This paper examines the relationship between digital technology adoption
and firm productivity in Vietnamese manufacturing. Using administrative
data on 59,000 firms from Viet Nam's 2020 Enterprise Survey, we construct
a Digital Adoption Index (DAI, 0–7) and decompose it into
connectivity readiness (internet, e-commerce, website) and operational
depth (software, automation, IT investment). A one-unit DAI increase is
associated with a 3.5% increase in total factor productivity. The
decomposition reveals that the entire effect comes from operational depth, while connectivity readiness
contributes nothing. Connectivity does predict operational depth, consistent with a technology ladder
where basic access is necessary but insufficient. The digital-productivity
gradient is steepest for large and foreign-invested firms, but
insignificant for small firms.