AI makes software developers at least twice as efficient.
Mostly false False in substance, right in a detail.
Factual: Statements about the present or the past, checked against the record: did they hold up?
What would count as true or false
Judged against the evidence available by 2026-01-09 on how much AI tools raise software developers' productivity or efficiency. True: rigorous evidence (randomised trials, large field studies, systematic reviews) consistently shows gains of about 100% or more (twice the output or half the time) for developers generally. Mostly true: the evidence broadly shows gains close to 2x (about 80–100%) across typical development work. Mixed: some rigorous studies show 2x or more and others show much smaller gains, with no consensus. Mostly false: the evidence shows real but smaller gains (well below 2x, e.g. 10–60%), or shows 2x only for narrow tasks or settings, or the 2x figure is not established. False: the weight of rigorous evidence shows no productivity gain, or a slowdown, for developers generally.
Set before the research began.
Evidence (3)
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E1 Measuring the Impact of Early-2025 AI on Experienced Open-Source Developer Productivity METR · 10 July 2025
“When developers are allowed to use AI tools, they take 19% longer to complete issues—a significant slowdown that goes against developer beliefs and expert forecasts.”
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E2 The Effects of Generative AI on High-Skilled Work: Evidence from Three Field Experiments with Software Developers Kevin Zheyuan Cui, Mert Demirer, Sonia Jaffe, Leon Musolff, Sida Peng, and Tobias Salz (academic working paper) · June 2025
“Though each experiment is noisy, when data is combined across three experiments and 4,867 developers, our analysis reveals a 26.08% increase (SE: 10.3%) in completed tasks among developers using the AI tool.”
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E3 Research: quantifying GitHub Copilot's impact on developer productivity and happiness GitHub Blog · 7 September 2022
“These results are statistically significant (P=.0017) and the 95% confidence interval for the percentage speed gain is [21%, 89%].”
Reasoning
The best evidence here comes from large field experiments covering 4,867 developers. They found a 26.08% increase in completed tasks with AI tools, which is far below a doubling (E2). A controlled GitHub study put the 95% confidence interval for the speed gain at 21% to 89%, which also excludes 100% (E3). METR's study of experienced open-source developers found they took 19% longer to complete issues when allowed to use AI tools (E1). Taken together, the evidence shows a pooled 26.08% increase in completed tasks (E2), a GitHub speed-gain confidence interval of 21% to 89% that stops short of 100% (E3), and one slowdown (E1), so the claim that AI makes developers at least twice as efficient is not established.
Cite this claim
Bill Gates, “AI makes software developers at least twice as efficient.” (said 9 January 2026). Verdict: mostly false. Reliability API, claim c_8084d66fe548, method 0.1.0+c876030c, dataset release v1.1.2. https://epistacklabs.com/claims/c_8084d66fe548
This claim is in dataset release v1.1.2, with the same verdict.
Reply to this claim
More factual claims by Bill Gates
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Mostly true
“there is a robust debate going on in the computing industry about how to create it, and whether it can even be created at all”
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Mostly true
“Even lack of control that I thought would be many years from now, we’re seeing lack of control.”
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Mostly true
“Sometimes I do it if there’s three of us: Claude, ChatGPT and me, debating these things.”
Bill Gates sometimes debates topics in a three-way conversation with Claude and ChatGPT.
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Resolved true
“These are people who are super expert on the thing, going, well, maybe we won’t be able to control these things.”
Leading AI experts are saying humans may not be able to control these AI systems.
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Mixed
“There is no plan to ease the entry into the AI era.”
There is currently no plan to ease the entry into the AI era.
Verdicts are made automatically; how verdicts are made.