# RECORD 7f206890031d1d54ba82515e526e51ef8c34c412 # TITLE: A Parsimonious Hedonic Distributional Regression Model for Large Data with Heterogeneous Covariate Effects # YEAR: 2025.0 VENUE: Austrian Journal of Statistics DOI: 10.17713/ajs.v54i2.1904 # AUTHORS: Julian Granna; Wolfgang A. Brunauer; Stefan Lang; Nikolaus Umlauf # PAGES: 25 CANDIDATE TABLE PAGES (1-based): [22] # ABSTRACT: Modeling real estate prices in the context of hedonic models often involves fitting a Generalized Additive Model, where only the mean of a (lognormal) distribution is regressed on a set of variables without taking other parameters of the distribution into account. Thus far, the application of regression models that model the full conditional distribution of the prices, has been infeasible for large data sets, even on powerful machines. Moreover, accounting for heterogeneity of effects regarding time and locale, is often achieved by naive stratification of the data rather than on a model basis. A novel batchwise backfitting algorithm is applied in the context of a structured additive distributional regression model, which enables us to efficiently model all distributional parameters of the price distribution. Using a large German dataset of apartment asking prices with over one million observations, we employ a model-based clustering algorithm to capture the heterogeneity of covariate effects on the parameters with respect to dwelling locale. We thus identify clusters that are homogeneous with respect to the influence of dwelling locale on price. A boosting type algorithm of the batchwise backfitting algorithm is then used to automatically determine the variables relevant for modelling the location and scale parameters in each regional cluster. This allows for a different influence of variables on the distribution of prices depending on the locale and price segment of the dwelling. ===== PAGE 1 (score 5, numeric-paren 0, table-words 1, var-words 3) ===== AJS Austrian Journal of Statistics 2025, Volume 54, 44–68. http://www.ajs.or.at/ doi:10.17713/ajs.v54i2.1904 A Parsimonious Hedonic Distributional Regression Model for Large Data with Heterogeneous Covariate Effects Julian Granna University of Innsbruck Innsbruck, Austria Wolfgang Brunauer DataScience Service GmbH Vienna, Austria Stefan Lang University of Innsbruck Innsbruck, Austria Nikolaus Umlauf University of Innsbruck Innsbruck, Austria Abstract Modeling real estate prices in the context of hedonic models often involves fitting a Generalized Additive Model, where only the mean of a (lognormal) distribution is re- gressed on a set of variables without taking other parameters of the distribution into account. Thus far, the application of regression models that model the full conditional distribution of the prices, has been infeasible for large data sets, even on powerful ma- chines. Moreover, accounting for heterogeneity of effects regarding time and locale, is often achieved by naive stratification of the data rather than on a model basis. A novel batchwise backfitting algorithm is applied in the context of a structured addi- tive distributional regression model, which enables us to efficiently model all distributional parameters of the price distribution. Using a large German dataset of apartment asking prices with over one million observations, we employ a model-based clustering algorithm to capture the heterogeneity of covariate effects on the parameters with respect to dwelling locale. We thus identify clusters that are homogeneous with respect to the influence of dwelling locale on price. A boosting type algorithm of the batchwise backfitting algorithm is then used to automatically determine the variables relevant for modelling the location and scale parameters in each regional cluster. This allows for a different influence of variables on the distribution of prices depending on the locale and price segment of the dwelling. Keywords: generalized additive models for location scale and shape, hedonic regression, re- gional cluster, real estate prices. 1. Introduction Rosen (1974) interprets hedonic prices as the sum of implicit prices of attributes of a good. These directly unobservable prices, hence often referred to as "shadow prices", are estimated ===== PAGE 22 (score 24, numeric-paren 0, table-words 2, var-words 15) ===== Austrian Journal of Statistics 65 A. Descriptive tables Table 2: Summary statistics of variables considered for modeling. Arithmetic mean is pro- vided for metric covariates, relative frequency for discrete variables (Part 1). variable description mean / rel. frequency std. deviation min max ppqm Price per square meter 2.070 0.080 1.360 2.420 log.ppqm log(Price per square meter) 7.930 0.600 3.910 11.260 age Age of flat in years 37.680 30.230 -4.000 119.000 area Area of flat in square meters 80.080 32.380 21.000 240.000 quarter Quarter of last offer 2019.200 2.010 2016.000 2022.500 KGS county ID balcony Whether object has balcony 0 = no 0.435 1 = yes 0.565 built.in.kitchen Whether object has built-in kitchen 0 = no 0.993 1 = yes 0.007 cellar Whether object has a cellar 0 = no 0.461 1 = yes 0.539 condition condition of object 1 = other 0.634 2 = first-time occupancy 0.161 3 = renovated 0.173 4 = in need of renovation 0.031 cul.de.sac Whether object is located in cul de sac 0 = no 0.998 1 = yes 0.002 district.heating Whether object features district heating 0 = no 0.946 1 = yes 0.054 electric.heating Whether object has electric heating 0 = no 0.997 1 = yes 0.003 elevated.ground.floor Whether object is on elevated ground floor 0 = no 0.994 1 = yes 0.006 floor.boards Whether object has floorboards 0 = no 0.995 1 = yes 0.005 floor.heating Whether object has floor heating 0 = no 0.909 1 = yes 0.091 furnished Whether object is furnished 0 = no 0.967 1 = yes 0.033 garage Whether object has a garage 0 = no 0.882 1 = yes 0.118 garden Whether object features a garden 0 = no 0.924 1 = yes 0.076 garden.share Whether object inlcudes share of a garden 0 = no 0.990 1 = yes 0.010 garden.use Whether object inlcudes a shared garden 0 = no 0.997 1 = yes 0.003 geothermal.heating Whether object features geothermal heating 0 = no 0.998 1 = yes 0.002 ===== PAGE 23 (score 21, numeric-paren 0, table-words 1, var-words 15) ===== 66 Hedonic Distributional Regression for Large Data with Heterogeneous Effects Table 3: Summary statistics of variables considered for modeling. Arithmetic mean is pro- vided for metric covariates, relative frequency for discrete variables (Part 2). variable description mean / rel. frequency std. deviation min max heating.type Type of heating in dwelling 1 = other 0.079 2 = unknown 0.661 3 = district_heating 0.052 4 = gas 0.189 5 = oil 0.019 hereditary.lease Whether dwelling is hereditary lease type 0 = no 0.984 1 = yes 0.016 historic.preservation Whether dwelling is historically preserved 0 = no 0.978 1 = yes 0.022 laminated.flooring Whether object features laminated flooring 0 = no 0.954 1 = yes 0.046 lift Whether object features a lift 0 = no 0.710 1 = yes 0.290 maisonette Whether object has multiple floors 0 = no 0.944 1 = yes 0.056 no..of.rooms Number of rooms in the flat 1 0.092 2 0.310 3 0.389 4 0.160 > 5 0.049 north.facing Whether object is facing north 0 = no 0.999 1 = yes 0.001 refurbished.flat Whether object is refurbished 0 = no 0.809 1 = yes 0.191 rented Whether object is rented 0 = no 0.719 1 = yes 0.281 skyscraper Whether object is located in skyscraper 0 = no 0.999 1 = yes 0.001 solar.power Whether object features solar power 0 = no 0.997 1 = yes 0.003 south.facing Whether object is facing south 0 = no 0.997 1 = yes 0.003 storage.room Whether object has a storage room 0 = no 0.993 1 = yes 0.007 underground.parking Whether object has underground parking 0 = no 0.871 1 = yes 0.129 wellness Whether object has a wellness area 0 = no 0.996 1 = yes 0.004 winter.garden Whether object has a winter garden 0 = no 0.994 1 = yes 0.006