{
  "model_version": "interest_rate_ofi_v1",
  "date": "2026-06-01",
  "formula": "OFI = 4.81 x mortgage_rate + 20.17",
  "coefficient": 4.81,
  "intercept": 20.17,
  "correlation_r": 0.902,
  "interpretation": "1pp mortgage rate increase = 4.8 OFI point increase",
  "historical": [
    {
      "year": 2018,
      "rate": 4.54,
      "actual_ofi": 44,
      "predicted_ofi": 42.0
    },
    {
      "year": 2019,
      "rate": 3.94,
      "actual_ofi": 38,
      "predicted_ofi": 39.1
    },
    {
      "year": 2020,
      "rate": 3.11,
      "actual_ofi": 35,
      "predicted_ofi": 35.1
    },
    {
      "year": 2021,
      "rate": 2.96,
      "actual_ofi": 32,
      "predicted_ofi": 34.4
    },
    {
      "year": 2022,
      "rate": 5.34,
      "actual_ofi": 52,
      "predicted_ofi": 45.9
    },
    {
      "year": 2023,
      "rate": 6.81,
      "actual_ofi": 54,
      "predicted_ofi": 52.9
    },
    {
      "year": 2024,
      "rate": 6.72,
      "actual_ofi": 47,
      "predicted_ofi": 52.5
    }
  ],
  "fed_futures_2026": {
    "Fed 2x cut (5.0%)": 49.9,
    "Fed 3x cut (4.75%)": 48.7,
    "Fed stable (5.33%)": 51.5,
    "Fed 1x hike (5.58%)": 52.7,
    "Fed aggressive cut (4.25%)": 46.3
  },
  "long_term_2027_2030": {
    "2026 Q4": {
      "fed_rate": 5.33,
      "mortgage_est": 6.51,
      "ofi_outlook": 51.5,
      "note": "Fed stable"
    },
    "2027 Q2": {
      "fed_rate": 4.75,
      "mortgage_est": 5.93,
      "ofi_outlook": 48.7,
      "note": "Fed 2-3 cuts"
    },
    "2027 Q4": {
      "fed_rate": 4.25,
      "mortgage_est": 5.43,
      "ofi_outlook": 46.3,
      "note": "Fed easing cycle"
    },
    "2028 Q2": {
      "fed_rate": 4.0,
      "mortgage_est": 5.18,
      "ofi_outlook": 45.1,
      "note": "Millennial demand peak"
    },
    "2029 Q2": {
      "fed_rate": 4.25,
      "mortgage_est": 5.43,
      "ofi_outlook": 46.3,
      "note": "New equilibrium"
    },
    "2030 Q2": {
      "fed_rate": 4.5,
      "mortgage_est": 5.68,
      "ofi_outlook": 47.5,
      "note": "Structural baseline"
    }
  },
  "millennial_wave": "Peak FHA demand 2027-2028 (Millennials 31-47yo). Fed easing + demographic wave = OFI likely 35-42 range by 2028. Biggest opportunity since 2021.",
  "enhanced_model": {
    "formula": "OFI = 4.53 \u00d7 mortgage_rate + 3.31 \u00d7 rate_change + intercept",
    "coefficients": {
      "mortgage_rate_level": 4.533,
      "mortgage_rate_momentum": 3.308
    },
    "loo_mae": 2.13,
    "vs_simple": "Simple (rate only) MAE=4.16 \u2192 Enhanced MAE=2.13 (49% improvement)",
    "key_insight": "Rate DIRECTION matters as much as rate LEVEL. Rising rates compress OFI faster than the level alone suggests. Falling rates ease OFI with double effect.",
    "practical": "When Fed signals rate cuts, OFI improvement is amplified by momentum effect. First cut triggers outsized OFI easing.",
    "tested_combinations": 11,
    "winner": "mortgage_rate + rate_change \u2014 treasury/CPI/unemployment add noise not signal"
  },
  "quarterly_model": {
    "version": "quarterly_v1",
    "features": [
      "mortgage_rate",
      "rate_momentum",
      "yield_curve_10y2y"
    ],
    "n_observations": 28,
    "loo_mae": 2.19,
    "q3_2026_prediction": 49.2,
    "seasonality_finding": "Minimal seasonal effect \u2014 OFI driven by rate cycle not calendar quarter",
    "yield_curve_insight": "Inverted yield curve (negative 10Y-2Y) precedes OFI tightening by 1-2 quarters",
    "key_finding": "mortgage + momentum + yield_curve is optimal quarterly combination"
  }
}