Reconstructing the Synergy Thesis: A Critical Review of Islamic Finance, Circular Economy, and Digital Transformation for Sustainable Halal Startups

Abstract

Halal startups are increasingly framed as the convergence point of three sustainability agendas — Islamic finance, the circular economy, and digital transformation — yet estimates of the halal market's own size diverge by more than a trillion US dollars across recent Scopus-indexed sources, an inconsistency rarely acknowledged before the “synergy” argument is built on top of it. This paper offers a critical narrative review of 71 Scopus-indexed publications (2015–2026) to test how well the empirical record actually supports the synergy thesis specifically for startups, rather than for incumbent Islamic banks, established SMEs, or halal supply chains in general. Four gaps are identified. First, an evidentiary asymmetry: quantitative validation exists for adjacent constructs (fintech adoption, entrepreneurial performance, tourism barriers), but the one framework that integrates Islamic principles with digital technology for halal supply chains is itself a systematic review whose authors state that empirical validation is still required. Second, domain-boundary blurring, where several sources cited elsewhere as evidence of halal-specific digital transformation are generic Industry 4.0 or blockchain-logistics studies with no Islamic or halal content. Third, regulatory and consumer-side barriers — incomplete ASEAN harmonization, waqf administration bottlenecks, and documented non-Muslim reluctance toward halal food — persist wherever empirical evidence actually exists. Fourth, Islamic financing innovations for the circular halal economy (cash waqf-linked sukuk, green sukuk, crowdfunding) remain small-scale, jurisdiction-specific pilots never tested on startups as a distinct unit of analysis. The review concludes that the synergy thesis is conceptually coherent but empirically premature.