Anthropic's Economic Research Center published a paper titled *Agentic Coding and Persistent Returns to Expertise* on June 16, 2026. Based on real-world data from roughly 400,000 Claude Code sessions by 235,000 users over seven months (October 2025 – April 2026), it addresses a core question: when AI can write code, does human expertise still matter?
The surprising answer: expertise has not depreciated—it is more important than expected.
Source: https://www.anthropic.com/research/claude-code-expertise
Methodology
Anthropic used its Clio privacy-analysis framework for de-identification, then had Claude Sonnet 4.6 read each session transcript, cross-validated with telemetry data. A decision-attribution classifier identified every "meaningful decision," splitting them into planning decisions (what to do) and execution decisions (how to do it), attributing each to either the user or Claude.
Key Data
| Dimension | Value | |---|---| | Total sessions | ~400,000 | | Users | ~235,000 | | Time window | Oct 2025 – Apr 2026 | | Typical turns per session | ~4 | | Avg. Claude operations per session | ~10 | | Avg. output length | ~2,400 words |
Human–AI Division of Labor
- Users make on average 70% of planning decisions (what to build, which approach, what "done" means)
- Claude makes on average 80% of execution decisions (which files to change, what code to write, which commands to run)
- Novice sessions: only 4% verified success after being blocked
- Expert sessions: 15% verified success after being blocked
- Fixing code fell from 33% to 19% of sessions—use is shifting toward end-to-end tasks
- Operating software rose from 14% to 21%
- Data analysis and document writing roughly doubled from ~10% to 20%
- For developers: AI won't take your job, but it will widen the gap between peers. The deeper your expertise, the greater the leverage AI provides. Those who ask good questions will be worth more than those who write code.
- For enterprises: Training employees to "use AI to code" is the entry-level move; the scarce, valuable skill is "posing problems AI can understand," which requires business understanding.
- For AI product design: Copilot-style autocomplete has peaked. Next-generation products hinge on genuinely understanding users' domain intent.
- For labor markets: Software engineers' moat lies not in writing code but in judging which code is worth writing. Coding agents are replacing implementation work while rewarding deep understanding of the problem being solved.
This boundary is stable: humans own "understanding the problem," AI owns "using the tools."
Returns to Expertise
| User level | Verified success | At least partial success | |---|---|---| | Novice | 15% | 77% | | Intermediate | 28% | 91% | | Advanced/Expert | 33% | 92% |
The key difference lies in recovery from setbacks:
Novices abandon 19% of failed sessions; experts only 5–7%. Experts don't just perform better—they know how to work around errors.
Notably, expertise is task-specific: a senior engineer asking their first Rust question is still a novice in that task; an accountant who doesn't know Python but can precisely describe reconciliation rules and spot edge cases is an expert in that task.
Convergence Across Occupations
Task success rates across occupations are within 7 percentage points of software engineers; management roles are slightly higher (possibly due to more precise expression). Software development is becoming a universal professional skill rather than a programmer-exclusive one.
Trends Over Seven Months
Claude Code's role is shifting from "code editor" to "workflow executor."
Why It Matters
Caveats and Open Questions
1. Sample bias: Claude Code users skew technical and senior; conclusions may not extend to non-technical users. 2. Task value unmeasured: The study cannot tell whether generated code was actually used or created economic value. 3. Non-interactive usage excluded: A significant share of API and automation use cases were not covered, where returns to expertise may differ. 4. Durability uncertain: The authors explicitly flag whether returns to expertise decline—and whether non-engineer success rates keep rising—as ongoing monitoring signals, acknowledging the conclusions could reverse.
One-line takeaway: In the AI coding era, domain expertise hasn't been devalued—it has become the most valuable lever. Those who can ask good questions are scarcer than those who can write code.