{
 "id": "p2026-09-06-138",
 "received": "2026-09-06T09:39:39-04:00",
 "proposer": "researcher (opus), brief 2026-09-06, era-2024-2026",
 "kind": "entry",
 "sha": "9851a1b5e8f9016d",
 "data": {
  "kind": "entry",
  "tech": "llm-coding-assistant",
  "tech_name": "LLM coding assistants (Claude 3.5/3.7 in Cursor Pro)",
  "definition": "a transformer language model fit to text and code, used inside an IDE agent",
  "from": "2025-02",
  "region": "world",
  "domain": "work",
  "side": "loss",
  "people": {
   "n": 16,
   "unit": "experienced open-source developers",
   "date": "2025-07-10"
  },
  "effect": {
   "n": 19,
   "unit": "percent",
   "date": "2025-07-10",
   "what": "took 19% longer to complete their own repositories' real issues when allowed AI tools, in a randomised controlled trial"
  },
  "reversible": true,
  "switch": "owner:AI coding-tool vendors",
  "statistic": "In a randomised trial run Feb–Jun 2025 on 246 real issues from their own large open-source repositories, 16 experienced developers took 19% longer with AI tools than without; they had forecast a 24% speed-up.",
  "source": "https://metr.org/blog/2025-07-10-early-2025-ai-experienced-os-dev-study/",
  "quote": "When developers are allowed to use AI tools, they take 19% longer to complete issues",
  "attribution": "named",
  "source_kind": "primary"
 },
 "from_file": "impacts/harvest/2026-09-06-era-2024-2026.md"
}