A Closer Look at the Application of Causal Inference in Graph Representation Learning
Organizations: Institute of Software Chinese Academy of Science
Abstract
Modeling causal relationships in graph representation learning remains a fundamental challenge. Existing approaches often draw on theories and methods from causal inference to identify causal subgraphs or mitigate confounders. However, due to the inherent complexity of graph-structured data, these approaches frequently aggregate diverse graph elements into single causal variables, an operation that risks violating the core assumptions of causal inference. In this work, we prove that such aggregation compromises causal validity. Building on this conclusion, we propose a theoretical model grounded in the smallest indivisible units of graph data to ensure that the causal validity is guaranteed. With this model, we further analyze the costs of achieving precise causal modeling in graph representation learning and identify the conditions under which the problem can be simplified. To empirically support our theory, we construct a controllable synthetic dataset that reflects realworld causal structures and conduct extensive experiments for validation. Finally, we develop a causal modeling enhancement module that can be seamlessly integrated into existing graph learning pipelines, and we demonstrate its effectiveness through comprehensive comparative experiments.
Figures & tables
| Dataset | Adjustable | Known | Adjustable | Adjustable | Adjustable | Adjustable | Real-world |
| Elements ( ) | Causality | Motif | Node Feature | Edge Connection | Assemble Mode | Grounded Data | |
| Citeseer ( Giles et al., 1998 ) | Fixed | ✓ | |||||
| PROTEINS ( Morris et al., 2020 ) | Fixed | ✓ | |||||
| Synthetic Graph ( Ying et al., 2019 ) | 5 | ✓ | ✓ | ||||
| Spurious-Motif ( Wu et al., 2022b ) | 6 | ✓ | ✓ | ||||
| CRCG ( Gao et al., 2024 ) | 54 | ✓ | ✓ | ✓ | ✓ |
| Method | RWG-Molecular | Spmotif-M | Spmotif-C | RWG–Citation | CRCG | CiteSeer | ENZYMES |
| CaNet | 52.17 ± 2.02 | 32.40 ± 1.30 | 45.00 ± 1.32 | 59.33 ± 1.04 | 32.77 ± 1.27 | 83.87 ± 0.67 | 17.00 ± 6.78 |
| CaNet+REC | 56.50 ± 2.65 | 34.17 ± 1.35 | 46.83 ± 3.06 | 61.83 ± 0.76 | 36.43 ± 1.17 | 84.90 ± 0.12 | 18.33 ± 6.94 |
| Improvement | +4.33 | +1.77 | +1.83 | +2.50 | +3.66 | +1.03 | +1.33 |
| CRCG | 45.50 ± 3.53 | 36.80 ± 1.89 | 44.50 ± 2.91 | 45.50 ± 6.29 | 29.70 ± 4.62 | 42.78 ± 3.76 | 34.67 ± 7.10 |
| CRCG+REC | 45.50 ± 4.39 | 38.17 ± 3.83 | 50.50 ± 3.05 | 47.50 ± 6.26 | 33.10 ± 5.29 | 44.07 ± 3.30 | 40.33 ± 3.24 |
| Improvement | +0.00 | +1.37 | +6.00 | +2.00 | +3.40 | +1.29 | +5.66 |
Appendix figures & tables11 assets
Supplementary material from the paper’s appendix.
Appendix
| Molecule | Molecular Formula | Node Count | Edge Count |
| Acetic Acid | C 2 H 4 O 2 | 3 | 2 |
| Adrenaline | C 9 H 13 NO 3 | 5 | 6 |
| Ammonia | NH 3 | 2 | 3 |
| Anthracene | C 14 H 10 | 24 | 12 |
| Benzene Ring | C 6 H 6 | 6 | 6 |
| Benzoic Acid | C 7 H 6 O 2 | 9 | 8 |
| Motif Name | Construction Method | Functionality Description |
| Star Motif | Central node connected to all others | Generates a star structure with one center node connected to all peripheral nodes. |
| Path Motif | Nodes connected in sequence | Constructs a linear path where each node connects to the next in sequence. |
| Fan Motif | Central node with multiple branch nodes | Creates a fan-like shape with a central hub and several outward branches, possibly interconnected. |
| Cusped Polygon Motif | Polygon with potential branches | Builds a polygon structure with pointed (cusped) corners and optional branching substructures. |
| Random Bipartite Motif | Bipartite graph with random connections | Generates a bipartite graph where two partitions are randomly interconnected. |
| Tree Motif | Hierarchical branching structure | Constructs a tree graph where each node may connect to multiple child nodes. |
| Link Rule | Description |
| Random Citation Generation | Each paper randomly cites a set of papers; the number of citations follows a Poisson distribution. |
| Citation by High Citation Count | Each paper cites papers with higher citation counts to increase connectivity among highly cited papers. |
| Co-Author Based Citation | Papers by authors who have collaborated with the current paper’s authors are preferentially cited. |
| Propagation-Based Citation | Citation links are simulated using an information diffusion model (e.g., Independent Cascade). |
| Topic Similarity-Based Citation | Papers with high topic similarity (e.g., via cosine similarity on keywords/abstracts) are cited. |
| Temporal Citation | Older papers are preferentially cited to simulate time-evolving citation behavior. |
| Type | Description |
| Normal Distribution | Generates node features based on a normal distribution with specified mean and standard deviation. |
| Uniform Distribution | Generates node features based on a uniform distribution over a specified range. |
| Exponential Distribution | Generates node features based on an exponential distribution. |
| Lognormal Distribution | Generates node features based on a lognormal distribution. |
| Gamma Distribution | Generates node features based on a gamma distribution. |
| Beta Distribution | Generates node features based on a beta distribution. |