Can LLMs Predict Academic Collaboration? Topology Heuristics vs. LLM-Based Link Prediction on Real Co-authorship Networks
Organizations: Luddy School of Informatics, Computing, and Engineering Indiana University Bloomington · School of Data Science University of Virginia
Abstract
Can large language models (LLMs) predict which researchers will collaborate? We study this question through link prediction on real-world co-authorship networks from OpenAlex (9.96M authors, 108.7M edges), evaluating whether LLMs can predict future scientific collaborations using only author profiles, without access to graph structure. Using Qwen2.5-72B-Instruct across three historical eras of AI research, we find that LLMs and topology heuristics capture distinct signals and are strongest in complementary settings. On new-edge prediction under natural class imbalance, the LLM achieves AUROC 0.714--0.789, outperforming Common Neighbors, Jaccard, and Preferential Attachment, with recall up to 92.9%; under balanced evaluation, the LLM outperforms all topology heuristics in every era (AUROC 0.601--0.658 vs.\ best-heuristic 0.525--0.538); on continued edges, the LLM (0.687) is competitive with Adamic-Adar (0.684). Critically, 78.6--82.7% of new collaborations occur between authors with no common neighbor -- a blind spot where all topology heuristics score zero but the LLM still achieves AUROC 0.652 by reasoning from author metadata alone. A temporal metadata ablation reveals that research concepts are the dominant signal (removing concepts drops AUROC by 0.047--0.084). Providing pre-computed graph features to the LLM degrades performance due to anchoring effects, confirming that LLMs and topology methods should operate as separate, complementary channels. A socio-cultural ablation finds that name-inferred ethnicity and institutional country do not predict collaboration beyond topology, reflecting the demographic homogeneity of AI research. A node2vec baseline achieves AUROC comparable to Adamic-Adar, establishing that LLMs access a fundamentally different information channel -- author metadata -- rather than encoding the same structural signal differently.
Figures & tables
| Era | Name | Train | Eval | Authors | New Edges | 2-hop Cands. |
|---|---|---|---|---|---|---|
| 1 | Classical AI | 04–07 | 08–09 | 38,842 | 45,317 | 1.17M |
| 2 | DL Explosion | 10–15 | 16–17 | 393,843 | 914,270 | 61.6M |
| 3 | Democratization | 18–21 | 22–23 | 555,434 | 2,704,671 | 329.7M |
| Heuristic | Era 1 | Era 2 | Era 3 |
|---|---|---|---|
| Adamic-Adar | 0.750 | 0.826 | 0.823 |
| Resource Allocation | 0.735 | 0.813 | 0.803 |
| Common Neighbors | 0.656 | 0.699 | 0.726 |
| Jaccard Coefficient | 0.601 | 0.662 | 0.545 |
| Preferential Attach. | 0.491 | 0.437 | 0.574 |
| Era | Pos:Neg | LLM | AA | RA | CN | |
|---|---|---|---|---|---|---|
| Era 1 | 5,000 | 47:4,953 | 0.714 | 0.801 | 0.805 | 0.682 |
| Era 2 | 5,000 | 14:4,986 | 0.777 | 0.879 | 0.880 | 0.716 |
| Era 3 | 5,000 | 7:4,993 | 0.789 | 0.879 | 0.878 | 0.758 |
| Era | Pos:Neg | LLM | AA | RA | CN | |
|---|---|---|---|---|---|---|
| Era 1 | 500 | 250:250 | 0.658 | 0.533 | 0.531 | 0.538 |
| Era 2 | 500 | 250:250 | 0.615 | 0.520 | 0.524 | 0.525 |
| Era 3 | 500 | 250:250 | 0.601 | 0.509 | 0.512 | 0.533 |
| Era | w/ Conc. | No-Conc. | Era-Restr. | (conc.) | (era) |
|---|---|---|---|---|---|
| Era 1 | 0.573 | 0.526 | 0.544 | 0.047 | 0.018 |
| Era 2 | 0.694 | 0.610 | 0.562 | 0.084 | 0.048 |
| Era 3 | 0.707 | 0.627 | 0.570 | 0.080 | 0.057 |
| Category | Method | Era 1 | Era 2 |
|---|---|---|---|
| Topology | AA / CN / JC / RA | 0.500 | 0.500 |
| Pref. Attachment | 0.095 | 0.848 | |
| Embedding | N2V-Hadamard | 0.651 | 0.916 |
| N2V-Cosine | 0.154 | 0.848 | |
| Metadata | 0.876 | 0.942 | |
| 0.779 | 0.801 |
| Prompt Variant | AUROC | vs. Base |
|---|---|---|
| Base (metadata only) | 0.699 | — |
| + Country | 0.686 | |
| + Ethnicity | 0.686 | |
| + Both | 0.683 |
Appendix figures & tables22 assets
Supplementary material from the paper’s appendix.
Appendix
| Window | Authors | Edges | Avg Deg | Edge Gr. | E/A |
|---|---|---|---|---|---|
| 2004–05 | 631,767 | 2,257,606 | 7.15 | — | 3.6 |
| 2006–07 | 753,373 | 2,486,310 | 6.60 | 1.10 | 3.3 |
| 2008–09 | 875,530 | 3,322,828 | 7.59 | 1.34 | 3.8 |
| 2010–11 | 1,056,752 | 8,686,468 | 16.44 | 2.61 | 8.2 |
| 2012–13 | 1,220,422 | 12,628,718 | 20.70 | 1.45 | 10.3 |
| 2014–15 | 1,358,721 | 17,771,014 | 26.16 | 1.41 | 13.1 |
| Model | Prompt Variant | AUROC |
|---|---|---|
| Qwen-72B | v2 (metadata only) | 0.547 |
| Qwen-72B | v2 + network statistics | 0.486 |
| GPT-4o | v2 + network statistics | 0.467 |
| Field | Era-Restricted? | Method | Effort |
|---|---|---|---|
| display_name | Yes (stable) | No action needed | None |
| works_count | Yes (direct) | counts_by_year | 1 call/author |
| cited_by_count | Yes (direct) | counts_by_year | 1 call/author |
| institution | Yes (direct) | affiliations | 1 call/author |
| concepts/topics | No (indirect) | Per-work aggregation | Millions of calls |
| Method | Top-5 Concepts (2004–07) | Overlap |
|---|---|---|
| Career-level | CS, AI, ML, Math, Neural Networks | (reference) |
| Mean score | Pixel, Convexity, Variation, Isomap, SGD | 0/5 |
| Max score | RL, Isomap, Pixel, Dim. Reduction, Curse of Dim. | 0/5 |
| Frequency | CS, AI, Math, ML, Kernel | 4/5 |
| Citation-wtd | CS, AI, Training, ML, Layer | 3/5 |
| Top-5 voting | CS, AI, Math, Curse of Dim., ML | 4/5 |
| Era | Best N2V Op. | N2V AUROC | Best Topo | Topo AUROC | |
|---|---|---|---|---|---|
| Classical AI | L2 distance | 0.781 | AA | 0.773 | 0.008 |
| DL Explosion | Cosine | 0.834 | AA | 0.830 | 0.004 |
| Democratization | Cosine | 0.792 | RA | 0.854 | 0.062 |
| Method | AUROC |
|---|---|
| Resource Allocation | 0.706 |
| LLM (Qwen-72B) | 0.687 |
| Adamic-Adar | 0.684 |
| Edge Weight | 0.659 |
| Common Neighbors | 0.619 |
| Jaccard Coefficient | 0.618 |
| Category | Feature | AUROC |
| Topology | Adamic-Adar | 0.801 |
| Resource Allocation | 0.805 | |
| Metadata | Concept Overlap | 0.555 |
| Same Institution | 0.527 | |
| Socio-cultural | Same Ethnicity | 0.475 |
| Same Country | 0.448 |
| Feature | Collab. Same Rate | Non-collab. Same Rate | Homophily Ratio |
|---|---|---|---|
| Ethnicity | 83.0% | 88.0% | 0.94 |
| Country | 40.4% | 50.8% | 0.80 |
| Continent | 46.8% | 57.8% | 0.81 |
Link Prediction
Link prediction estimates missing or future relationships in graphs, from social ties and knowledge-graph facts to biological interactions.
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