Net Interest Margins of Vietnamese Commercial Banks: What Really Affects?

The study analyzes the factors affecting the net interest margins (NIM) of 30 commercial banks in Vietnam in the period 2012–2020 by using the Bayesian method via Gibbs sampling algorithm. The dependent variable in the research model is the NIM of Vietnamese commercial banks. The research model includes six independent variables: bank size, bank capital, operating costs, bank loans, inflation, and GDP growth. The research results show that the factors that positively affect the NIM of banks include bank size, bank capital, operating costs, outstanding loans, and inflation. Meanwhile, GDP growth has the opposite effect.