Vietnam and India rank among Asia's most dynamic emerging economies, each sustaining headline GDP growth rates above six percent in recent years. Yet beneath these macroeconomic achievements lies a persistent structural contradiction: the majority of workers in both countries remain in informal employment, while skills mismatches between educational outputs and labour market demands continue to widen. This paper examines how labour market informality and skills mismatch jointly constrain total factor productivity (TFP) and inclusive growth in Vietnam and India over the period 2015 - 2025. Situated within the structuralist and New Institutional Economics traditions, the study employs a comparative case study methodology combining secondary data analysis with institutional mapping. The findings reveal that both countries exhibit a "high-growth paradox" in which output expansion is driven predominantly by capital accumulation rather than efficiency gains, with informality and skills mismatch functioning as mutually reinforcing productivity drags. This paper contributes to the literature by providing the first systematic comparative analysis linking these three variables across Vietnam and India, and by deriving institutional policy lessons transferable across both contexts.