Bribing doctors for preferential treatment is rampant in the Vietnamese healthcare system, which is commonly deemed an “envelope culture.” This study employed the mindsponge theory for reasoning the mental processes of both patients and doctors for why they embrace the “envelope culture”.

The Bayesian Mindsponge Framework (BMF) analytics was employed on a dataset of 1042 Vietnamese patients to validate our reasoning.

The study discovered that bribing doctors can help patients reduce the destitution risk induced by treatment. Such effect of doctor bribery remains consistent among patients who pay high daily costs (e.g., accommodation and subsistence fees) regardless of their employment status. Nevertheless, for patients with no or unstable jobs, their risks of destitution increase if they have to pay more thank-you money.

These findings suggest that doctor bribery is an adaptive strategy for patients in an environment where the healthcare supply cannot meet the actual demand. Moreover, healthcare equity is greatly exacerbated, as vulnerable individuals are exposed to a greater threat of poverty.