Changes in risk appreciation, and short memory of house buyers when the market is hot, a case study of Christchurch, New Zealand

Figures & data

Table 1. Input data for pre-lockdown period $\mathit{n}=1091$.

Variable	Data Type	Min	Max	Mean	Std. Dev.
Log Real Price	Floating point	4.719	7.588	5.298	0.337
Bedrooms	Integer	2	9	–	0.794
Bathooms	Integer	1	4	–	0.608
Toilets	Integer	1	4	–	0.773
Carparks	Integer	1	6	–	0.567
Floor Area	Floating Point	62.0${\mathrm{m}}^2$	498.0${\mathrm{m}}^2$	161.6${\mathrm{m}}^2$	64.031
Land Area	Floating Point	219.0${\mathrm{m}}^2$	2925.0${\mathrm{m}}^2$	690.8${\mathrm{m}}^2$	203.880
Position of Property	Categorical	–	–	–	–
Roof Condition	Categorical	–	–	–	–
View from Property	Categorical	–	–	–	–
Wall Condition	Categorical	–	–	–	–
Dist. CBD	Floating point	0.237$\mathrm{km}$	13.498$\mathrm{km}$	6.018$\mathrm{km}$	1.927
Dist. to Secondary	Floating point	0.101$\mathrm{km}$	8.841$\mathrm{km}$	1.760$\mathrm{km}$	1.213
Dist. to Secondary	Floating point	0.101$\mathrm{km}$	8.841$\mathrm{km}$	1.760$\mathrm{km}$	1.213
Technical Category	Categorical	–	–	–	–
Age Purchased	Integer	0	119	47.67	25.884
NZ Deprivation Score	Integer	846	1249	969.9	70.870
School Zone	Categorical	–	–	–	–
Ward	Categorical	–	–	–
(Age Purchased)^2	Integer	0	14161	2941.890	2722.924

Table 2. Hedonic regression estimates by time period.

Variable	2014–2016	2019–2020	2020–2021
	Coefficient (SE)	Coefficient (SE)	Coefficient (SE)
Intercept	6.008*** (2.161e–1)	5.572*** (9.888e–;2)	5.622*** (8.017e–2)
Bedrooms	2.618e– (2.950e–2)	−3.748e–4 (1.129e-2)	−4.603e–2*** (9.502e–3)
Bathrooms	−2.615e–2 (3.580e–2)	2.963e–3 (1.551e–2)	2.236e–2† (1.247e–2)
Toilets	4.900e–2 (3.261e–2)	1.782e–2 (1.331e–2)	2.808e–2 ** (1.033e–2)
Carparks	2.227e–2 (1.895e–2)	2.790e–3 (9.303e–3)	1.616e–3 (6.807e–3)
Floor Area	1.876e–3***(3.674e–4)	2.202e–3*** (1.564e–4)	2.349e–3*** (1.238e–4)
Land Area	1.068e–4† (6.470e–5)	2.110e–4***(2.568e–5)	2.488e–4*** (2.113e–5)
RoofCondition Fair	1.559e–2 (2.292e–1)	2.704e–2 (7.450e–2)	−4.566e–2 (6.329e–2)
RoofCondition Good	3.587e–3 (4.956e–2)	−4.104e–3 (9.616e–3)	9.272e–3 (1.870e–2)
RoofCondition Mixed	−4.804e–1*** (9.930e–2)	−1.090e–1** (3.790e–2)	−1.843e–1*** (3.974e–2)
RoofCondition Poor	–	−1.812e–1 (1.543e–1)	2.334e–2 (1.474e–1)
View – Has view	1.037e–1 (6.841e–2)	2.768e–2 (2.552e–2)	4.307e–2† (2.235e–2)
WallCondition Fair	−2.271e–2 (1.881e–1)	−6.387e–2 (6.601e–2)	−2.066e–2 (5.095e–2)
WallCondition Good	2.197e–2 (4.873e–2)	7.225e–3 (2.360e–2	2.401e–2 (1.864e–2)
WallCondition Mixed	NA	NA	NA
WallCondition Poor	-	−5.496e–2 (1.537e–1)	NA
Dist. CBD	−4.302e–2*** (9.835e–3)	−1.597e–2*** (4.585e–3)	−2.910e–2*** (3.697e–3)
Dist. to Secondary	6.753e–2*** (1.248e–2)	2.738e–2*** (5.788e–3)	4.342e–2*** (4.847e–3)
TC2	−1.272e–1** (4.792e–2)	−2.129e–2 (2.102e–2)	−5.473e–2*** (1.659e–2)
TC3	−2.474e–1*** (5.107e-2)	−4.581e–2*(2.215e–2)	−4.065e–2* (1.789e–2)
Age Purchased	−2.146e–3 (2.102e–3)	−7.461e–3*** (8.331e–4)	−4.969e–3*** (6.875e–4)
(Age Purchased)^2	1.900e–5 (1.698e–5)	6.050e–5*** (7.117e–6)	4.010e–5*** (5.786e–6)
NZ Deprivation Score	−7.997e–4*** (1.818e–4)	−6.447e–4*** (8.399e–5)	−6.413e–4*** (6.813e–5)
Burnside	−1.354e–3 (9.992e–2)	1.085e–1** (4.094e–2)	2.100e–2 (3.449e–2)
BurnsideCHCBoys	1.589e–1 (1.418e–1)	3.011e–1*** (5.826e–2)	2.269e–1*** (4.709e–2)
BurnsideCHCBoysGirls	–	–	1.985e–1 (1.529e–1)
Cashmere	4.118e–2 (5.539e–2)	1.018e–1*** (2.204e–2)	6.988e–2*** (1.930e–2)
CHCBoys	1.356e–1 (1.413e–1)	2.277e–1*** (6.595e–2)	1.340e–1** (4.884e–2)
CHCGirlsBoys	3.945e–1** (1.289e–1)	4.478e–1*** (5.480e–2)	4.010e–1*** (4.461e–2)
Riccarton	−7.905e–2 (9.768e–2)	2.827e–2 (4.030e–2)	−6.785e–3 (3.288e–2)
RiccartonCHCBoys	–	3.320e–1* (1.574e–1)	–
RiccartonCHCGirlsBoys	–	–	3.681e–1* (1.527e–1)
Burwood	−3.579e–3 (3.608e–2)	−6.371e–2*** (1.647e–2)	−7.046e–2*** (1.366e–2)
Fendalton	2.001e–1 (1.218e–1)	1.161e–1* (5.051e–2)	1.777e–1*** (4.121e–2)
Linwood	−1.057e–1* (5.299e–2)	−1.012e–1*** (2.715e–2)	−1.255e–1 *** (2.142e–2)
Papanui	5.857e–2 (3.717e–2)	4.930e–2** (1.784e–2)	6.415e–2*** (1.498e–2)
Riccarton	1.441e–1 (1.011e–1)	5.760e–2 (4.362e–2)	1.009e–12** (3.645e–2)
Spreydon	2.075e–2 (4.384e–2)	1.575e–2 (2.369e–2)	8.456e–3 (1.917e–2)
Waimairi	7.987e–2 (9.164e–2)	4.538e–2 (3.733e–2)	8.145e–2** (3.193e–2)
Degrees of Freedom	316	1055	1474
$R^2$	0.751	0.808	0.823
$R^2$ adjusted	0.726	0.802	0.819
F–statistic	30.77	126.7	195.9

Table of coefficients for the model in different time periods. The legends ’***’ indicate significance at a 0.001 level, ’**’ indicates significance at a 0.01 level, ’*’ indicates significance at a 0.05 level, and ’†’ indicates significance at a 0.1 level.

Figure 1. Net effect of age on the property price. Shows the effect of age in the depreciation of the property, and also shows the presence of the vintage effect.

Table A1. Input data for post-lockdown period $\mathit{n}=1510$.

Variable	Data Type	Min	Max	Mean	Std. Dev.
Log Real Price	Floating point	4.709	7.610	5.294	0.343
Bedrooms	Integer	1	7	–	0.782
Bathooms	Integer	1	3	–	0.604
Toilets	Integer	1	6	–	0.802
Carparks	Integer	1	8	–	1.870
Floor Area	Floating Point	68.0${\mathrm{m}}^2$	563.0${\mathrm{m}}^2$	163.015${\mathrm{m}}^2$	66.0
Land Area	Floating Point	217.0${\mathrm{m}}^2$	2611.0${\mathrm{m}}^2$	693.9${\mathrm{m}}^2$	211.386
Roof Condition	Categorical	–	–	–	–
View from Property	Categorical	–	–	–	–
Wall Condition	Categorical	–	–	–	–
Dist. CBD	Floating point	1.579$\mathrm{km}$	14.301$\mathrm{km}$	7.3$\mathrm{km}$	1.990
Dist. to Secondary	Floating point	0.085$\mathrm{km}$	9.874$\mathrm{km}$	1.741$\mathrm{km}$	1.209
Technical Category	Categorical	–	–	–	–
Age Purchased	Integer	0	121	50.39	25.711
NZ Deprivation Score	Integer	839	1365	969.4	70.113
School Zone	Categorical	–	–	–	–
Ward	Categorical	–	–	–
(Age Purchased)^2	Integer	0	14641	3199.708	2790.211

Table A2. Input data for 2014–2015 $\mathit{n}=349$.

Variable	Data Type	Min	Max	Mean	Std. Dev.
Log Real Price	Floating point	4.728	6.794	5.497	0.346
Bedrooms	Integer	2	6	–	0.751
Bathooms	Integer	1	3	–	0.628
Toilets	Integer	1	4	–	0.793
Carparks	Integer	1	5	–	0.604
Floor Area	Floating Point	80.0${\mathrm{m}}^2$	430.0${\mathrm{m}}^2$	153.1${\mathrm{m}}^2$	62.199
Land Area	Floating Point	284.0${\mathrm{m}}^2$	2529.0${\mathrm{m}}^2$	686.5${\mathrm{m}}^2$	176.013
Position of Property	Categorical	–	–	–	–
Roof Condition	Categorical	–	–	–	–
View from Property	Categorical	–	–	–	–
Wall Condition	Categorical	–	–	–	–
Dist. CBD	Floating point	1.888$\mathrm{km}$	11.766$\mathrm{km}$	5.860$\mathrm{km}$	1.914
Dist. to Secondary	Floating point	0.097$\mathrm{km}$	8.762$\mathrm{km}$	1.665$\mathrm{km}$	1.272
Technical Category	Categorical	–	–	–	–
Age Purchased	Integer	2	120	52.47	24.103
NZ Deprivation Score (2013)	Integer	855	1286	958.1	70.170
School Zone	Categorical	–	–	–	–
Ward	Categorical	–	–	–
(Age Purchased)^2	Integer	0	14161	332.372	2641.848

Table A3. Summary statistics of the estimates for $f_{\beta }$ for the pre-lockdown period.

Regressors	$\mathit{E}({\beta }_0)$	$\mathit{E}({\beta }_1)$	$\mathit{E}({\beta }_2)$	${\rho }_{{\beta }_1,{\beta }_2}$
Floor Area ($X_1$), Age at Purchase ($X_2$)	3.787e-1	1.289e-2	3.753e-4	0.407
Floor Area ($X_1$), Land Area ($X_2$)	3.406e-1	1.787e-3	3.637e-3	−0.318

Table A4. Summary statistics of the estimates for $f_{\beta }$ for the pre-lockdown period.

Regressors	$\mathit{E}({\beta }_0)$	$\mathit{E}({\beta }_1)$	$\mathit{E}({\beta }_2)$	${\rho }_{{\beta }_1,{\beta }_2}$
Floor Area ($X_1$), Age at Purchase ($X_2$)	3.271e-1	1.494e-2	6.897e-4	0.380
Floor Area ($X_1$), Land Area ($X_2$)	2.312e-1	1.460e-3	2.878e-3	−0.331

Figure A1. Contour plots of joint marginal distributions of ${\hat{f}}_{\mathit{\beta }}$ with floor area and land area having random effects: ${\hat{f}}_{{\beta }_0,{\beta }_1}$ (left), ${\hat{f}}_{{\beta }_0,{\beta }_2}$ (middle), ${\hat{f}}_{{\beta }_1,{\beta }_2}$ (right) pre-lockdown.

Figure A2. Contour plots of joint marginal distributions of ${\hat{f}}_{\mathit{\beta }}$ with floor area and land area having random effects: ${\hat{f}}_{{\beta }_0,{\beta }_1}$ (left), ${\hat{f}}_{{\beta }_0,{\beta }_2}$ (middle), ${\hat{f}}_{{\beta }_1,{\beta }_2}$ (right) post-lockdown.

Figure A3. Contour plots of joint marginal distributions of ${\hat{f}}_{\mathit{\beta }}$ with floor area and age at purchase having random effects: ${\hat{f}}_{{\beta }_0,{\beta }_1}$ (left), ${\hat{f}}_{{\beta }_0,{\beta }_2}$ (middle), ${\hat{f}}_{{\beta }_1,{\beta }_2}$ (right) pre-lockdown.

Figure A4. Contour plots of joint marginal distributions of ${\hat{f}}_{\mathit{\beta }}$ with floor area and age at purchase having random effects: ${\hat{f}}_{{\beta }_0,{\beta }_1}$ (left), ${\hat{f}}_{{\beta }_0,{\beta }_2}$ (middle), ${\hat{f}}_{{\beta }_1,{\beta }_2}$ (right) post-lockdown.

Table A5. Hedonic regression estimates by time period with quarterly time dummies.

Variable	2014–2016	2019–2020	2020–2021
	Coefficient (SE)	Coefficient (SE)	Coefficient (SE)
Intercept	1.381*** (2.241e-1)	1.347*** (1.664e-1)	1.361*** (8.197e-2)
Quarter 2	–	−3.952e–2 (2.755e–2)	−1.201e–1*** (1.148e–2)
Quarter 3	–	−1.434e–2 (1.546e–2)	−7.595e–2*** (1.099e–2)
Quarter 4	–	−9.093e–4 (1.094e–2)	−1.468e–3 (1.047e–2)
Quarter 1–2015	−5.323e–3 (4.677e–2)	–	–
Quarter 2–2014	−5.595e–2 (4.709e–2)	–	–
Quarter 2–2015	−3.348e–2 (4.420e–2)	–	-
Quarter 3–2014	−5.264e–3 (4.483e–2)	–	–
Quarter 3–2015	−2.400e–2 (4.525e–2)	–	–
Quarter 4–2014	−1.940e–2 (4.343e–2)	–	–
Quarter 4–2015	3.946e–2 (4.616e–2)	–	–
Bedrooms	1.319e–2 (3.197e–2)	−5.517e–3 (1.135e–2)	−5.443e–2*** (1.054e–2)
Bathrooms	−2.323e–2 (3.943e–2)	5.672e-3 (1.608e-2)	2.139e–2 † (1.290e–2)
Toilets	5.570e–3 (3.605e–2)	2.252e–2 (1.338e–2)	3.162e–2** (1.081e–2)
Carparks	3.271e–3 (2.089e–2)	3.585e–3 (9.361e–3)	4.090e–3 (7.016e–3)
Floor Area	2.943e–3***(3.950e–4)	2.203e–3*** (1.572e–4)	2.370e–3*** (1.276e–4)
Land Area	2.491e–4 (7.209e–5)	2.103e–4***(2.590e–5)	2.633e-4*** (2.180e-5)
RoofCondition Fair	2.079e–1 (2.475e–1)	2.958e–2 (7.482e–2)	−3.199e–2 (6.465e–2)
RoofCondition Good	−1.970e–2 (5.770e–2)	−2.847e–3 (2.364e–2)	1.134e–2 (1.896e–2)
RoofCondition Mixed	−5.561e–1*** (1.113e–1)	−1.127e–1** (3.809e–2)	−1.824e–1*** (4.058e–2)
RoofCondition Poor	–	−1.936e–1 (1.551e–1)	9.099e–3 (1.505e–1)
View – Has view	3.914e–2 (7.063e–2)	2.002e–2 (2.567e–2)	4.182e–2† (2.280e–2)
WallCondition Fair	−2.015e–1 (2.045e–1)	−8.691e–2 (6.663e–2)	−3.115e–2 (5.202e–2)
WallCondition Good	4.621e–2 (5.669e–2)	7.452e–3 (2.365e–2)	2.401e–2 (1.864e–2)
WallCondition Mixed	NA	NA	NA
WallCondition Poor	–	−8.832e–2 (1.547e–1)	NA
Dist. CBD	−4.389e–2*** (9.276e–3)	−1.632e–2*** (4.454e–3)	−2.713e–2*** (3.711e–3)
Dist. to Secondary	3.514e–2** (1.298e–2)	2.858e–2*** (5.767e–3)	4.112e–2*** (4.949e–3)
TC2	−4.404e–2 (3.399e–2)	−3.071e–2 (1.894e–2)	−4.129e–2** (1.567e–2)
TC3	−1.560e–1*** (3.943e–2)	−5.321e–2** (2.024e–2)	−2.798e–2 (1.711e–2)
Age Purchased	−6.723e–3** (2.206e–3)	−7.117e–3*** (8.395e–4)	−5.208e–3*** (7.137e–4)
(Age Purchased)^2	6.472e–5*** (1.899e–5)	5.841e–5*** (7.160e–6)	4.383e–5*** (5.999e–6)
NZ Deprivation Score	−8.780e–4*** (1.893e–4)	−6.433e–4*** (8.427e–5)	−6.206e–4*** (6.974e–5)
Burnside	−8.311e–2 (2.126e–1)	9.399e–2*** (2.577e–2)	3.261e–2 (2.217e–2)
BurnsideCHCBoys	4.097e–1† (2.116e–1)	2.914e–1*** (4.768e–2)	2.074e–1*** (3.975e–2)
BurnsideCHCBoysGirls	–	–	11.976e–1 (1.536e–1)
Cashmere	−1.624e–1 (1.247e–1)	9.841e–2*** (2.210e–2)	6.181e–2** (1.973e–2)
CHCBoys	−1.058e–2 (2.204e–1)	2.210e–1*** (5.415e–2)	1.356e–1** (4.247e–2)
CHCGirlsBoys	6.225e–1*** (1.305e–1)	4.331e–1*** (4.265e–2	3.938e–1*** (3.582e–2)
Riccarton	−1.016e–3 (3.112e–1)	2.827e–2 (4.030e–2)	–
RiccartonCHCBoys	–	3.320e–1* (1.574e–1)	–
RiccartonCHCGirlsBoys	–	–	–
Burwood	−5.058e–2 (3.608e–2)	−6.472e–2*** (1.654e–2)	−7.210e–2*** (1.393e–2)
Fendalton	–	1.214e–1** (3.975e–2)	1.878e–1*** (3.385e–2)
Linwood	−1.591e–1 (1.101e–1)	−1.034e–1*** (2.721e–2)	−1.350e–1*** (2.182e–2)
Papanui	−2.557e–2 (1.010e–1)	5.253e–2** (1.795e–2)	5.607e–2*** (1.533e–2)
Riccarton	2.063e–1 (3.678e–1)	7.751e–2* (3.064e–2)	1.066e–1*** (2.637e–2)
Spreydon	−5.600e–2 (9.363e–2)	1.570e–2 (2.378e–2)	1.510e–2 (1.964e–2)
Waimairi	1.125e–1 (2.313e–1)	5.472e–2 (2.774e–2)	8.780e–2*** (2.377e–2)
Degrees of Freedom	1054	1055	1462
$R^2$	0.7099	0.8056	0.8216
$R^2$ adjusted	0.6733	0.799	0.8172
F-statistic	19.39	121.3	187.1

Table of coefficients for the model in different time periods. The legends ’***’ indicate significance at a 0.001 level, ’**’ indicates significance at a 0.01 level, ’*’ indicates significance at a 0.05 level, and ’†’ indicates significance at a 0.1 level.

Table A6. Summary results for OLS models using suburb in place of wards as the geographical feature.

	2014–2016	2019–2020	2020–2021
Degrees of Freedom	267	1001	1407
R-squared	0.8378	0.8389	0.8594
Adj R-squared	0.7886	0.8246	0.8503
F-Statistic	17.03	58.56	94.51

Table A7. Contigency table for suburb and technical category for each time period.

	2014–2016			2019–2020			2020–2021
Suburb	TC1	TC2	TC3	TC1	TC2	TC3	TC1	TC2	TC3
Aidanfield	0	2	0	0	9	0	0	18	0
Aranui	0	2	3	0	11	10	0	15	14
Avondale	0	3	2	0	1	13	0	4	22
Avonhead	13	0	0	49	0	0	66	0	0
Avonside	0	3	3	0	6	3	0	5	3
Beckenham	0	1	0	0	8	0	0	9	2
Belfast	0	3	0	0	8	0	0	7	1
Bishopdale	2	13	1	8	25	1	16	37	3
Bromley	0	2	0	0	9	0	0	13	0
Broomfield	6	0	0	8	0	0	14	0	0
Bryndwr	2	7	0	3	25	0	6	37	0
Burnside	13	1	0	34	10	1	58	7	1
Burwood	0	6	7	0	25	26	0	27	36
Casebrook	0	7	1	0	23	3	0	34	5
Cashmere	0	2	1	0	9	3	0	6	0
Cracroft				0	1	0	0	1	0
Dallington	0	2	5	0	5	4	0	10	10
Fendalton	0	6	1	0	10	10	0	30	6
Halswell	0	15	2	0	64	6	0	70	6
Harewood				2	13	0	0	14	0
Heathcote Valley	0	2	0	0	8	0	0	6	0
Hei Hei	6	0	0	17	0	0	16	0	0
Hillmorton	0	6	1	0	13	3	0	21	3
Hillsborough	0	2	0	0	5	1	0	8	1
Hoon Hay	0	20	0	0	33	0	0	50	2
Hornby	14	0	0	30	0	0	38	0	0
Huntsbury							0	1	0
Ilam	7	4	0	17	11	0	33	20	0
Islington	1	0	0	6	0	0	9	0	0
Kainga							0	1	0
Linwood	0	3	2	0	6	4	0	11	5
Mairehau	0	8	1	0	19	8	0	30	9
Merivale	0	0	4	0	3	11	0	2	14
Mount Pleasant				0	3	0	0	3	0
New Brighton	0	3	3	0	8	19	0	19	24
North New Brighton	0	4	2	0	7	8	0	14	11
Northcote	0	3	0	0	9	0	0	11	0
Northwood	0	2	2	0	12	4	0	15	9
Opawa	0	0	2	0	1	6	0	4	7
Papanui	0	7	0	0	17	0	0	38	0
Parklands	0	4	9	0	23	43	0	28	44
Redcliffs	0	1	0	0	2	1	0	3	2
Redwood	0	16	0	0	54	1	0	53	1
Riccarton				0	7	0	0	6	0
Richmond	0	0	3	0	2	8	0	2	13
Russley	5	0	0	14	0	0	15	0	0
Saint Martins	0	3	1	0	6	6	0	11	8
Shirley	0	11	2	0	18	2	0	31	3
Sockburn	2	0	0	18	0	0	18	0	0
Somerfield	0	2	0	0	19	0	0	9	0
South New Brighton	0	2	0	0	7	2	0	11	3
Southshore	0	0	1	0	4	6	0	3	2
Spreydon	0	2	0	0	6	0	0	3	0
St Albans	0	4	6	0	7	10	0	20	20
Strowan	0	6	0	0	9	1	0	23	3
Sumner	0	4	0	0	4	0	0	10	0
Sydenham				0	3	0	0	3	0
Templeton				4	0	0	12	0	0
Upper Riccarton	3	1	0	8	6	0	6	8	0
Waimairi Beach	0	2	0	0	8	0	0	7	0
Wainoni	0	0	5	0	2	8	0	6	9
Westmorland							0	1	0
Wigram	1	0	0	8	0	0	15	0	0
Woolston	0	3	4	0	16	8	0	25	12
Yaldhurst				2	0	0	2	0	0
Moncks Bay				0	3	0