{
  "schema": "ev-threshold-exercise-data/v1",
  "revision": "r6",
  "sourceEdition": "2026-09-18",
  "sourceArchiveSha256": "e5e67eb8a7bfa34620f6b6e0f608537a449a18a4acff5e3745a1d865acee674a",
  "chartId": "multi-series-line-chart",
  "contract": {
    "schema": "ev-threshold-exercise/v1",
    "title": "Draw the next five years.",
    "kicker": "The threshold test / a D3 exercise",
    "question": "Does crossing a five-percent BEV sales share tell you what comes next?",
    "countries": [
      "Germany",
      "Norway",
      "Netherlands",
      "Sweden",
      "United Kingdom",
      "France"
    ],
    "thresholdPercent": 5,
    "horizonYears": 5,
    "stepPercent": 0.5,
    "starterAnnualGain": 4,
    "instruction": "Start at the first supplied annual observation at or above 5%. Shape the next five points, then open the historical record. The starting share is the actual observation, not an invented exact crossing.",
    "starter": "The editable starter adds four percentage points per year, rounded to half-point steps. It is a drawing aid, not an estimate or a forecast.",
    "finding": "Each of these six selected histories reverses at least once over the following five years. A milestone is not a promise of uninterrupted growth.",
    "scope": "Six selected European teaching cases with five complete annual follow-up observations. They are not representative of all countries or of every threshold crosser. Calendar windows differ by market.",
    "boundary": "This is a retrospective intuition exercise using revised, rounded IEA/OWID observations, not a blind forecast experiment or a test of forecasting skill. The reader sketch is not an empirical estimate. Crossing 5% does not identify a causal tipping point.",
    "unit": "BEV share of new sales (%), IEA Cars. This scope differs from KBA passenger-car registrations.",
    "scoring": "Mean absolute error is the average absolute gap across the five follow-up years, in percentage points. The flat benchmark holds the initial observed share. The anchor year is excluded from both scores.",
    "source": {
      "label": "IEA Global EV Outlook 2026 / OWID compilation",
      "href": "https://ourworldindata.org/electric-car-sales",
      "csv": "/data/ev-diffusion/tables/global_country_year.csv",
      "edition": "2026-09-18"
    }
  },
  "trials": [
    {
      "country": "Germany",
      "anchorYear": 2020,
      "points": [
        {
          "year": 2020,
          "share": 6.820513,
          "offset": 0
        },
        {
          "year": 2021,
          "share": 13.56522,
          "offset": 1
        },
        {
          "year": 2022,
          "share": 17.55422,
          "offset": 2
        },
        {
          "year": 2023,
          "share": 17.82857,
          "offset": 3
        },
        {
          "year": 2024,
          "share": 13.33333,
          "offset": 4
        },
        {
          "year": 2025,
          "share": 19.18605,
          "offset": 5
        }
      ]
    },
    {
      "country": "Norway",
      "anchorYear": 2013,
      "points": [
        {
          "year": 2013,
          "share": 5.56068,
          "offset": 0
        },
        {
          "year": 2014,
          "share": 13.82488,
          "offset": 1
        },
        {
          "year": 2015,
          "share": 16.87316,
          "offset": 2
        },
        {
          "year": 2016,
          "share": 15.46667,
          "offset": 3
        },
        {
          "year": 2017,
          "share": 20.75806,
          "offset": 4
        },
        {
          "year": 2018,
          "share": 30.87671,
          "offset": 5
        }
      ]
    },
    {
      "country": "Netherlands",
      "anchorYear": 2018,
      "points": [
        {
          "year": 2018,
          "share": 5.391304,
          "offset": 0
        },
        {
          "year": 2019,
          "share": 13.7594,
          "offset": 1
        },
        {
          "year": 2020,
          "share": 20.68966,
          "offset": 2
        },
        {
          "year": 2021,
          "share": 19.43617,
          "offset": 3
        },
        {
          "year": 2022,
          "share": 23.8785,
          "offset": 4
        },
        {
          "year": 2023,
          "share": 31.02564,
          "offset": 5
        }
      ]
    },
    {
      "country": "Sweden",
      "anchorYear": 2020,
      "points": [
        {
          "year": 2020,
          "share": 9.531915,
          "offset": 0
        },
        {
          "year": 2021,
          "share": 18.15556,
          "offset": 1
        },
        {
          "year": 2022,
          "share": 31.80368,
          "offset": 2
        },
        {
          "year": 2023,
          "share": 38.59649,
          "offset": 3
        },
        {
          "year": 2024,
          "share": 34.72611,
          "offset": 4
        },
        {
          "year": 2025,
          "share": 35.26012,
          "offset": 5
        }
      ]
    },
    {
      "country": "United Kingdom",
      "anchorYear": 2020,
      "points": [
        {
          "year": 2020,
          "share": 6.797753,
          "offset": 0
        },
        {
          "year": 2021,
          "share": 11.03226,
          "offset": 1
        },
        {
          "year": 2022,
          "share": 16.05405,
          "offset": 2
        },
        {
          "year": 2023,
          "share": 15.84444,
          "offset": 3
        },
        {
          "year": 2024,
          "share": 18.65455,
          "offset": 4
        },
        {
          "year": 2025,
          "share": 23.5,
          "offset": 5
        }
      ]
    },
    {
      "country": "France",
      "anchorYear": 2020,
      "points": [
        {
          "year": 2020,
          "share": 6.540541,
          "offset": 0
        },
        {
          "year": 2021,
          "share": 9.322581,
          "offset": 1
        },
        {
          "year": 2022,
          "share": 12.35294,
          "offset": 2
        },
        {
          "year": 2023,
          "share": 16.48936,
          "offset": 3
        },
        {
          "year": 2024,
          "share": 16,
          "offset": 4
        },
        {
          "year": 2025,
          "share": 19.64444,
          "offset": 5
        }
      ]
    }
  ],
  "starterComparisons": [
    {
      "country": "Germany",
      "status": "illustrative starting sketch, not an estimate or a forecast",
      "sketch": [
        11,
        15,
        19,
        23,
        27
      ],
      "rows": [
        {
          "year": 2021,
          "share": 13.56522,
          "offset": 1,
          "guess": 11,
          "flat": 6.820513,
          "error": -2.56522,
          "absoluteError": 2.56522
        },
        {
          "year": 2022,
          "share": 17.55422,
          "offset": 2,
          "guess": 15,
          "flat": 6.820513,
          "error": -2.554220000000001,
          "absoluteError": 2.554220000000001
        },
        {
          "year": 2023,
          "share": 17.82857,
          "offset": 3,
          "guess": 19,
          "flat": 6.820513,
          "error": 1.1714300000000009,
          "absoluteError": 1.1714300000000009
        },
        {
          "year": 2024,
          "share": 13.33333,
          "offset": 4,
          "guess": 23,
          "flat": 6.820513,
          "error": 9.66667,
          "absoluteError": 9.66667
        },
        {
          "year": 2025,
          "share": 19.18605,
          "offset": 5,
          "guess": 27,
          "flat": 6.820513,
          "error": 7.813949999999998,
          "absoluteError": 7.813949999999998
        }
      ],
      "mae": 4.754298,
      "flatMae": 9.472965
    },
    {
      "country": "Norway",
      "status": "illustrative starting sketch, not an estimate or a forecast",
      "sketch": [
        9.5,
        13.5,
        17.5,
        21.5,
        25.5
      ],
      "rows": [
        {
          "year": 2014,
          "share": 13.82488,
          "offset": 1,
          "guess": 9.5,
          "flat": 5.56068,
          "error": -4.32488,
          "absoluteError": 4.32488
        },
        {
          "year": 2015,
          "share": 16.87316,
          "offset": 2,
          "guess": 13.5,
          "flat": 5.56068,
          "error": -3.3731599999999986,
          "absoluteError": 3.3731599999999986
        },
        {
          "year": 2016,
          "share": 15.46667,
          "offset": 3,
          "guess": 17.5,
          "flat": 5.56068,
          "error": 2.0333299999999994,
          "absoluteError": 2.0333299999999994
        },
        {
          "year": 2017,
          "share": 20.75806,
          "offset": 4,
          "guess": 21.5,
          "flat": 5.56068,
          "error": 0.7419399999999996,
          "absoluteError": 0.7419399999999996
        },
        {
          "year": 2018,
          "share": 30.87671,
          "offset": 5,
          "guess": 25.5,
          "flat": 5.56068,
          "error": -5.376709999999999,
          "absoluteError": 5.376709999999999
        }
      ],
      "mae": 3.1700039999999996,
      "flatMae": 13.999216
    },
    {
      "country": "Netherlands",
      "status": "illustrative starting sketch, not an estimate or a forecast",
      "sketch": [
        9.5,
        13.5,
        17.5,
        21.5,
        25.5
      ],
      "rows": [
        {
          "year": 2019,
          "share": 13.7594,
          "offset": 1,
          "guess": 9.5,
          "flat": 5.391304,
          "error": -4.259399999999999,
          "absoluteError": 4.259399999999999
        },
        {
          "year": 2020,
          "share": 20.68966,
          "offset": 2,
          "guess": 13.5,
          "flat": 5.391304,
          "error": -7.18966,
          "absoluteError": 7.18966
        },
        {
          "year": 2021,
          "share": 19.43617,
          "offset": 3,
          "guess": 17.5,
          "flat": 5.391304,
          "error": -1.9361700000000006,
          "absoluteError": 1.9361700000000006
        },
        {
          "year": 2022,
          "share": 23.8785,
          "offset": 4,
          "guess": 21.5,
          "flat": 5.391304,
          "error": -2.378499999999999,
          "absoluteError": 2.378499999999999
        },
        {
          "year": 2023,
          "share": 31.02564,
          "offset": 5,
          "guess": 25.5,
          "flat": 5.391304,
          "error": -5.525639999999999,
          "absoluteError": 5.525639999999999
        }
      ],
      "mae": 4.257873999999999,
      "flatMae": 16.36657
    },
    {
      "country": "Sweden",
      "status": "illustrative starting sketch, not an estimate or a forecast",
      "sketch": [
        13.5,
        17.5,
        21.5,
        25.5,
        29.5
      ],
      "rows": [
        {
          "year": 2021,
          "share": 18.15556,
          "offset": 1,
          "guess": 13.5,
          "flat": 9.531915,
          "error": -4.655560000000001,
          "absoluteError": 4.655560000000001
        },
        {
          "year": 2022,
          "share": 31.80368,
          "offset": 2,
          "guess": 17.5,
          "flat": 9.531915,
          "error": -14.30368,
          "absoluteError": 14.30368
        },
        {
          "year": 2023,
          "share": 38.59649,
          "offset": 3,
          "guess": 21.5,
          "flat": 9.531915,
          "error": -17.096490000000003,
          "absoluteError": 17.096490000000003
        },
        {
          "year": 2024,
          "share": 34.72611,
          "offset": 4,
          "guess": 25.5,
          "flat": 9.531915,
          "error": -9.226109999999998,
          "absoluteError": 9.226109999999998
        },
        {
          "year": 2025,
          "share": 35.26012,
          "offset": 5,
          "guess": 29.5,
          "flat": 9.531915,
          "error": -5.760120000000001,
          "absoluteError": 5.760120000000001
        }
      ],
      "mae": 10.208392,
      "flatMae": 22.176477000000002
    },
    {
      "country": "United Kingdom",
      "status": "illustrative starting sketch, not an estimate or a forecast",
      "sketch": [
        11,
        15,
        19,
        23,
        27
      ],
      "rows": [
        {
          "year": 2021,
          "share": 11.03226,
          "offset": 1,
          "guess": 11,
          "flat": 6.797753,
          "error": -0.032260000000000844,
          "absoluteError": 0.032260000000000844
        },
        {
          "year": 2022,
          "share": 16.05405,
          "offset": 2,
          "guess": 15,
          "flat": 6.797753,
          "error": -1.0540500000000002,
          "absoluteError": 1.0540500000000002
        },
        {
          "year": 2023,
          "share": 15.84444,
          "offset": 3,
          "guess": 19,
          "flat": 6.797753,
          "error": 3.1555599999999995,
          "absoluteError": 3.1555599999999995
        },
        {
          "year": 2024,
          "share": 18.65455,
          "offset": 4,
          "guess": 23,
          "flat": 6.797753,
          "error": 4.34545,
          "absoluteError": 4.34545
        },
        {
          "year": 2025,
          "share": 23.5,
          "offset": 5,
          "guess": 27,
          "flat": 6.797753,
          "error": 3.5,
          "absoluteError": 3.5
        }
      ],
      "mae": 2.417464,
      "flatMae": 10.219307
    },
    {
      "country": "France",
      "status": "illustrative starting sketch, not an estimate or a forecast",
      "sketch": [
        10.5,
        14.5,
        18.5,
        22.5,
        26.5
      ],
      "rows": [
        {
          "year": 2021,
          "share": 9.322581,
          "offset": 1,
          "guess": 10.5,
          "flat": 6.540541,
          "error": 1.1774190000000004,
          "absoluteError": 1.1774190000000004
        },
        {
          "year": 2022,
          "share": 12.35294,
          "offset": 2,
          "guess": 14.5,
          "flat": 6.540541,
          "error": 2.1470599999999997,
          "absoluteError": 2.1470599999999997
        },
        {
          "year": 2023,
          "share": 16.48936,
          "offset": 3,
          "guess": 18.5,
          "flat": 6.540541,
          "error": 2.0106399999999987,
          "absoluteError": 2.0106399999999987
        },
        {
          "year": 2024,
          "share": 16,
          "offset": 4,
          "guess": 22.5,
          "flat": 6.540541,
          "error": 6.5,
          "absoluteError": 6.5
        },
        {
          "year": 2025,
          "share": 19.64444,
          "offset": 5,
          "guess": 26.5,
          "flat": 6.540541,
          "error": 6.8555600000000005,
          "absoluteError": 6.8555600000000005
        }
      ],
      "mae": 3.7381358,
      "flatMae": 8.2213232
    }
  ],
  "defaultReceipt": [
    "THE THRESHOLD TEST / RETROSPECTIVE READER EXERCISE",
    "Market: Germany. First supplied annual reading at or above 5%: 2020, 6.820513%.",
    "Sketch: Unedited starting template, not a reader forecast. Record not yet opened.",
    "2021: sketch 11.0%; observation not revealed in this exercise.",
    "2022: sketch 15.0%; observation not revealed in this exercise.",
    "2023: sketch 19.0%; observation not revealed in this exercise.",
    "2024: sketch 23.0%; observation not revealed in this exercise.",
    "2025: sketch 27.0%; observation not revealed in this exercise.",
    "BEV share of new sales (%), IEA Cars. This scope differs from KBA passenger-car registrations.",
    "Mean absolute error is the average absolute gap across the five follow-up years, in percentage points. The flat benchmark holds the initial observed share. The anchor year is excluded from both scores.",
    "This is a retrospective intuition exercise using revised, rounded IEA/OWID observations, not a blind forecast experiment or a test of forecasting skill. The reader sketch is not an empirical estimate. Crossing 5% does not identify a causal tipping point.",
    "https://ourworldindata.org/electric-car-sales",
    ""
  ]
}