A Cross-Disciplinary Bibliometric Analysis using Difference-in-Differences Estimation across 8 Disciplines (2018-2025)
Quantifying how LLMs have systematically altered scientific production across disciplines since the release of ChatGPT in late 2022.
What is the macro-level impact of Large Language Models on the scientific enterprise? This work develops a comprehensive cross-disciplinary framework using synthetic bibliometric time-series data calibrated to observed publication trends from 2018 to 2025. The framework measures publication volume, citation impact, research novelty, interdisciplinary collaboration, LLM vocabulary signals, retraction rates, review turnaround times, and collaboration breadth across 8 disciplines spanning STEM, social sciences, medicine, and the humanities.
Difference-in-Differences (DiD): Disciplines are partitioned into treatment (high LLM adoption: Computer Science at 0.85, Medicine at 0.55, Physics at 0.52) and control groups (low adoption: Mathematics at 0.35, Psychology at 0.38, Humanities at 0.22). The DiD estimator isolates causal LLM effects beyond organic growth trends.
Composite Impact Index: Aggregates normalized changes across 7 metrics with weights: publication volume (0.20), citations (0.15), novelty (0.15), interdisciplinary fraction (0.15), retraction rate (0.10), review turnaround (0.10), collaboration breadth (0.15).
Explore the bibliometric trends across disciplines. Use the tabs to switch between different visualizations.
Scatter plots showing how LLM adoption level correlates with key outcomes across disciplines.
Detailed numerical results from the analysis.
| Metric | DiD Estimate | Std Error | t-statistic | p-value | Significant |
|---|---|---|---|---|---|
| Publications (K) | 102.34 | 39.87 | 2.567 | 0.014 | Yes |
| Mean Citations | 0.052 | 0.169 | 0.311 | 0.758 | No |
| Novelty Index | -0.023 | 0.008 | -2.809 | 0.007 | Yes |
| Interdisc. Fraction | 0.007 | 0.008 | 0.787 | 0.435 | No |
| LLM Vocab Signal | 0.031 | 0.007 | 4.586 | <0.001 | Yes |
| Retraction Rate | -0.001 | 0.172 | -0.007 | 0.995 | No |
| Review Turnaround | -0.762 | 1.622 | -0.470 | 0.641 | No |
| Collab. Breadth | 0.086 | 0.098 | 0.879 | 0.384 | No |
| Discipline | Adoption | Pub. Change % | Novelty Change % | Vocab Signal % | Interdisc. % | Collab. % | Composite |
|---|---|---|---|---|---|---|---|
| Computer Science | 0.85 | +86.40 | -18.92 | 816.29 | +30.66 | +17.67 | 20.09 |
| Medicine | 0.55 | +47.60 | -16.28 | 635.69 | +25.81 | +18.61 | 11.93 |
| Biology | 0.48 | +36.48 | -13.58 | 343.13 | +23.91 | +17.84 | 9.87 |
| Psychology | 0.38 | +29.48 | -8.49 | 282.39 | +27.57 | +16.31 | 9.56 |
| Physics | 0.52 | +29.35 | -12.90 | 564.09 | +28.44 | +15.97 | 8.78 |
| Economics | 0.42 | +28.44 | -10.55 | 480.39 | +23.22 | +15.83 | 7.98 |
| Mathematics | 0.35 | +22.25 | -12.46 | 371.70 | +25.70 | +14.21 | 5.95 |
| Humanities | 0.22 | +8.41 | -7.39 | 143.53 | +19.81 | +13.82 | 3.81 |
| Metric | Spearman rho | p-value | Significant |
|---|---|---|---|
| Publications | 0.881 | 0.004 | Yes |
| Mean Citations | 0.048 | 0.911 | No |
| Novelty Index | -0.905 | 0.002 | Yes |
| Interdisc. Fraction | 0.691 | 0.058 | No |
| Retraction Rate | 0.048 | 0.911 | No |
| Discipline | Pre-LLM Mean | Post-LLM Mean | Fold Change | t-statistic | p-value | Significant |
|---|---|---|---|---|---|---|
| Computer Science | 0.0089 | 0.0817 | 9.16 | 8.965 | 0.011 | Yes |
| Medicine | 0.0085 | 0.0625 | 7.36 | 3.965 | 0.056 | No |
| Physics | 0.0091 | 0.0602 | 6.64 | 7.829 | 0.014 | Yes |
| Economics | 0.0085 | 0.0493 | 5.80 | 6.271 | 0.014 | Yes |
| Mathematics | 0.0097 | 0.0456 | 4.72 | 15.054 | <0.001 | Yes |
| Biology | 0.0118 | 0.0525 | 4.43 | 5.926 | 0.027 | Yes |
| Psychology | 0.0106 | 0.0405 | 3.82 | 4.643 | 0.041 | Yes |
| Humanities | 0.0126 | 0.0307 | 2.44 | 4.109 | 0.044 | Yes |
| Aggregate | 0.0100 | 0.0529 | 5.29 | 11.411 | <0.001 | Yes |
| Cluster | Disciplines | Mean Adoption | Mean Composite | Std Composite | Mean Pub. Change % | Mean Novelty Change % |
|---|---|---|---|---|---|---|
| STEM | CS, Physics, Biology, Math | 0.55 | 11.17 | 6.17 | +43.62 | -14.46 |
| Medical | Medicine | 0.55 | 11.93 | 0.00 | +47.60 | -16.28 |
| Social Sciences | Economics, Psychology | 0.40 | 8.77 | 1.12 | +28.96 | -9.52 |
| Humanities | Humanities | 0.22 | 3.81 | 0.00 | +8.41 | -7.39 |