{
 "record_id": "b922ab81201881b47779769df9e76de174e13df7",
 "eligible": true,
 "exclusion_reason": null,
 "study": {
  "title": "Comparing traditional and machine learning techniques in apartments mass appraisal in Fortaleza, Brazil",
  "year": 2025,
  "doi": "10.36253/aestim-15344",
  "country": "Brazil",
  "region_city": "Fortaleza (Ceará)",
  "sample_start": 2017,
  "sample_end": 2021,
  "property_type": "condo_apartment",
  "price_type": "transaction_and_listing",
  "data_source": "Real Estate Market Observatory of the Local Finance Secretary of Fortaleza: 43,585 apartment listed prices and actual sales 2017-2021; training set 32,688 used for the regressions (test set 10,897)",
  "document_type": "journal",
  "estimators": [
   "OLS",
   "spatial_error"
  ],
  "spatial_method": "spatial error model (GMM, Arraiz et al. 2010), queen contiguity weights",
  "time_fe": true,
  "location_fe": false,
  "se_type": "unknown",
  "n_obs_total": 32688,
  "ai_methods": [
   "MARS",
   "M5P",
   "random_forest",
   "quantile_random_forest",
   "GBM",
   "LightGBM",
   "CatBoost",
   "XGBoost",
   "deep_learning"
  ],
  "notes": "Aestimum 86 (2025). Table A1 reports coefficients of the OLS (MRA) and spatial error (SER, GMM) models; no SEs: '*' = p-value < 0.01, otherwise the p-value is printed in parentheses. Dependent variable ln(price) in BRL; sample mixes asking and sale prices with 'sale' and 'listing' dummies (extracted as 'other'). Year dummies a2018-a2021 not extracted. Table A2 (MARS hinge-function coefficients) and ML models (feature importance only) not extracted. Normalised coordinates xcen/ycen listed in Table 2 do not appear in Table A1."
 },
 "models": [
  {
   "model_id": "TA1-MRA",
   "table": "A1",
   "column": "MRA (OLS)",
   "page": 16,
   "dep_var": "ln(price, BRL)",
   "dep_transform": "log",
   "estimator": "OLS",
   "n_obs": 32688,
   "r2": 0.9386,
   "se_or_t_in_parentheses": "p",
   "sample_subset": "Training set"
  },
  {
   "model_id": "TA1-SER",
   "table": "A1",
   "column": "SER (GMM)",
   "page": 16,
   "dep_var": "ln(price, BRL)",
   "dep_transform": "log",
   "estimator": "spatial_error",
   "n_obs": 32688,
   "r2": 0.938,
   "se_or_t_in_parentheses": "p",
   "sample_subset": "Training set; lambda = 0.6389*"
  }
 ],
 "coefficients": [
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "parcelarea",
   "taxonomy_id": "lot_size",
   "x_transform": "level",
   "x_unit": "m2",
   "beta": -1.24e-05,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "proportional land-plot area attributed to the apartment (ideal fraction), m2; '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "parcelarea",
   "taxonomy_id": "lot_size",
   "x_transform": "level",
   "x_unit": "m2",
   "beta": -1.26e-05,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "proportional land-plot area attributed to the apartment (ideal fraction), m2; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "income",
   "taxonomy_id": "income",
   "x_transform": "level",
   "x_unit": "multiples of Brazilian minimum wage",
   "beta": 0.012,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "mean income of head of family in the census sector, in minimum wages; '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "income",
   "taxonomy_id": "income",
   "x_transform": "level",
   "x_unit": "multiples of Brazilian minimum wage",
   "beta": 0.0118,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "mean income of head of family in the census sector, in minimum wages; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "vertdens",
   "taxonomy_id": "density",
   "x_transform": "level",
   "x_unit": "index",
   "beta": 0.183,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "verticalization density (concentration of units in neighbourhood), 0-1; '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "vertdens",
   "taxonomy_id": "density",
   "x_transform": "level",
   "x_unit": "index",
   "beta": 0.1919,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "verticalization density (concentration of units in neighbourhood), 0-1; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "distpv",
   "taxonomy_id": "neighbourhood_amenities",
   "x_transform": "level",
   "x_unit": "m",
   "beta": -8.4e-06,
   "se": null,
   "t": null,
   "p": 0.0137,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "nearest distance to main urban amenities; p-value printed in parentheses"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "distpv",
   "taxonomy_id": "neighbourhood_amenities",
   "x_transform": "level",
   "x_unit": "m",
   "beta": -1.09e-05,
   "se": null,
   "t": null,
   "p": 0.1556,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "nearest distance to main urban amenities; p-value printed in parentheses"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "distassp",
   "taxonomy_id": "other",
   "x_transform": "level",
   "x_unit": "m",
   "beta": 4.88e-05,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "distance to the nearest precarious settlement (informal settlement); '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "distassp",
   "taxonomy_id": "other",
   "x_transform": "level",
   "x_unit": "m",
   "beta": 3.93e-05,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "distance to the nearest precarious settlement (informal settlement); '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "distbm",
   "taxonomy_id": "water_proximity",
   "x_transform": "level",
   "x_unit": "m",
   "beta": -1.34e-05,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "distance to the beach (north of the city); '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "distbm",
   "taxonomy_id": "water_proximity",
   "x_transform": "level",
   "x_unit": "m",
   "beta": -1.49e-05,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "distance to the beach (north of the city); '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "elev",
   "taxonomy_id": "accessibility",
   "x_transform": "binary",
   "x_unit": "binary",
   "beta": 0.0372,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "presence of elevator(s); '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "elev",
   "taxonomy_id": "accessibility",
   "x_transform": "binary",
   "x_unit": "binary",
   "beta": 0.0488,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "presence of elevator(s); '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "pool",
   "taxonomy_id": "pool",
   "x_transform": "binary",
   "x_unit": "binary",
   "beta": 0.1085,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "; '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "pool",
   "taxonomy_id": "pool",
   "x_transform": "binary",
   "x_unit": "binary",
   "beta": 0.0938,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "nfloors",
   "taxonomy_id": "storeys",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.0104,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "total number of floors in the building; '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "nfloors",
   "taxonomy_id": "storeys",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.0103,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "total number of floors in the building; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "standard3",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.0989,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 3 (economical); ordinal 1 rustic ... 8 luxury; '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "standard3",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.1833,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 3 (economical); ordinal 1 rustic ... 8 luxury; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "standard4",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.3631,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 4 (simple); '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "standard4",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.3979,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 4 (simple); '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "standard5",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.5058,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 5 (medium); '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "standard5",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.5163,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 5 (medium); '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "standard6",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.689,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 6 (superior); '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "standard6",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.6667,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 6 (superior); '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "standard7",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.8583,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 7 (fine); '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "standard7",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.8574,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 7 (fine); '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "standard8",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 1.1789,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 8 (luxury); '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "standard8",
   "taxonomy_id": "condition",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 1.1219,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "finishing standard 8 (luxury); '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "bedroom",
   "taxonomy_id": "bedrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.0084,
   "se": null,
   "t": null,
   "p": 0.0015,
   "p_stars": "",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "; p-value printed in parentheses"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "bedroom",
   "taxonomy_id": "bedrooms",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.0163,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "garage",
   "taxonomy_id": "garage",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.0317,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "number of garage spaces; '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "garage",
   "taxonomy_id": "garage",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.0305,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "number of garage spaces; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "ln_privarea",
   "taxonomy_id": "living_area",
   "x_transform": "log",
   "x_unit": "m2",
   "beta": 0.368,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "private (exclusive) area of the apartment; '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "ln_privarea",
   "taxonomy_id": "living_area",
   "x_transform": "log",
   "x_unit": "m2",
   "beta": 0.367,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "private (exclusive) area of the apartment; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "ln_totalarea",
   "taxonomy_id": "other",
   "x_transform": "log",
   "x_unit": "m2",
   "beta": 0.3021,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "ln_totalarea: total area incl. share of common areas (second area measure alongside private area); '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "ln_totalarea",
   "taxonomy_id": "other",
   "x_transform": "log",
   "x_unit": "m2",
   "beta": 0.3061,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "ln_totalarea: total area incl. share of common areas (second area measure alongside private area); '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "lastfloor",
   "taxonomy_id": "floor_level",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.0689,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "top-floor dummy; '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "lastfloor",
   "taxonomy_id": "floor_level",
   "x_transform": "dummy",
   "x_unit": "binary",
   "beta": 0.0799,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "top-floor dummy; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "floor",
   "taxonomy_id": "floor_level",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.0065,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "apartment floor; '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "floor",
   "taxonomy_id": "floor_level",
   "x_transform": "level",
   "x_unit": "count",
   "beta": 0.0065,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "apartment floor; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "age",
   "taxonomy_id": "age",
   "x_transform": "level",
   "x_unit": "years",
   "beta": -0.0097,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "; '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "age",
   "taxonomy_id": "age",
   "x_transform": "level",
   "x_unit": "years",
   "beta": -0.0098,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "; '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "sale",
   "taxonomy_id": "other",
   "x_transform": "binary",
   "x_unit": "binary",
   "beta": -0.0626,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "sale: effective sale dummy (transaction vs other record types); '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "sale",
   "taxonomy_id": "other",
   "x_transform": "binary",
   "x_unit": "binary",
   "beta": -0.0759,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "sale: effective sale dummy (transaction vs other record types); '*' = p<0.01"
  },
  {
   "model_id": "TA1-MRA",
   "var_name_printed": "listing",
   "taxonomy_id": "other",
   "x_transform": "binary",
   "x_unit": "binary",
   "beta": 0.0528,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "listing: asking-price dummy (1 = list price, 0 = sale price); '*' = p<0.01"
  },
  {
   "model_id": "TA1-SER",
   "var_name_printed": "listing",
   "taxonomy_id": "other",
   "x_transform": "binary",
   "x_unit": "binary",
   "beta": 0.0407,
   "se": null,
   "t": null,
   "p": null,
   "p_stars": "*",
   "ci_lo": null,
   "ci_hi": null,
   "page": 16,
   "confidence": "high",
   "notes": "listing: asking-price dummy (1 = list price, 0 = sale price); '*' = p<0.01"
  }
 ]
}