Location b44 0.0005 0.000002 –0.0008 –0.0012 –0.0008 0.00007 0.000001 0.0003 0.0002 0.0001 6.925 1.858 –2.450 –5.912 –5.247 0.001*** 0.063* 0.015** 0.001*** 0.001*** Variance Degree of freedom Chi-square p-value Level 2 t00 Interclass variance 0.0727 3,162 17,543.4250 0.001*** Level 1 s2 Intraclass variance 0.0369 Deviance 2,305.7188 Number of estimated parameters 2 Note: *** denotes p < 0.01; ** denotes p < 0.05; * denotes p < 0.1. Standard errors are presented as robust standard errors. ===== PAGE 12 (score 15, numeric-paren 0, table-words 3, var-words 7) ===== International Journal of Strategic Property Management, 2023, 27(5): 290–303 301 Conclusions and recommendations This study focuses on changes in the repeat-sales prices of houses over time in Kaohsiung City. The empirical re- sults suggest that the HLGM approach is a feasible means of exploring house price changes. Notwithstanding the wide availability of other options, examining changes in the sales prices of houses over time through ANOVA can only reveal relative changes in the sales prices between houses; it is unable to directly estimate changes in the sales prices of houses. Moreover, ANOVA does not account for measurement errors–nor does it include variables at the aggregate level (Level 2) for estimation (Lee et al., 2013). Arribas et al. (2016) demonstrate that the variance of each coefficient in HLGM is always smaller than those in OLS. This is because the lower estimation efficiency of OLS will result in a higher variance than that from HLGM. Fur- thermore, HLGM can also calculate the interclass vari- ance, as well as the ratio of the intraclass variance to the total variance (i.e., the ICC). OLS, on the other hand, can only derive the variance between the horizontal intraclass residuals. Not only is HLGM able to estimate changes in the growth curve of each housing transaction at different points in time, it can also examine the differences between individual-level data, which facilitates investigations into how house attributes affect changes in sales prices (Hsieh, 2015). After analyzing the advantages and drawbacks of each approach, showing that the HLGM approach is the appropriate method to examinine repeated observations in housing transactions over time. It can analyze the curves of the growth rate and quadratic growth of sales prices while elucidating how house attributes affect changes in the growth rate and quadratic growth of sales prices. According to the empirical results of the null model, the interclass error attained significance, suggesting that major differences exist in the mean house prices in this study, with an ICC of 91.65%. This means that the dif- ferences in housing prices caused by different house at- tributes accounted for 91.65% of the variance in the re- peat-sales data. The differences in housing prices of the same house caused by different sales periods accounted for 8.38% of the variance. This result cannot be obtained through a single-level repeat-sales model. The non-ran- domly varying slope model results indicate that the annual growth rate and quadratic growth of sales prices failed to attain significance in terms of the interaction coefficient between sales time and house type. This suggests that the effects of sales time on sales prices do not differ by house type. House area and house location moderate the effects of sales time on sales prices (i.e., both variables affect the growth rate and quadratic growth). The interaction coef- ficients between house area, house type, and house loca- tion are all significant, which implies that all three vari- ables moderate the effects of house age on sales prices. This finding shows that in repeat-sales data, the growth rate and the changes in the growth rate of the price of the same house are influenced by house area and house loca- tion. This result cannot be obtained through a single-level repeat-sales model. The empirical evidence demonstrates that house attributes are an important factor and modera- tor of the dynamic changes in repeat-sale house prices. The current repeat-sales approach suffers from con- ventional drawbacks, such as small sample sizes and sam- ple selection bias (Guo et al., 2014). We recommend that future studies perform HLGM analyses using panel data- based analytical methods. From July 1, 2021, onwards, house numbers must be disclosed on the actual price registration system. This measure would assist future re- searchers in performing accurate validations and would reduce the need to compare and analyze repeat-sales data. Additionally, house price indices can be developed using the HLGM approach. References Aiken, L. S., & West, S. G. (1991). Multiple regression: testing and interpreting interactions. Sage Publications Ltd. Anthony, O. A. (2018). Construction and application of property price indices. Routledge. Arribas, I., García, F., Guijarro, F., Oliver, J., & Tamošiūnienė, R. (2016). Mass appraisal of residential real estate using mul- tilevel modelling. International Journal of Strategic Property Management, 20(1), 77–87. https://doi.org/10.3846/1648715X.2015.1134702 Bailey, M. J., Muth, R. F., & Nourse, H. O. (1963). 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