{
  "id": "negative-consumption-externality",
  "name": "Negative consumption externality",
  "unit": "micro",
  "unitName": "Unit 2 · Microeconomics",
  "topic": "Market failure",
  "hl": false,
  "description": "Consumption imposes external costs on others (e.g. smoking, alcohol), so MSB lies below MPB and the free market over-consumes: Q_m > Q*, creating a welfare loss.",
  "keywords": [
    "negative externality",
    "consumption externality",
    "demerit good",
    "external cost",
    "MSB",
    "MPB",
    "overconsumption",
    "over-allocation",
    "welfare loss",
    "indirect tax",
    "sin tax",
    "education"
  ],
  "schemaUrl": "https://graphs.lectere.com/api/v1/templates/negative-consumption-externality",
  "previewUrl": "https://graphs.lectere.com/thumbs/negative-consumption-externality.svg",
  "editorUrl": "https://graphs.lectere.com/graph/negative-consumption-externality/",
  "params": [
    {
      "key": "policy",
      "label": "Government response",
      "default": "none",
      "type": "enum",
      "options": [
        {
          "value": "none",
          "label": "None"
        },
        {
          "value": "tax",
          "label": "Indirect tax"
        },
        {
          "value": "education",
          "label": "Education / negative advertising"
        }
      ]
    },
    {
      "key": "dwl",
      "label": "Shade welfare loss",
      "default": true,
      "type": "boolean"
    },
    {
      "key": "marker",
      "label": "Mark the external cost",
      "default": true,
      "type": "boolean"
    },
    {
      "key": "shape",
      "label": "Social curve",
      "default": "parallel",
      "group": "Shape",
      "type": "enum",
      "options": [
        {
          "value": "parallel",
          "label": "Parallel (constant externality per unit)"
        },
        {
          "value": "diverging",
          "label": "Diverging (externality grows with output)"
        }
      ]
    },
    {
      "key": "ext",
      "label": "Size of external cost",
      "default": 2,
      "group": "Shape",
      "type": "number",
      "min": 0.6,
      "max": 3.5,
      "step": 0.1
    },
    {
      "key": "dSlope",
      "label": "Demand steepness",
      "default": 0.8,
      "group": "Shape",
      "type": "number",
      "min": 0.3,
      "max": 2.5,
      "step": 0.05
    },
    {
      "key": "sSlope",
      "label": "Supply steepness",
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      "group": "Shape",
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    }
  ],
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    "marker": true,
    "shape": "parallel",
    "ext": 2,
    "dSlope": 0.8,
    "sSlope": 0.8
  },
  "panels": [
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      "id": "main",
      "title": null,
      "xLabel": "Quantity",
      "yLabel": "Price",
      "xRange": [
        0,
        10
      ],
      "yRange": [
        0,
        10
      ],
      "axisKeys": {
        "x": "main:x",
        "y": "main:y"
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      "key": "main:y",
      "default": "Price",
      "hint": "Vertical axis",
      "panel": "main"
    },
    {
      "key": "main:x",
      "default": "Quantity",
      "hint": "Horizontal axis",
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    },
    {
      "key": "main.dwl",
      "default": "WL",
      "hint": "Shaded area",
      "panel": "main"
    },
    {
      "key": "main.external",
      "default": "external\ncost",
      "hint": "Arrow / line",
      "panel": "main"
    },
    {
      "key": "main.d",
      "default": "D = MPB",
      "hint": "Curve",
      "panel": "main"
    },
    {
      "key": "main.s",
      "default": "S = MPC = MSC",
      "hint": "Curve",
      "panel": "main"
    },
    {
      "key": "main.social",
      "default": "MSB",
      "hint": "Curve",
      "panel": "main"
    },
    {
      "key": "main.market:y",
      "default": "P_m",
      "hint": "Vertical-axis value",
      "panel": "main"
    },
    {
      "key": "main.market:x",
      "default": "Q_m",
      "hint": "Horizontal-axis value",
      "panel": "main"
    },
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      "key": "main.optimum:y",
      "default": "P*",
      "hint": "Vertical-axis value",
      "panel": "main"
    },
    {
      "key": "main.optimum:x",
      "default": "Q*",
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      "panel": "main"
    }
  ],
  "elements": [
    {
      "key": "main.dwl",
      "kind": "area",
      "label": "WL"
    },
    {
      "key": "main.external",
      "kind": "line",
      "label": "external\ncost"
    },
    {
      "key": "main.d",
      "kind": "curve",
      "label": "D = MPB"
    },
    {
      "key": "main.s",
      "kind": "curve",
      "label": "S = MPC = MSC"
    },
    {
      "key": "main.social",
      "kind": "curve",
      "label": "MSB"
    },
    {
      "key": "main.market",
      "kind": "point"
    },
    {
      "key": "main.optimum",
      "kind": "point"
    }
  ],
  "stats": null,
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    "params": {
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      "dwl": true,
      "marker": true,
      "shape": "parallel",
      "ext": 2,
      "dSlope": 0.8,
      "sSlope": 0.8
    }
  }
}