Small and Medium Enterprises (SMEs) constitute 99.9% of U.S. businesses and generate 44% of economic activity, yet systematically identifying high-potential SMEs remains an open challenge. We introduce SME-HGT, a Heterogeneous Graph Transformer framework that predicts which SBIR Phase I awardees will advance to Phase II funding using exclusively public data. We construct a heterogeneous graph with 32,268 company nodes, 124 research topic nodes, and 13 government agency nodes connected by approximately 99,000 edges across three semantic relation types. SME-HGT achieves an AUPRC of 0.621 0.003 on a temporally-split test set, outperforming an MLP baseline (0.590 0.002) and R-GCN (0.608 0.013) across five random seeds. At a screening depth of 100 companies, SME-HGT attains 89.6% precision with a 2.14 lift over random selection. Our temporal evaluation protocol prevents information leakage, and our reliance on public data ensures reproducibility. These results demonstrate that relational structure among firms, research topics, and funding agencies provides meaningful signal for SME potential assessment, with implications for policymakers and early-stage investors.
Figure 1. SME-HGT architecture. Input features are projected per node type to a shared dimension, then refined through three HGT layers with residual connections. Only company node embeddings are passed to the classifier. A vertical flowchart showing five blocks connected by arrows from bottom to top: Heterogeneous Graph input, Type-Specific Linear Projection, three repeated HGT Layers with Residual connections and LayerNorm and Dropout, MLP Classifier for Company nodes, and Phase II Prediction output.
Model
AUPRC
AUROC
F1
XGBoost
0.629 ± .003
0.652 ± .003
0.590 ± .000
MLP
0.591 ± .025
0.634 ± .014
0.593 ± .001
R-GCN
0.598 ± .006
0.648 ± .006
0.593 ± .002
SME-HGT
0.606 ± .005
0.646 ± .003
0.591 ± .001
Table 2. Test Set Results (mean ± std over 10 seeds)
Precision@ K
Lift@ K
Model
@100
@500
@1K
@100
@500
@1K
XGBoost
.924
.711
.578
2.21
1.70
1.38
MLP
.845
.668
.550
2.02
1.60
1.32
R-GCN
.826
.673
.572
1.98
1.61
1.37
HGT
.834
.689
.576
2.00
1.65
1.38
Table 3. Ranking Metrics on Test Set (mean over 10 seeds)
Removed Feature
AUPRC
Δ vs. Full
None (full model)
0.603 ± .002
—
− log total Phase I
0.597 ± .002
− 0.006
− log Phase I count
0.577 ± .003
− 0.026
− agency diversity
0.604 ± .002
+ 0.001
− years active
0.607 ± .002
+ 0.005
− log avg Phase I size
0.601 ± .002
− 0.002
Table 4. Feature Ablation (HGT, AUPRC, mean ± std over 5 seeds). Larger Δ = more important feature.
Removed Edge Type
AUPRC
Δ vs. Full
None (full model)
0.603 ± .002
—
− operates_in
0.596 ± .003
− 0.007
− awarded_by
0.594 ± .005
− 0.009
− co_topic
0.615 ± .002
+ 0.012
− co_agency
0.605 ± .005
+ 0.002
− co_state
0.601 ± .006
− 0.002
Table 5. Edge-Type Ablation (HGT, AUPRC, mean ± std over 5 seeds).
Model
Edge Mode
AUPRC
AUROC
SME-HGT
Multi
0.606 ± .003
0.647 ± .003
Single
0.599 ± .004
0.645 ± .004
R-GCN
Multi
0.607 ± .007
0.653 ± .005
Single
0.594 ± .010
0.650 ± .007
MLP
Multi
0.557 ± .070
0.608 ± .051
Single
0.557 ± .070
0.608 ± .051
Table 6. Multi-Edge vs. Single-Edge (AUPRC, mean ± std over 5 seeds).
Model
Early
Current
Late
XGBoost
0.732 ± .001
0.628 ± .005
0.548 ± .005
MLP
0.660 ± .078
0.557 ± .070
0.433 ± .086
R-GCN
0.676 ± .059
0.607 ± .007
0.483 ± .080
SME-HGT
0.717 ± .004
0.606 ± .003
0.542 ± .005
Table 7. Temporal Robustness (AUPRC, mean ± std over 5 seeds). Test periods: Early (2018–2020), Current (2020–2022), Late (2021–2023).
School of Management Science and Engineering, Central University of Finance and Economics, Beijing 100081, China · School of Computer Science, University of Sydney, NSW 2006, Australia