Firm Size Distribution, Production Efficiency, and Returns to Scale: A Stochastic Frontier Approach

This paper empirically investigates the relationship between firm size, production efficiency, and returns to scale. Using a recently developed stochastic frontier approach and data from Vietnam, our analysis shows that across all of the sectors we consider, production efficiency is most variable among middle-sized firms, with these firms across all sectors tending to have the lowest production efficiency. While most firms across different sized groups show constant returns-to-scale technologies, our analysis using Spearman coefficients shows that there is a significant difference in technologies and this difference varies substantially across size groups in all sectors. Furthermore, we show that the least-efficient size also differs across sectors. Although our analysis is a snapshot of the Vietnamese manufacturing industry, the diverse production efficiencies in the middle-sized groups can be thought of as a risk that small-sized firms would face in expanding their business.