Abstract
Type of the article: Research ArticleAbstractPublic-private partnerships are a principal vehicle for infrastructure finance, yet their institutional correlates are poorly measured. This study examines how tax and customs digitalization and the oversight of PPP contracts relate to PPP deal flow, with Kazakhstan as a case. Customs digitalization is measured by WTO Trade Facilitation Agreement commitments and realized implementation in the UN survey, tax digitalization by electronic filing and payment rates, and oversight by contract-management and supreme-audit scores. Poisson and staggered-adoption models use 359 observations across 83 low- and middle-income economies (2020–2024), larger and more PPP-active than the 50 excluded, and 803 across 81 WTO members (2015–2024). Legal commitments to digital customs procedures show no association with financial closures, nor do electronic tax filing and payment. Realized implementation of electronic duty payment is associated with about 0.4 log points more closures per level; the two-year lead is insignificant, and the estimate loses significance without China, India, and Brazil. The three customs measures thus distinguish perceived trade-logistics performance, formal commitment, and realized transactional implementation. Contract-management regulatory quality (β = 0.023, p < 0.01) is associated with closures through accounting for PPP liabilities and the presence of a regulator, whereas post-project audit and supreme-audit oversight are not. In Kazakhstan, customs digitalization was complete by 2019, the 2021 amendments followed the national audit of PPP obligations, and termination rates differ across regions, not cohorts. State audit of budget execution reaches PPP obligations directly, whereas special-purpose audit applies only where the state partner is a quasi-public entity.