{
  "source": "Statistics Bureau of Japan, 2023 Housing and Land Survey final table; MLIT 2026 Land Price Publication",
  "prefectures": 47,
  "method": "Centered log-ratio transform of four vacancy composition shares, followed by PCA; land-price growth is an external descriptor, not an input to PCA.",
  "explained_variance_percent": [
    78.59,
    17.73,
    3.68
  ],
  "first_two_total_percent": 96.32,
  "loadings": {
    "pc1": {
      "rent_share": -0.3001,
      "sale_share": -0.4344,
      "second_share": 0.8424,
      "other_share": -0.1079
    },
    "pc2": {
      "rent_share": -0.2454,
      "sale_share": -0.4161,
      "second_share": -0.1926,
      "other_share": 0.8541
    },
    "pc3": {
      "rent_share": 0.7744,
      "sale_share": -0.623,
      "second_share": -0.0574,
      "other_share": -0.094
    }
  },
  "correlations": {
    "pc1": {
      "vacancy_rate": {
        "rho": 0.4335,
        "p": 0.0023344976804905416
      },
      "excluded_rate": {
        "rho": 0.2185,
        "p": 0.13998450005186092
      },
      "land_rate_2026": {
        "rho": -0.33,
        "p": 0.023512435384834846
      }
    },
    "pc2": {
      "vacancy_rate": {
        "rho": 0.5602,
        "p": 4.219777286195254e-05
      },
      "excluded_rate": {
        "rho": 0.8855,
        "p": 1.3855306668436212e-16
      },
      "land_rate_2026": {
        "rho": -0.477,
        "p": 0.000699295871081697
      }
    }
  },
  "leave_one_prefecture_out": {
    "first_two_variance_percent_range": [
      95.6,
      97.07
    ],
    "pc2_land_rate_rho_range": [
      -0.5038,
      -0.4445
    ]
  },
  "extremes": {
    "pc1_high": [
      "長野県",
      "山梨県",
      "新潟県",
      "静岡県",
      "栃木県"
    ],
    "pc1_low": [
      "東京都",
      "宮城県",
      "福岡県",
      "大阪府",
      "愛知県"
    ],
    "pc2_high": [
      "秋田県",
      "鹿児島県",
      "島根県",
      "宮崎県",
      "高知県"
    ],
    "pc2_low": [
      "東京都",
      "神奈川県",
      "静岡県",
      "千葉県",
      "北海道"
    ]
  },
  "limits": [
    "PCA describes variation in aggregate composition; it is not a causal model or a stable policy typology.",
    "Prefectures are equally weighted; counts, population, land area, and transactions do not weight the axes.",
    "Housing composition is from 2023 and land-price change from 2026; association does not identify direction or cause."
  ]
}