{
 "record_id": "a7a83b631f85316bae926a6c965b325fb26c01c4",
 "eligible": true,
 "exclusion_reason": null,
 "study": {
  "title": "A gamma generalised linear model as an alternative to log linear real estate price functions",
  "year": 2019,
  "doi": "10.4102/jef.v12i1.476",
  "country": "South Africa",
  "region_city": "South Africa (national; >2000 suburb/area factor levels)",
  "sample_start": 2013,
  "sample_end": 2017,
  "property_type": "mixed",
  "price_type": "listing",
  "data_source": "Online property portal aggregating agency listings across South Africa, Jan 2013 - Aug 2017; 415,200 listings after autoencoder anomaly removal; 70% training split",
  "document_type": "journal",
  "estimators": [
   "other"
  ],
  "spatial_method": "none (area factor dummies, >2000 levels)",
  "time_fe": false,
  "location_fe": true,
  "se_type": "unknown",
  "n_obs_total": 415200,
  "ai_methods": [
   "autoencoder (H2O) used only for anomaly detection in data cleaning"
  ],
  "notes": "Yearly cross-sectional gamma GLMs with log link (Table 4, p.9), fitted on the 70% training split; per-year n not printed. Coefficients are interpreted by the authors as percentage effects (beta x 100 %); dep_transform coded 'log' to reflect the log link (E[price]=exp(Xb)), NOT a log-transformed price. Only p-values are printed (no SE/t); p printed as '2e-9' is taken literally (likely a floor of the software output); '4-e5' in 2013 Simplex read as 4e-5. Area (suburb) factor coefficients omitted by the authors. Property-type dummies relative to apartment (reference). Listing price in ZAR (>= 200,000)."
 },
 "models": [
  {
   "model_id": "T4-2013",
   "table": "4",
   "column": "2013",
   "page": 9,
   "dep_var": "listing price (ZAR), gamma GLM log link",
   "dep_transform": "log",
   "estimator": "other",
   "n_obs": null,
   "r2": null,
   "se_or_t_in_parentheses": "p",
   "sample_subset": "Listings of year 2013 (training split 70%); gamma GLM log link; deviance explained 0.89"
  },
  {
   "model_id": "T4-2014",
   "table": "4",
   "column": "2014",
   "page": 9,
   "dep_var": "listing price (ZAR), gamma GLM log link",
   "dep_transform": "log",
   "estimator": "other",
   "n_obs": null,
   "r2": null,
   "se_or_t_in_parentheses": "p",
   "sample_subset": "Listings of year 2014 (training split 70%); gamma GLM log link; deviance explained 0.87"
  },
  {
   "model_id": "T4-2015",
   "table": "4",
   "column": "2015",
   "page": 9,
   "dep_var": "listing price (ZAR), gamma GLM log link",
   "dep_transform": "log",
   "estimator": "other",
   "n_obs": null,
   "r2": null,
   "se_or_t_in_parentheses": "p",
   "sample_subset": "Listings of year 2015 (training split 70%); gamma GLM log link; deviance explained 0.87"
  },
  {
   "model_id": "T4-2016",
   "table": "4",
   "column": "2016",
   "page": 9,
   "dep_var": "listing price (ZAR), gamma GLM log link",
   "dep_transform": "log",
   "estimator": "other",
   "n_obs": null,
   "r2": null,
   "se_or_t_in_parentheses": "p",
   "sample_subset": "Listings of year 2016 (training split 70%); gamma GLM log link; deviance explained 0.87"
  },
  {
   "model_id": "T4-2017",
   "table": "4",
   "column": "2017",
   "page": 9,
   "dep_var": "listing price (ZAR), gamma GLM log link",
   "dep_transform": "log",
   "estimator": "other",
   "n_obs": null,
   "r2": null,
   "se_or_t_in_parentheses": "p",
   "sample_subset": "Listings of year 2017 (training split 70%); gamma GLM log link; deviance explained 0.88"
  }
 ],
 "coefficients": [
  {
   "model_id": "T4-2013",
   "var_name_printed": "Log (size)",
   "taxonomy_id": "living_area",
   "x_transform": "log",
   "x_unit": "m2",
   "beta": 0.664,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "natural log of structure size in m2; elasticity; only p-value printed"
  },
  {
   "model_id": "T4-2014",
   "var_name_printed": "Log (size)",
   "taxonomy_id": "living_area",
   "x_transform": "log",
   "x_unit": "m2",
   "beta": 0.626,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "natural log of structure size in m2; elasticity; only p-value printed"
  },
  {
   "model_id": "T4-2015",
   "var_name_printed": "Log (size)",
   "taxonomy_id": "living_area",
   "x_transform": "log",
   "x_unit": "m2",
   "beta": 0.558,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "natural log of structure size in m2; elasticity; only p-value printed"
  },
  {
   "model_id": "T4-2016",
   "var_name_printed": "Log (size)",
   "taxonomy_id": "living_area",
   "x_transform": "log",
   "x_unit": "m2",
   "beta": 0.479,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "natural log of structure size in m2; elasticity; only p-value printed"
  },
  {
   "model_id": "T4-2017",
   "var_name_printed": "Log (size)",
   "taxonomy_id": "living_area",
   "x_transform": "log",
   "x_unit": "m2",
   "beta": 0.512,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "natural log of structure size in m2; elasticity; only p-value printed"
  },
  {
   "model_id": "T4-2013",
   "var_name_printed": "Bedrooms",
   "taxonomy_id": "bedrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.003,
   "se": null,
   "t": null,
   "p": 0.313,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "number of bedrooms; only p-value printed"
  },
  {
   "model_id": "T4-2014",
   "var_name_printed": "Bedrooms",
   "taxonomy_id": "bedrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.017,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "number of bedrooms; only p-value printed"
  },
  {
   "model_id": "T4-2015",
   "var_name_printed": "Bedrooms",
   "taxonomy_id": "bedrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.021,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "number of bedrooms; only p-value printed"
  },
  {
   "model_id": "T4-2016",
   "var_name_printed": "Bedrooms",
   "taxonomy_id": "bedrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.034,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "number of bedrooms; only p-value printed"
  },
  {
   "model_id": "T4-2017",
   "var_name_printed": "Bedrooms",
   "taxonomy_id": "bedrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.025,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "number of bedrooms; only p-value printed"
  },
  {
   "model_id": "T4-2013",
   "var_name_printed": "Bathrooms",
   "taxonomy_id": "bathrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.111,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "number of bathrooms; only p-value printed"
  },
  {
   "model_id": "T4-2014",
   "var_name_printed": "Bathrooms",
   "taxonomy_id": "bathrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.096,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "number of bathrooms; only p-value printed"
  },
  {
   "model_id": "T4-2015",
   "var_name_printed": "Bathrooms",
   "taxonomy_id": "bathrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.112,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "number of bathrooms; only p-value printed"
  },
  {
   "model_id": "T4-2016",
   "var_name_printed": "Bathrooms",
   "taxonomy_id": "bathrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.117,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "number of bathrooms; only p-value printed"
  },
  {
   "model_id": "T4-2017",
   "var_name_printed": "Bathrooms",
   "taxonomy_id": "bathrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.112,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "number of bathrooms; only p-value printed"
  },
  {
   "model_id": "T4-2013",
   "var_name_printed": "Cluster",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.09,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "cluster home vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2014",
   "var_name_printed": "Cluster",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.136,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "cluster home vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2015",
   "var_name_printed": "Cluster",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.146,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "cluster home vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2016",
   "var_name_printed": "Cluster",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.187,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "cluster home vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2017",
   "var_name_printed": "Cluster",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.187,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "cluster home vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2013",
   "var_name_printed": "Duplex",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.003,
   "se": null,
   "t": null,
   "p": 0.874,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "duplex vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2014",
   "var_name_printed": "Duplex",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.025,
   "se": null,
   "t": null,
   "p": 0.104,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "duplex vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2015",
   "var_name_printed": "Duplex",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.035,
   "se": null,
   "t": null,
   "p": 0.024,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "duplex vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2016",
   "var_name_printed": "Duplex",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.086,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "duplex vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2017",
   "var_name_printed": "Duplex",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.079,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "duplex vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2013",
   "var_name_printed": "House",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.027,
   "se": null,
   "t": null,
   "p": 0.0003,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "house vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2014",
   "var_name_printed": "House",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.063,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "house vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2015",
   "var_name_printed": "House",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.103,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "house vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2016",
   "var_name_printed": "House",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.158,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "house vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2017",
   "var_name_printed": "House",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.141,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "house vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2013",
   "var_name_printed": "Simplex",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.061,
   "se": null,
   "t": null,
   "p": 4e-05,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "simplex vs apartment (reference); p printed as '4-e5' (typo), read as 4e-5; only p-value printed"
  },
  {
   "model_id": "T4-2014",
   "var_name_printed": "Simplex",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.068,
   "se": null,
   "t": null,
   "p": 5e-07,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "simplex vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2015",
   "var_name_printed": "Simplex",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.078,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "simplex vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2016",
   "var_name_printed": "Simplex",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.117,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "simplex vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2017",
   "var_name_printed": "Simplex",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.087,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "simplex vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2013",
   "var_name_printed": "Townhouse",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.05,
   "se": null,
   "t": null,
   "p": 0.064,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "townhouse vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2014",
   "var_name_printed": "Townhouse",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.063,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "townhouse vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2015",
   "var_name_printed": "Townhouse",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.077,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "townhouse vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2016",
   "var_name_printed": "Townhouse",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.09,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "townhouse vs apartment (reference); only p-value printed"
  },
  {
   "model_id": "T4-2017",
   "var_name_printed": "Townhouse",
   "taxonomy_id": "dwelling_type",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.099,
   "se": null,
   "t": null,
   "p": 2e-09,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 9,
   "confidence": "high",
   "notes": "townhouse vs apartment (reference); only p-value printed"
  }
 ]
}