{
  "metadata": {
    "title": "Comparison of three response curves",
    "status": "illustrative data",
    "units": {
      "spend": "thousand EUR",
      "incremental_effect": "thousand EUR"
    }
  },
  "observations": [
    {
      "spend": 0,
      "effect": 0
    },
    {
      "spend": 50,
      "effect": 49
    },
    {
      "spend": 100,
      "effect": 79
    },
    {
      "spend": 150,
      "effect": 97
    },
    {
      "spend": 200,
      "effect": 108
    }
  ],
  "models": {
    "linear": {
      "formula": "y = beta * x",
      "parameters": {
        "beta": 0.62
      },
      "predictions": [
        0,
        31,
        62,
        93,
        124
      ],
      "slope_at_200": 0.62,
      "status": "rejected for extrapolation"
    },
    "exponential": {
      "formula": "y = A * (1 - exp(-b * x))",
      "parameters": {
        "A": 125,
        "b": 0.01
      },
      "predictions": [
        0,
        49.18,
        79.02,
        97.11,
        108.08
      ],
      "slope_at_200": 0.1692,
      "status": "retained"
    },
    "hill": {
      "formula": "y = A * x^s / (k^s + x^s)",
      "parameters": {
        "A": 130,
        "k": 70,
        "s": 1.4
      },
      "predictions": [
        0,
        49.97,
        80.9,
        96.72,
        105.69
      ],
      "status": "sensitivity"
    }
  }
}