{
  "run": "023-delve-birthday",
  "as_of": "2026-07-15",
  "source": "arXiv abstracts via scholarweave/arxiv-latex (full arXiv mirror, queried in place with DuckDB); submission month = the yymm encoded in each arXiv id; tell-words per Kobak et al. 2024 (arXiv:2406.07016) excess vocabulary",
  "n_months": 197,
  "n_papers": 2479795,
  "n_abstract_words": 393583531,
  "window": [
    "1001",
    "2605"
  ],
  "chatgpt_launch": "2022-11-30",
  "focal_words": [
    "delve",
    "underscore",
    "showcase",
    "pivotal",
    "intricate",
    "meticulous",
    "garner",
    "boast",
    "tapestry",
    "commendable"
  ],
  "control_words": [
    "novel",
    "crucial",
    "notably",
    "remarkable"
  ],
  "delve": {
    "birthday": {
      "breakpoint": "2023-03",
      "breakpoint_ci95": [
        "2023-03",
        "2023-03"
      ],
      "months_after_launch": 3.5,
      "pre_slope_per_yr": 0.303,
      "slope_change_per_yr": 81.1,
      "r2_ascent": 0.972
    },
    "baseline_per_M": 2.34,
    "peak_month": "2312",
    "peak_per_M": 66.9,
    "fold_at_peak": 28.6,
    "fold_at_peak_vs_2010s": 88.0,
    "last3mo_per_M": 2.21,
    "down_from_peak_pct": 97.0,
    "now_below_baseline": true,
    "decay_halving_months": 5.2,
    "decay_r2": 0.94
  },
  "underscore_birthday": {
    "breakpoint": "2022-11",
    "breakpoint_ci95": [
      "2022-10",
      "2022-12"
    ],
    "months_after_launch": -0.5
  },
  "basket": {
    "baseline_per_M": 54.5,
    "peak_month": "2403",
    "peak_per_M": 529.2,
    "fold_at_peak": 9.7,
    "last3mo_per_M": 143.4,
    "down_from_peak_pct": 73.0
  },
  "novel": {
    "rate_2010": 203.0,
    "rate_2022": 816.0,
    "peak_month": "2503",
    "peak_per_M": 1232.0,
    "last3mo_per_M": 604.0,
    "down_from_peak_pct": 51.0
  },
  "words": {
    "delve": {
      "kind": "focal",
      "baseline_per_M": 2.34,
      "peak_month": "2312",
      "peak_per_M": 66.9,
      "fold_at_peak": 28.6,
      "last3mo_per_M": 2.21,
      "down_from_peak_pct": 97.0
    },
    "underscore": {
      "kind": "focal",
      "baseline_per_M": 3.42,
      "peak_month": "2505",
      "peak_per_M": 149.3,
      "fold_at_peak": 43.7,
      "last3mo_per_M": 53.54,
      "down_from_peak_pct": 64.0
    },
    "showcase": {
      "kind": "focal",
      "baseline_per_M": 21.72,
      "peak_month": "2403",
      "peak_per_M": 140.9,
      "fold_at_peak": 6.5,
      "last3mo_per_M": 28.34,
      "down_from_peak_pct": 80.0
    },
    "pivotal": {
      "kind": "focal",
      "baseline_per_M": 9.23,
      "peak_month": "2402",
      "peak_per_M": 91.9,
      "fold_at_peak": 10.0,
      "last3mo_per_M": 24.89,
      "down_from_peak_pct": 73.0
    },
    "intricate": {
      "kind": "focal",
      "baseline_per_M": 12.55,
      "peak_month": "2401",
      "peak_per_M": 95.3,
      "fold_at_peak": 7.6,
      "last3mo_per_M": 23.94,
      "down_from_peak_pct": 75.0
    },
    "meticulous": {
      "kind": "focal",
      "baseline_per_M": 1.37,
      "peak_month": "2403",
      "peak_per_M": 28.2,
      "fold_at_peak": 20.6,
      "last3mo_per_M": 4.32,
      "down_from_peak_pct": 85.0
    },
    "garner": {
      "kind": "focal",
      "baseline_per_M": 3.12,
      "peak_month": "2406",
      "peak_per_M": 28.5,
      "fold_at_peak": 9.2,
      "last3mo_per_M": 5.02,
      "down_from_peak_pct": 82.0
    },
    "boast": {
      "kind": "focal",
      "baseline_per_M": 0.5,
      "peak_month": "2311",
      "peak_per_M": 6.3,
      "fold_at_peak": 12.6,
      "last3mo_per_M": 0.61,
      "down_from_peak_pct": 90.0
    },
    "tapestry": {
      "kind": "focal",
      "baseline_per_M": 0.12,
      "peak_month": "2511",
      "peak_per_M": 2.2,
      "fold_at_peak": 18.9,
      "last3mo_per_M": 0.26,
      "down_from_peak_pct": 88.0
    },
    "commendable": {
      "kind": "focal",
      "baseline_per_M": 0.19,
      "peak_month": "2402",
      "peak_per_M": 4.2,
      "fold_at_peak": 22.7,
      "last3mo_per_M": 0.24,
      "down_from_peak_pct": 94.0
    },
    "novel": {
      "kind": "control",
      "baseline_per_M": 664.4,
      "peak_month": "2503",
      "peak_per_M": 1232.4,
      "fold_at_peak": 1.9,
      "last3mo_per_M": 603.94,
      "down_from_peak_pct": 51.0
    },
    "crucial": {
      "kind": "control",
      "baseline_per_M": 145.15,
      "peak_month": "2409",
      "peak_per_M": 414.3,
      "fold_at_peak": 2.9,
      "last3mo_per_M": 147.24,
      "down_from_peak_pct": 64.0
    },
    "notably": {
      "kind": "control",
      "baseline_per_M": 34.7,
      "peak_month": "2505",
      "peak_per_M": 164.6,
      "fold_at_peak": 4.7,
      "last3mo_per_M": 103.58,
      "down_from_peak_pct": 37.0
    },
    "remarkable": {
      "kind": "control",
      "baseline_per_M": 92.03,
      "peak_month": "2312",
      "peak_per_M": 185.6,
      "fold_at_peak": 2.0,
      "last3mo_per_M": 106.51,
      "down_from_peak_pct": 43.0
    }
  },
  "caveats": [
    "the stored abstract is the latest version's text; the most recent months are the least revised, so if machine polish arrives in later versions the right edge of the decline may deepen slightly less than drawn \u2014 but delve's fall began mid-2024, on data that has had two years to settle",
    "a word list detects a style, not authorship: assisted editing, non-native writers accepting suggestions, and humans imitating machine prose all count",
    "the pre-registered control words failed as controls \u2014 the style touched ordinary vocabulary too; reported as found",
    "the funeral does not mean less machine writing; it means machine writing that no longer announces itself \u2014 the curve measures detectability, not usage"
  ]
}