productivityatlas.

Research / Chapter 04

Does AI actually save time?

What studies measure, where they disagree, and how to run a pilot.

Research edition · 14 September 2026

The report’s observations, prices and forecasts are a dated snapshot. Examples of savings are estimates unless explicitly identified as study results. This is not a fresh verification of every claim.

Evidence table

Study Design and population Finding What it does not prove
Brynjolfsson, Li, Raymond, QJE / NBER Staggered field rollout to 5,179 customer-support agents About 14% more issues resolved per hour on average; roughly 34% improvement for novice and low-skilled workers; little effect for experienced/high-skilled workers General knowledge work, long-term labor effects, or every chatbot product
Dell’Acqua et al., HBS/BCG, Organization Science Preregistered experiment with 758 consultants and 18 realistic tasks Inside the AI frontier: 12.2% more tasks, 25.1% faster, and higher quality; outside the frontier, AI could hurt performance Safe delegation of arbitrary professional judgment
Dillon et al., Microsoft Research Six-month randomized field experiment with about 6,000 knowledge workers using AI in email, documents, and meetings Users spent around three fewer hours per week on email; documents appeared moderately faster; meeting time did not significantly change Organization-wide productivity or whether saved time became leisure rather than more output
Cui et al., Management Science Three company-run randomized field experiments at Microsoft, Accenture, and a Fortune 100 firm; 4,867 developers Combined 26.08% increase in completed tasks; effects varied and less experienced developers adopted more Every codebase, seniority group, or quality/security outcome
Becker et al., METR Randomized trial with 16 experienced open-source developers and 246 tasks using early-2025 tools Developers estimated a 20% speedup, but measured completion time increased 19% in this setting Current models, novice developers, or simpler greenfield tasks

Interpretation

The strongest evidence clusters around tasks with clear inputs, repeated patterns, fast feedback, and a measurable output: customer-support responses, code completion, email drafting, document transformation, structured research, and meeting capture. Gains are less certain when the task requires deep domain context, ambiguous goals, novel judgment, or long-horizon coordination.

Time saved can be redistributed into more output, higher quality, learning, or more meetings. The website should therefore report at least four separate metrics:

  • Cycle time: time from request to acceptable completion.
  • Throughput: number of acceptable outcomes per person or team.
  • Quality: rubric score, error rate, rework, or customer outcome.
  • Human cost: review time, context switching, cognitive load, and escalation burden.

An AI tool that cuts drafting time by 30% but adds 20 minutes of checking, or produces 10% more output that no one wants, has not delivered the claimed 30% productivity gain.

Pilot measurement protocol

  1. Define the baseline task, input quality, cycle time, acceptable-quality rubric, and error cost.
  2. Run a control period without the AI feature and a treatment period with it.
  3. Record user time, AI time, review time, rework, escalations, and exceptions.
  4. Segment by user experience, task type, language, and data complexity.
  5. Review a random sample for factuality, completeness, tone, security, and policy compliance.
  6. Measure whether the “saved” time changed output, focus, learning, service level, or workload.
  7. Stop or redesign the pilot if errors or review costs erase the benefit.