Liu, M.H. and Guo, Y.C. 2026. Incremental vs. Stock: Evaluating the Impact of VAT Credit Refunds on Corporate Productivity with Evidence from Difference-in-Differences and Machine Learning Heterogeneity Analysis. Advanced Electromagnetics. 15, 3 (Aug. 2026), 4230–4248. DOI:https://doi.org/10.7716/aem.v15i3.3486.