{
  "id": "keynesian-multiplier",
  "name": "Keynesian multiplier",
  "unit": "macro",
  "unitName": "Unit 3 · Macroeconomics",
  "topic": "Monetary & fiscal policy",
  "hl": true,
  "description": "An injection (e.g. ΔG) shifts AD by the initial amount, then successive rounds of induced spending shift it further: the final change in real GDP is k × ΔG, where k = 1/(1 − MPC).",
  "keywords": [
    "multiplier",
    "Keynesian multiplier",
    "MPC",
    "marginal propensity to consume",
    "injection",
    "induced spending",
    "k = 1/MPW"
  ],
  "schemaUrl": "https://graphs.lectere.com/api/v1/templates/keynesian-multiplier",
  "previewUrl": "https://graphs.lectere.com/thumbs/keynesian-multiplier.svg",
  "editorUrl": "https://graphs.lectere.com/graph/keynesian-multiplier/",
  "params": [
    {
      "key": "mpc",
      "label": "Marginal propensity to consume (MPC)",
      "default": 0.6,
      "type": "number",
      "min": 0.2,
      "max": 0.8,
      "step": 0.05
    },
    {
      "key": "inj",
      "label": "Initial injection, ΔG ($bn)",
      "default": 12,
      "type": "number",
      "min": 5,
      "max": 20,
      "step": 1
    },
    {
      "key": "measures",
      "label": "Label initial injection and multiplier effect",
      "default": true,
      "type": "boolean"
    }
  ],
  "defaults": {
    "mpc": 0.6,
    "inj": 12,
    "measures": true
  },
  "panels": [
    {
      "id": "main",
      "title": null,
      "xLabel": "Real GDP",
      "yLabel": "Average price level",
      "xRange": [
        0,
        10
      ],
      "yRange": [
        0,
        10
      ],
      "axisKeys": {
        "x": "main:x",
        "y": "main:y"
      }
    }
  ],
  "labels": [
    {
      "key": "main:y",
      "default": "Average price level",
      "hint": "Vertical axis",
      "panel": "main"
    },
    {
      "key": "main:x",
      "default": "Real GDP",
      "hint": "Horizontal axis",
      "panel": "main"
    },
    {
      "key": "main.as",
      "default": "AS",
      "hint": "Curve",
      "panel": "main"
    },
    {
      "key": "main.ad1",
      "default": "AD_1",
      "hint": "Curve",
      "panel": "main"
    },
    {
      "key": "main.ad2",
      "default": "AD_2",
      "hint": "Curve",
      "panel": "main"
    },
    {
      "key": "main.ad3",
      "default": "AD_3",
      "hint": "Curve",
      "panel": "main"
    },
    {
      "key": "main.e1:y",
      "default": "PL",
      "hint": "Vertical-axis value",
      "panel": "main"
    },
    {
      "key": "main.e1:x",
      "default": "Y_1",
      "hint": "Horizontal-axis value",
      "panel": "main"
    },
    {
      "key": "main.e2:x",
      "default": "Y_2",
      "hint": "Horizontal-axis value",
      "panel": "main"
    },
    {
      "key": "main.e3:x",
      "default": "Y_3",
      "hint": "Horizontal-axis value",
      "panel": "main"
    },
    {
      "key": "main.m1",
      "default": "ΔG",
      "hint": "Arrow / line",
      "panel": "main"
    },
    {
      "key": "main.m2",
      "default": "multiplier effect",
      "hint": "Arrow / line",
      "panel": "main"
    }
  ],
  "elements": [
    {
      "key": "main.as",
      "kind": "curve",
      "label": "AS"
    },
    {
      "key": "main.ad1",
      "kind": "curve",
      "label": "AD_1"
    },
    {
      "key": "main.ad2",
      "kind": "curve",
      "label": "AD_2"
    },
    {
      "key": "main.ad3",
      "kind": "curve",
      "label": "AD_3"
    },
    {
      "key": "main.e1",
      "kind": "point"
    },
    {
      "key": "main.e2",
      "kind": "point"
    },
    {
      "key": "main.e3",
      "kind": "point"
    },
    {
      "key": "main.m1",
      "kind": "line",
      "label": "ΔG"
    },
    {
      "key": "main.m2",
      "kind": "line",
      "label": "multiplier effect"
    }
  ],
  "stats": [
    {
      "label": "MPC",
      "value": "0.6"
    },
    {
      "label": "Multiplier, k = 1 / (1 − MPC)",
      "value": "2.5"
    },
    {
      "label": "Initial injection, ΔG",
      "value": "$12bn"
    },
    {
      "label": "Final change in AD (k × ΔG)",
      "value": "$30bn"
    }
  ],
  "example": {
    "template": "keynesian-multiplier",
    "params": {
      "mpc": 0.6,
      "inj": 12,
      "measures": true
    }
  }
}